Timepiece component and method for manufacturing same

Abstract

The timepiece component (1) comprises a base plate (11) made of an at least partially transparent material, and a first colored enamel layer (12) applied to the base plate (11) by transfer printing, in particular by pigmented decal.

Description

Field of the Invention

[0001] The present invention relates to a clock part. The present invention also relates to a clock including such a clock part. The present invention finally relates to a method for manufacturing such a clock part. Background Art

[0002] In the field of clocks, and particularly in the field of outer parts of watches, there is a search for obtaining, in a reliable, robust and reproducible manner, an ornamental and durable outer ring, that is to say, a ring whose decoration can vary for any design without restricting the choice of colors or their combinations to obtain a monochromatic or polychromatic result, and which is resistant to aging and environmental damage (scratches, UV rays, etc.), without having to adjust the technical processes of the clock to achieve these objectives.

[0003] Documents CH707424A2 and CH707423A2 describe the production of parts made of opaque technical ceramics (such as alumina or zirconia), which parts have a decoration formed by impregnating metal salts on the face of the part visible to the clock user. It is difficult to obtain all color combinations using the described methods.

[0004] Patent EP1734420B1 describes a transparent watch glass that is locally glazed on its lower face in order to help mask the system for assembling the glass to the intermediate case. In this patent, a sealed case is mainly claimed, which sealed case includes an intermediate piece and a bottom cover that define a receiving portion, which receiving portion is closed by a glass made of a transparent material resistant to temperatures higher than 500 °C, glued or welded at the level of a joint area that at least partially covers the shoulder of the intermediate piece, wherein the inner face of the glass includes an enamel deposit formed at the level of the joint area.

[0005] Patent CH320817 describes a rotating outer ring including a transparent disk, the lower face of said transparent disk:

[0006] - is recessed in order to form hour markers (indications), said recesses being coated with a metal deposit that colors the hour markers,

[0007] - and is also coated, for example, with a varnish in order to give a colored appearance to the disk outside the recesses.

[0008] The transparent disk allows the metal-colored indications to be seen, in contrast to the color applied to its lower face. An example is given where this color is the color of the varnish.

[0009] Document WO2006 / 133810A1 discloses a component and a method for obtaining the same. The component includes a transparent substrate decorated with an enamel layer disposed in a recess. The variation in the enamel color tone described in this document is produced by the variation in the enamel thickness, which is controlled by the depth of the recess in which the enamel is deposited (these recesses are on the face and / or side of the component). For a single composition of enamel, this produces a series of color tones. Summary of the Invention

[0010] An object of the present invention is to provide a clock component that can improve the components known in the prior art. In particular, the present invention proposes a clock component that can be decorated in a simple manner and provides high durability of the decoration formed on the component, without the need to use dedicated devices for forming and protecting the decorative surface to design the rest of the clock.

[0011] The object of the first aspect of the present invention is defined by the following proposal:

[0012] 1. A clock component (1), comprising:

[0013] - a substrate (11) made of at least partially transparent material, and

[0014] - a first layer (12) of colored enamel applied to the substrate (11) by transfer, in particular by chromo decal.

[0015] 2. The clock component (1) according to proposal 1, wherein the clock component (1) includes a second decorative layer (13) at least partially applied to the first layer (12) of colored enamel, in particular a light-shielding second decorative layer (13).

[0016] 3. The clock component (1) according to proposal 1 or 2, wherein the substrate is made of an inorganic material, such as technical ceramics, quartz, spinel, magnesium aluminate, AlON, YAG, cubic zirconia, mineral glass, polycrystalline alumina, glass-ceramics, single-crystalline alumina, and / or the substrate has an actual linear light transmittance of greater than 60% or 70% or 80% or 85% for light with a wavelength of 550 nm at least locally.

[0017] 4. The clock component (1) according to any one of proposals 1 to 3, wherein the substrate has a hardness greater than 800 Hv or 1000 Hv.

[0018] 5. The clock component (1) according to any one of proposals 1 to 4 and proposal 2, wherein the second decorative layer is:

[0019] - an enamel layer, in particular an enamel layer applied by transfer, and / or

[0020] - a metal substrate layer, especially a metal substrate layer deposited by PVD, CVD, ALD, or PLD, and / or

[0021] - another coating layer, such as a paint layer.

[0022] 6. The timepiece component (1) according to any one of Proposals 1 to 5, wherein the timepiece component (1) is an external housing component of a timepiece (100), such as in particular:

[0023] - glass,

[0024] - a back cover,

[0025] - an outer ring disc,

[0026] - a wristband element, or

[0027] - a middle piece,

[0028] Alternatively, the timepiece component (1) is an internal component of the timepiece (100), such as in particular:

[0029] - a dial,

[0030] - a flange, or

[0031] - a disc for displaying timepiece information.

[0032] 7. The timepiece component (1) according to any one of Proposals 1 to 6, wherein:

[0033] - the substrate (11) includes a first surface (111) and a second surface (112), especially a second surface (112) that is parallel to or substantially parallel to the first surface (111),

[0034] - the first layer (12) and / or the second layer (13) is applied to the first surface (111), and

[0035] - the first surface (111), especially the first layer and / or the second layer applied to the first surface, can be seen through the second surface (112) and the substrate (11).

[0036] 8. The timepiece component (1) according to Proposal 7, wherein the substrate (11) includes at least one second recess (15) formed on the second surface (112), especially at least one second recess (15) formed by laser machining.

[0037] 9. The timepiece component (1) according to Proposal 8, wherein the at least one second recess (15) has a coating, especially a coating of a metal substrate layer, especially a metal substrate layer deposited by PVD, CVD, ALD, or PLD.

[0038] 10. A clock part (1) according to any one of proposals 7 to 9, wherein the substrate (11) has an anti-reflection treatment on the second surface (112).

[0039] 11. A clock part (1) according to any one of proposals 1 to 10 and proposal 7, wherein the substrate (11) comprises at least one first recess (14) formed on the first surface (111) after applying the first layer and the second layer, in particular at least one first recess (14) formed by laser machining.

[0040] 12. A clock part (1) according to proposal 11, wherein the at least one first recess (14) has a coating, in particular a metal base layer is coated, in particular a metal base layer deposited by PVD, CVD, ALD or PLD.

[0041] 13. A clock part (1) according to proposal 11 or 12, wherein the at least one first recess (14) is such that the material area removed by ablation in a plane perpendicular to the direction in which the at least one first recess is formed is arranged between the following surfaces:

[0042] - the surface forming the at least one first recess, in particular the lower surface (111) or the surface of the first layer (12) or the surface of the second layer (13), and

[0043] - the surface defining the bottom of the at least one first recess,

[0044] and varies in the direction in which the at least one first recess is formed,

[0045] and / or

[0046] the at least one first recess (14) is such that the material area removed by ablation in any plane parallel to the direction in which the at least one first recess is formed varies in a direction orthonormal to the direction in which the at least one first recess is formed.

[0047] 14. A clock part (1) according to any one of proposals 11 to 13, wherein the at least one first recess (14) has an area at the millimeter or micron or nanometer scale, in particular at the level of the surface defining the bottom of the recess and / or at the level of the surface forming the recess.

[0048] 15. A method for producing a clock part (1), the method comprising the following steps:

[0049] - obtaining a substrate (11) made of at least partially transparent material, and

[0050] - Apply a first layer (12) of colored enamel to the substrate (11), in particular by transfer printing, in particular by pigment decalcomania.

[0051] 16. The method according to claim 15, wherein the method comprises applying at least partially a second decorative layer (13), in particular a light-shielding second decorative layer (13), to the first layer (12) of colored enamel.

[0052] 17. The production method according to claim 16, wherein applying the second layer is:

[0053] - Apply an enamel layer, in particular by transfer printing, in particular by pigment decalcomania, and / or

[0054] - Apply a metal base layer, in particular by PVD, CVD, ALD, PLD, and / or

[0055] - Apply another coating layer, such as a paint layer.

[0056] 18. The production method according to any one of claims 15 to 17, wherein the production method comprises the step of forming at least one first recess (14), in particular at least one first recess (14) formed by laser machining, on a first surface (111) of the substrate (11), and / or the production method comprises the step of forming at least one second recess (15), in particular at least one second recess (15) formed by laser machining, on a second surface (112) of the substrate (11).

[0057] 19. The production method according to claim 18, wherein the step of forming at least one first recess and / or the step of forming at least one second recess are carried out after the step of applying the first enamel layer (12) to the substrate (11), and in the step of forming at least one first recess and / or in the step of forming at least one second recess, the decoration formed by the first enamel layer is used as a mark, in particular as a processing mark.

[0058] 20. The production method according to any one of claims 18 and 19, wherein the method comprises the step of coating the at least one first recess (14) and / or the at least one second recess (15), in particular coating with a metal base layer, in particular with a metal base layer deposited by PVD, CVD, ALD or PLD.

[0059] 21. A clock part (1) obtained by using the method according to any one of claims 15 to 20.

[0060] 22. A timepiece (100) comprising a timepiece component (1) according to any one of proposals 1 to 14 and 21, in particular a timepiece component (1) according to any one of proposals 7 to 14, the timepiece component (1) being arranged such that the first surface (111), in particular the first layer (12) and / or the second layer (13), can be seen by the wearer of the timepiece (100) through the second surface (112) and the substrate (11).

[0061] According to a second aspect of the invention, the object is defined by the following proposals.

[0062] 23. A timepiece component (1) comprising:

[0063] - a substrate (11) made of at least partially transparent material

[0064] - a first layer (12) of colored enamel applied to the substrate (11), in particular by transfer, in particular by pigment decal, and

[0065] - a second decorative layer (13) applied at least partially to the first layer (12) of colored enamel, in particular a light-shielding second decorative layer (13).

[0066] 24. The timepiece component (1) according to proposal 23, wherein the substrate is made of an inorganic material such as technical ceramics, quartz, spinel, magnesium aluminate, AlON, YAG, cubic zirconia, mineral glass, polycrystalline alumina, glass ceramic, single crystal alumina, and / or the substrate has a real linear light transmittance of greater than 60% or 70% or 80% or 85% for light with a wavelength of 550 nm at least locally.

[0067] 25. The timepiece component (1) according to proposal 23 or 24, wherein the substrate has a hardness greater than 800 Hv or 1000 Hv.

[0068] 26. The timepiece component (1) according to any one of proposals 23 to 25, wherein the second decorative layer is:

[0069] - an enamel layer, in particular an enamel layer applied by transfer, and / or

[0070] - a metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD, PLD, and / or

[0071] - another coating layer, such as a paint layer.

[0072] 27. The timepiece component (1) according to any one of proposals 23 to 26, wherein the timepiece component (1) is an external housing component of a timepiece (100), for example in particular:

[0073] - glass,

[0074] - bottom cover,

[0075] - outer ring disc,

[0076] - wristband element, or

[0077] - middleware,

[0078] Alternatively, the clock component (1) is an internal component of the clock (100), such as in particular:

[0079] - dial,

[0080] - flange, or

[0081] - disc for displaying clock information.

[0082] 28. The clock component (1) according to any one of proposals 23 to 27, wherein:

[0083] - The substrate (11) includes a first surface (111) and a second surface (112), in particular a second surface (112) parallel to or substantially parallel to the first surface (111),

[0084] - The first layer (12) and / or the second layer (13) are applied to the first surface (111), and

[0085] - The first surface (111), in particular the first layer and / or the second layer applied to the first surface, can be seen through the second surface (112) and the substrate (11).

[0086] 29. The clock component (1) according to proposal 28, wherein the substrate (11) includes at least one second recess (15) formed on the second surface (112), in particular at least one second recess (15) formed by laser processing.

[0087] 30. The clock component (1) according to proposal 29, wherein the at least one second recess (15) has a coating, in particular a coating of a metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD or PLD.

[0088] 31. The clock component (1) according to any one of proposals 28 to 30, wherein the substrate (11) has an anti-reflection treatment on the second surface (112).

[0089] 32. A clock component (1) according to any one of proposals 23 to 31 and proposal 28, wherein the substrate (11) includes at least one first recess (14) formed on the first surface (111) after applying the first layer and the second layer, in particular at least one first recess (14) formed by laser machining.

[0090] 33. The clock component (1) according to proposal 32, wherein the at least one first recess (14) has a coating, in particular a metal base layer is coated, in particular a metal base layer deposited by PVD, CVD, ALD or PLD is coated.

[0091] 34. The clock component (1) according to proposal 32 or 33, wherein the at least one first recess (14) is such that the material removal area by ablation on the level of a plane perpendicular to the direction of forming the at least one first recess is arranged between the following surfaces:

[0092] - the surface forming the at least one first recess, in particular the lower surface (111) or the surface of the first layer (12) or the surface of the second layer (13), and

[0093] - the surface defining the bottom of the at least one first recess,

[0094] and varies in the direction of forming the at least one first recess,

[0095] and / or

[0096] the at least one first recess (14) is such that the material removal area by ablation on the level of any plane parallel to the direction of forming the at least one first recess varies in a direction standard orthogonal to the direction of forming the at least one first recess.

[0097] 35. The clock component (1) according to any one of proposals 32 to 34, wherein the at least one first recess (14) has an area in millimeters or micrometers or nanometers, in particular on the level of the surface defining the bottom of the recess and / or on the level of the surface forming the recess.

[0098] 36. A method for producing a clock component (1), the method comprising the following steps:

[0099] - obtaining a substrate (11) made of at least partially transparent material,

[0100] - applying a first layer (12) of colored enamel to the substrate (11), in particular applying the first layer (12) of colored enamel to the substrate (11) by transfer, in particular applying the first layer (12) of colored enamel to the substrate (11) by pigment decal, and

[0101] - Apply the second decorative layer (13), in particular a light-shielding second decorative layer (13), at least partially onto the first layer (12) of colored enamel.

[0102] 37. The production method according to Proposal 36, wherein applying the second layer is:

[0103] - Apply an enamel layer, in particular by transfer printing, in particular by pigment decal, and / or

[0104] - Apply a metal base layer, in particular by PVD, CVD, ALD, PLD, and / or

[0105] - Apply another coating layer, such as a paint layer.

[0106] 38. The production method according to Proposal 36 or 37, wherein the production method includes the step of forming at least one first recess (14), in particular at least one first recess (14) formed by laser processing, on the first surface (111) of the substrate (11), and / or the production method includes the step of forming at least one second recess (15), in particular at least one second recess (15) formed by laser processing, on the second surface (112) of the substrate (11)

[0107] 39. The production method according to Proposal 38, wherein the step of forming at least one first recess and / or the step of forming at least one second recess is carried out after the step of applying the first enamel layer (12) onto the substrate (11), and in the step of forming at least one first recess and / or in the step of forming at least one second recess, the decoration formed by the first enamel layer is used as a mark, in particular as a processing mark.

[0108] 40. The production method according to any one of Proposals 38 and 39, wherein the method includes the step of coating the at least one first recess (14) and / or the at least one second recess (15), in particular coating with a metal base layer, in particular with a metal base layer deposited by PVD, CVD, ALD or PLD.

[0109] 41. A clock part (1) obtained by using the method according to any one of Proposals 36 to 40.

[0110] 42. A timepiece (100) comprising a timepiece component (1) according to any one of claims 25 to 35 and 41, in particular a timepiece component (1) according to any one of claims 30 to 35, the timepiece component (1) being arranged such that the first surface (111), in particular the first layer (12) and / or the second layer (13), can be seen by the wearer of the timepiece (100) through the second surface (112) and the substrate (11). Description of the Drawings

[0111] Figure 1 is a schematic view of an embodiment of a timepiece according to the invention, in which the timepiece component is shown in cross-section. Detailed Description

[0112] A particular embodiment of the timepiece 100 will be described below with reference to Figure 1 in detail.

[0113] The timepiece 100 is, for example, a watch, in particular a wristwatch. The timepiece 100 comprises a component that includes:

[0114] - a timepiece movement, and

[0115] - a dial.

[0116] This component is intended to be installed in a case or timepiece housing to protect it from the external environment.

[0117] The timepiece movement can be a mechanical movement, in particular an automatic movement, or a hybrid movement. Alternatively, the movement can be an electronic movement.

[0118] The timepiece 100, in particular the component or the housing or the dial or the movement, includes a timepiece component 1. The timepiece component 1 can, for example, be an external housing component of the timepiece 100, such as in particular:

[0119] - a glass,

[0120] - a back cover,

[0121] - an outer bezel,

[0122] - a bracelet element, or

[0123] - a middle case.

[0124] Alternatively, the timepiece component 1 can be an internal component of the timepiece 100, such as in particular:

[0125] - a dial,

[0126] - a flange, or

[0127] - a disk for displaying timepiece information.

[0128] The timepiece component 1 includes:

[0129] - A substrate 11 made of at least partially transparent material, and

[0130] - A first layer 12 of colored enamel applied to the substrate 11, in particular by transfer, and in particular a first layer 12 of colored enamel applied to the first surface 111 of the substrate 11.

[0131] "Layer of colored enamel" means an enamel layer with a color visible to the naked eye, regardless of the color of the area. Thus, the color can in particular be achromatic (white, grey or black). Thus, the "colored layer" gives the watch part an overall hue or contributes to the hue of the watch part. Then, the final color or the resulting color of the watch part is a combination of the color of this colored layer (adjusted by the color of a possible second decorative layer) and the color of the substrate (if the substrate is uncolored). The substrate is preferably uncolored, and the resulting color of the watch part is preferably the hue produced by the first enamel layer 12 and a possible second decorative layer 13. The substrate is preferably made of sapphire, uncolored single-crystal alumina, and the resulting color of the watch part is preferably the hue produced by the first enamel layer 12 and a possible second decorative layer 13.

[0132] Preferably:

[0133] - The watch part includes a first layer 12 of colored enamel applied to the substrate 11, in particular to the first surface 111 of the substrate 11, by pigment decal, and / or

[0134] - The watch part includes a second layer 13 as a decorative, support or light-shielding layer. The second layer 13 is at least partially applied on top of the first layer 12. The function of the second layer 13 is in particular to provide a backing for the color of the colored enamel.

[0135] "Decorative layer" means the second layer in the two stacked layers envisaged, i.e. the layer that completes the stack or covers the first layer. Where there is a first layer and a decorative layer, the first layer is between the substrate and the decorative layer. The function of the decorative layer is as a backing layer or a light-shielding layer, i.e. a layer that reduces or eliminates the transparency of the decoration formed by the colored layer, or more generally a layer that provides a backing for the color of the first colored layer.

[0136] "Backing layer" means a layer that enhances or modifies the color of the first layer.

[0137] "Opaque layer" or "light-shielding layer" means an opaque layer, in particular an opaque enamel layer. Compared with the transparency of a structure without an opaque layer applied alone, the opaque layer reduces the transparency of the component formed by it together with the structure to which it is applied. The opaque layer eliminates the overall transparency of the component formed by it together with the structure to which it is applied, regardless of the transparency of the structure. In fact, it is impossible to see through the opaque layer.

[0138] The component is advantageously arranged in the timepiece 100 such that the wearer of the timepiece 100 can see the first layer 12 and / or the second layer 13 through the substrate 11. In other words, the wearer or user of the watch advantageously sees through the substrate the side of the first layer that is in contact with the substrate 11. The component is produced to be arranged in this configuration.

[0139] The first layer and / or the second layer form a decoration, that is to say, preferably:

[0140] - graphic elements, or

[0141] - patterns, or

[0142] - a combination of multiple graphic elements and / or patterns, or

[0143] - complex designs.

[0144] The decoration can be monochromatic or formed by multiple colors.

[0145] The main function of the first layer and / or the second layer is decorative. The said layer(s) can also very well completely hide the elements located behind the timepiece component 1 in order to expose certain areas by means of transparency.

[0146] According to a variant, when the timepiece component 1 is installed in the rest of the timepiece, no element:

[0147] - is in contact with the second layer 13, or

[0148] - is in contact with the first layer 12 in the absence (possibly partial absence) of the second layer.

[0149] The timepiece component 1 has the overall shape of a substrate, and the substrate 11 constitutes most of the timepiece component 1.

[0150] As Figure 1 shown, the substrate 11 includes a first surface 111 and a second surface 112, in particular parallel or substantially parallel first surface 111 and second surface 112. Each of the first surface 111 and the second surface 112 can be of any kind, in particular a planar, frustoconical, partially annular, dome-shaped concave or dome-shaped convex geometry.

[0151] For example, in Figure 1In it, surfaces 111 and 112 form the faces of the component. These faces are parallel. Alternatively, they can be non-parallel. Suppose the clock component 1 consists of an outer ring disk. The first surface and the second surface are preferably two parallel frustoconical surfaces, for example.

[0152] Note that in Figure 1 the first layer 12 has been applied to the first surface 111. The first layer may have been applied to the entire first surface 111 or only to a part of the first surface 111, as Figure 1 shown.

[0153] Similarly, note that in Figure 1 the second layer 13 has been applied to the assembly formed by the first layer 12 and a part of the first surface 111 of the substrate, facing or vertically aligned with the first surface 111. Like the first layer, the second layer can be applied vertically aligned with the entire first surface 111 or only vertically aligned with a part of the first surface 111, as Figure 1 shown.

[0154] Thus, depending on the region of the relevant first surface, in the material of the clock component, starting from the first surface 111 and traveling towards the outside of the component (perpendicular to the first surface 111), it is possible to:

[0155] - encounter the first layer 12 and then the second layer 13, or

[0156] - encounter only the first layer 12, or

[0157] - encounter only the second layer 13, or

[0158] - encounter no layer (the substrate has no coating in the relevant region of the first surface 111).

[0159] Since the substrate 11 is transparent, the first surface 111 can be seen through the second surface 112 and the substrate 11, especially the first layer 12 and / or the second layer 13 applied to the first surface.

[0160] The substrate is preferably based on or made of an inorganic material, such as:

[0161] - technical ceramics,

[0162] - quartz,

[0163] - spinel,

[0164] - magnesium aluminate,

[0165] - AlON (aluminum oxynitride),

[0166] - YAG (yttrium aluminum garnet),

[0167] - Cubic zirconia,

[0168] - Mineral glass,

[0169] - Polycrystalline alumina,

[0170] - Glass ceramic,

[0171] - Single crystal alumina (sapphire).

[0172] The first surface 111 preferably has a mirror-polished surface state and / or the second surface 112 preferably has a mirror-polished surface. However, at least the first surface 111 and the second surface 112 may have a rough surface state, such as a frosted surface state. Such a rough surface state can be obtained in particular by sandblasting and / or sanding and / or brushing; it can be produced by conventional tools and / or by laser. This makes it possible to impart a matte appearance to the watch part 1. Alternatively, this makes it possible to impart a matte appearance to at least a part of the watch part 1 at the level of the part of the watch part where the rough surface state is produced.

[0173] The substrate is at least partially transparent. The substrate is preferably transparent and uncolored. More generally, the substrate can be made of a material that is at least partially transparent.

[0174] "At least partially transparent" means that:

[0175] - The substrate includes at least one transparent region, and / or

[0176] - At least one area of the substrate or the entire substrate has a certain degree of transparency, and some light does not transmit through the substrate. For example, this includes a translucent substrate or a substrate whose "actual direct light transmittance for light with a wavelength of 550 nm is greater than 60%, even 70%, even 80%, even 85%". In other words, there is at least one such position on the substrate where at least 60%, even at least 70%, even at least 80%, even at least 85% of the light with a wavelength of 550 nm can pass through the substrate from the second surface to reach the first surface. According to the paper E6418 v1 by Rémy Boulesteix and Alexandre Maitre (10.07.2018) titled "Céramiques transparentes - Caractéristiques générales et procédés de fabrication" from "Les Techniques de l’Ingénieur", transparency can actually be characterized by measuring the "actual direct light transmittance" (RIT) of light. It is achieved using a spectrophotometer with a small aperture angle (about 0.5°). It corresponds to the ratio of the intensity of the light transmitted through the material sample to the incident intensity. This RIT transparency depends on the thickness (x) of the sample, the wavelength (λ) of the light, and is given by the Beer-Lambert law:

[0177] RIT(λ) = [1 - Rs(λ)].e -α(λ).x

[0178] where Rs is the loss due to reflection at the two surfaces of the sample; they are approximately 0.14 to 0.16, and can be evaluated using the following formula:

[0179] Rs = 2.R’(λ) / [1 + R’(λ)]

[0180] where, at normal incidence, R’ = {[n(λ) - 1] / [n(λ) + 1]} 2

[0181] where n is the refractive index of the material, and α(λ) is the attenuation coefficient of the material, which takes into account the optical losses caused by various dispersion or absorption sources of the light passing through the material.

[0182] For example, the substrate can be colored.

[0183] The manner of implementing the production method of the above-mentioned clock component 1 will be described below.

[0184] Generally speaking, the production method includes the following steps:

[0185] - Obtaining a substrate 11 made of at least partially transparent material, and

[0186] - Apply a first layer 12 of colored enamel to the surface of the substrate 11, in particular by transfer application.

[0187] Preferably:

[0188] - Applying the first layer 12 of colored enamel to the substrate 11 can be carried out by applying a pigment decal to the substrate 11, in particular to the first surface 111 of the substrate 11, and / or

[0189] - The method may include applying a second decorative layer 13 at least partially over the first layer 12 of colored enamel.

[0190] In other words, the solution which is the subject of this document depends on the specific use of enamel deposited by pigment decal (or enamel decal; the expressions "enamel decal" and "pigment decal" are considered equivalent) on the surface intended to be seen by the user of the watch through the substrate 11. This is preferably carried out in two stages:

[0191] - The first layer of colored enamel visible through the substrate represents the decoration,

[0192] - The second decorative enamel layer eliminates the transparency of the decoration, or more generally, enhances the color of the first layer of colored enamel. The second enamel layer is preferably opaque. The second enamel layer is preferably opaque and white.

[0193] This makes it possible to obtain a decorative and durable watch part (such as an outer bezel) in a reliable, robust and reproducible manner.

[0194] The second decorative layer or decorative backing layer or opaque layer can be:

[0195] - An enamel layer, in particular an enamel layer applied by transfer, in particular an enamel layer applied by pigment decal, and / or

[0196] - A metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD, PLD, and / or

[0197] - Another coating layer, such as a paint layer.

[0198] According to the invention, in order to produce a watch part 1, for example in order to produce an outer bezel, the procedure is preferably as follows:

[0199] - Obtain a transparent, preferably sapphire, substrate,

[0200] - Apply an enamel decoration to the surface of the substrate intended to be seen through the substrate by pigment decal,

[0201] - Apply a decorative layer or backing layer or light-shielding layer on top of the enamel decoration.

[0202] In contrast, in the traditional way, in order to produce the clock part 1, especially in order to produce the outer ring plate,

[0203] - Obtain a substrate (usually opaque in the case of clock decoration),

[0204] - Optionally apply an underlayer to the surface of the substrate, on which the user will see the underlayer in the absence of a coating,

[0205] - Apply enamel decoration to the said surface of the substrate that may be pre-covered with an underlayer,

[0206] - Apply glaze (colorless transparent enamel) on the enamel decoration.

[0207] In the case of using this clock part in the outer case of a watch, it is found that the outer surface of the part may be very frequently eroded by the external environment. If the decoration is deposited on this outer surface, this may reduce the durability of the decoration integrity. The solution to this problem is provided by the solution according to the present invention by exposing the bare surface of the part to such erosion, thereby protecting the decoration placed on the more concealed surface visible through the transparent substrate.

[0208] More specific uses are described in more detail below.

[0209] In the first step, obtain the substrate 11 to be decorated. This substrate forms part of the clock part 1, preferably most of the clock part 1.

[0210] This substrate must withstand the glazing conditions. Therefore, it must withstand a temperature higher than 500 °C, preferably higher than 750 °C, so that the enamel can be vitrified without suffering damage such as deformation or oxidation.

[0211] In addition, the substrate must preferably have a hardness sufficient to be able to resist wear. The material constituting the substrate preferably has a Vickers hardness greater than 800 Hv, even greater than 1000 Hv. This is more important if the part is an outer case part that may be exposed to mechanical erosion.

[0212] In the second step, apply the first enamel layer. For this purpose, apply the decoration to the substrate 11, especially to the first surface 111 of the substrate 11. This decoration is preferably applied by pigment decal. Preferably, one or more pigment decals are applied to the substrate 11, especially to the first surface 111 of the substrate 11, that is, the enamel layer is applied by the transfer of one or more pigments (chromo). Different pigments (for example, pigments of different colors) may be applied juxtaposed or non-juxtaposed to different regions of the first surface 111, and / or may be at least partially stacked.

[0213] On the transfer paper, a decoration with a pattern determined by pigments is prepared in advance, for example, by screen printing, lithography, chromolithography. The pigment consists of a colored film deposited on the transfer paper, and one surface of the colored film is intended to contact the first surface 111 of the substrate 11 during transfer.

[0214] The film consists of enamel powder mixed with a polymer, and the polymer generates its cohesive force. The film can be transferred (or moved or positioned) from the transfer paper to the first surface of the substrate to produce a decoration.

[0215] For example, before or after applying the film to the substrate (depending on whether the transferred pattern is on the front or back), the pigment is applied by wetting in water to separate the film from the transfer paper. Then, for example, any water and air bubbles that may be found between the substrate and the film are expelled by an elastomeric squeegee. Then it is dried, especially air-dried.

[0216] Finally, the substrate on which the film is deposited is baked. The film consists of enamel powder mixed with a polymer, and the curing is used on the one hand to remove the polymer and on the other hand to vitrify the enamel. This curing can be carried out in an oven, in the open air, at a high temperature. The vitrification heat treatment usually lasts for several minutes, usually 15 minutes, at a temperature above 500 °C, preferably above 750 °C. After this step, the substrate is decorated with a colored enamel layer.

[0217] The thermal expansion coefficient of the enamel used in the pigment must be the same as, very close to, or compatible with the thermal expansion coefficient of the substrate to ensure proper retention (adhesion) and aesthetics (that is, excluding phenomena such as cracks, crazing, or peeling). Layer 12 is very thin, and the tolerance of the difference in thermal expansion coefficient between this layer 12 and the substrate 11 is greater than that in the case of depositing a thick layer (for example, by traditional enamel deposition): Therefore, in the case of pigments, a difference of up to 5%, even 10%, even 15%, even 20%, even 25% can be envisaged. After curing, the pigment layer usually has a thickness of about 5 μm to 20 μm, even 7 μm to 10 μm (when it is original, it can correspond to a thickness of 40 μm to 80 μm). This is why it is considered thin compared to a traditionally deposited enamel layer that is considered thick (usually, after curing, it is greater than 100 μm, even greater than 200 μm, even greater than 300 μm thick). Since for the same thickness, the color of the pigment is more saturated than that of the enamel deposited in the traditional way, such a thin pigment can be used.

[0218] Alternatively, the enamel can be deposited by transfer printing or direct screen printing to form a decoration. Alternatively, the enamel can also be deposited in a traditional way (for example, by brush).

[0219] According to the required aspects, the steps of forming the first layer can be repeated. Thus, the first enamel layer constituting the decoration (especially a colored decoration) can be a multi-layer enamel. In this second step, curing is preferably carried out between each application of the enamel layer onto the substrate 11, especially on the first surface 111 of the substrate 11 or on a previously applied layer. Alternatively, in this second step, a single curing operation can be carried out after all the enamel layers have been applied.

[0220] In an optional third step, a second layer 13 is applied. The second layer is preferably a decorative layer or a backing layer or a light-shielding layer. The second layer is at least semi-transparent and ideally light-shielding. The second layer is preferably a uniform white and / or opaque enamel layer. The second layer at least partially covers the decoration formed by the first layer during the second step.

[0221] As in the second step, curing is carried out after the application of the second layer, resulting in the vitrification of the enamel and, if the enamel of the second layer is formed using pigments, possibly resulting in the removal of polymers.

[0222] For the above reasons, the coefficient of thermal expansion of the enamel for the second layer 13 must be the same as or very close to or compatible with the coefficient of thermal expansion of the layer on which it is deposited. For the combination of the thin layers 12 and 13, the tolerance of the difference in the coefficient of thermal expansion between these layers and the substrate 11 is greater than in the case of depositing thick layers, which provides more possibilities in terms of adhesion and aesthetics.

[0223] This second layer or decorative layer 13 is preferably applied by transfer, especially by pigment decal, as in the case of decorating in the second step.

[0224] Alternatively, the second layer 13 can equally be applied by other techniques (pad printing, brush, screen printing, etc.).

[0225] This third step can be carried out according to different variants:

[0226] - The second layer can be of any color. Any enamel color can be envisaged. The color of the second layer can vary according to its position on the decoration and / or on the substrate.

[0227] - The opacity of the second layer can vary: depending on the nature of one or more decorative layers, different opacity levels can be envisaged, from semi-transparent to completely opaque. Depending on the position where the decorative layer is applied to the decoration and the substrate, the target opacity can equally vary.

[0228] - The chemical nature of the decorative layer can vary: any type of inorganic material meeting the criteria of opacity and resistance to environmental stress can be envisaged. The chemical nature of the decorative layer can equally vary according to its position on the decoration. For example:

[0229] * enamel filled with luminescent zirconia powder or another luminescent inorganic material, or

[0230] * metallization, or

[0231] * a metal base layer deposited, for example, by PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), PLD (Pulsed Laser Deposition) or any other suitable process, especially nitrides,

[0232] can be used as a decorative layer.

[0233] - Thus, depending on the nature of the layer, its thickness, the target accuracy level (in terms of position, thickness, distribution, etc.), the method of applying the decorative layer can be by means of transfer, brush, screen printing, PVD, CVD, ALD, PLD, etc.

[0234] - The decorative layer is at least positioned at some of the positions decorated during the second step.

[0235] - The distribution of the decorative layer can vary on the first surface 111:

[0236] * The decorative layer can be only positioned at the positions decorated during the second step, in which case it can be applied to the whole or part of the decoration,

[0237] * The decorative layer can additionally be positioned at the positions not decorated during the second step, in which case it can be at some or all of the non - decorated positions.

[0238] - The thickness of the decorative layer can vary:

[0239] * This thickness can define its opacity level, which can be selected according to the position where it is applied,

[0240] * This thickness can adjust the hue produced by the stacking of the first layer 12 and the second layer 13.

[0241] Depending on the way the method is carried out, applying the second layer can be:

[0242] - Applying an enamel layer, especially by transfer, especially by pigment decal, and / or

[0243] - Applying a metal base layer, especially by PVD, CVD, ALD, PLD, and / or

[0244] - Applying another coating layer, such as a paint layer.

[0245] Many variant embodiments can be considered. In particular, one or more recesses can be formed on the first surface 111 of the clock part, and / or one or more recesses can be formed on the second surface 112 of the clock part.

[0246] One or more recesses on the first surface and / or the second surface can be formed before the second and third steps described above, and / or

[0247] One or more recesses on the first surface and / or the second surface can be created between the second and third steps described above, and / or

[0248] One or more recesses on the first surface and / or the second surface can be formed after the second and third steps described above.

[0249] When a recess is formed at the level of the first surface after curing the first layer, the recess may affect:

[0250] - Only a partial thickness of the first layer, or

[0251] - The entire thickness of the first layer, or

[0252] - The entire thickness of the first layer and a partial thickness of the substrate 11.

[0253] When a recess is formed at the level of the first surface after forming the first and second layers, the recess may affect:

[0254] - Only a partial thickness of the second layer, or

[0255] - The entire thickness of the second layer, or

[0256] - The entire thickness of the second layer and a partial thickness of the first layer, or

[0257] - The entire thickness of the second layer and the entire thickness of the first layer, or

[0258] - The entire thickness of the second layer and the entire thickness of the first layer and a partial thickness of the substrate 11.

[0259] Thus, according to a variant embodiment, at least one first recess 14 can be formed on the first surface 111, in particular at least one first recess 14 formed by laser machining, and / or at least one second recess 15 can be formed on the second surface 112, in particular at least one second recess 15 formed by laser machining. The method preferably includes the step of coating at least one first recess 14 and / or at least one recess 15 with a metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD or PLD.

[0260] The recess can naturally have any shape or geometry.

[0261] In particular, regardless of the position of the recess, the thickness of the material being machined to form the recess can be the same. Thus, the depth of the recess can be constant, and the distance separating the following surfaces (measured perpendicular to the surface on which the recess is formed) can be the same and corresponds to the depth of the recess regardless of the position of the recess:

[0262] - The surface on which the recess is formed (which can be the lower surface 111, just as the surface 112, or the surface of layer 12 or the surface of layer 13),

[0263] - The surface defining the bottom of the recess,

[0264] Alternatively, the depth of the recess can vary, that is, it can vary according to one or more positions of the relevant recess. In particular, the height (or depth) of the side or wall defining the contour of the recess can vary and thus is not necessarily constant. In addition, the surface defining the bottom of the recess is not necessarily parallel to the surface on which the recess is formed.

[0265] The above-mentioned side or wall can be at a (constant or variable) inclination angle with respect to, for example, the surface on which the recess is formed and / or with respect to the surface defining the bottom of the recess. In other words, the angle between the following can be any angle, thus enabling any type of design:

[0266] - The direction in which the recess is formed, and

[0267] - The normal to the surface on which it is formed.

[0268] More generally, the area of material ablated or removed at the level of any plane perpendicular to the direction in which the recess is formed and disposed between the following surfaces:

[0269] - The surface on which the recess is formed (which can be the lower surface 111, just as the surface 112, or the surface of layer 12 or the surface of layer 13), and

[0270] - The surface defining the bottom of the recess,

[0271] can be constant or not constant, depending on the relative position of the plane between the surface on which the recess is formed and the surface defining the bottom of the recess. In other words, the area of material ablated and removed at the level of the plane perpendicular to the direction in which the recess is formed and disposed between the surface on which the recess is formed and the surface defining the bottom of the recess can vary according to the direction in which the recess is formed. In addition, the area of material ablated and removed at the level of any plane parallel to the direction in which the recess is formed can be constant or variable. In other words, the area of material ablated and removed at the level of any plane parallel to the direction in which the recess is formed can vary in a direction orthogonal to the direction standard of the formation of the recess.

[0272] The relevant material area removed by ablation can be on the order of millimeters (e.g., between 1 mm 2 and 15 mm 2 ), on the order of micrometers (e.g., between 1 μm 2 and 15 μm 2 ), on the order of nanometers (i.e., any area less than 1 μm 2 ), or the relevant material area removed by ablation can be a surface whose one dimension is on the order of:

[0273] - millimeter (between 0.5 mm and 10 mm (including 0.5 mm and 10 mm), even between 1 mm and 5 mm (including 1 mm and 5 mm)), or

[0274] - micrometer (between 0.5 μm and 200 μm (including 0.5 μm and 200 μm), even between 1 μm and 50 μm (including 1 μm and 50 μm)), or

[0275] - nanometer (between 50 nm and 500 nm (including 50 nm and 500 nm), even between 200 nm and 400 nm (including 200 nm and 400 nm)). In other words, the recess can thus have an area on the order of millimeters or micrometers or nanometers, in particular at the level of the surface defining the bottom of the recess and / or at the level of the surface forming the recess.

[0276] These variations can be combined to produce different optical effects, in particular to produce color hues and gradients.

[0277] In addition, this machining or removal by ablation can be carried out in a pigment added before or after curing.

[0278] The examples described in detail below relate to the production of the following:

[0279] - glass,

[0280] - a two-color outer ring, and

[0281] - a two-color outer ring with metallized recesses.

[0282] The first example relates to the production of a watch glass, in particular made of sapphire and having two shades of red.

[0283] The first step consists in obtaining a watch glass, for example made of sapphire. For example, the lower surface 111 and / or the upper surface 112 is planar.

[0284] The second step consists in forming the decoration (first layer 12). In this step, a red pigment is obtained (prepared in advance, in particular by screen-printing a colored enamel onto a transfer paper). When it is immersed in deionized water, the colored enamel film is separated from the transfer paper. Then this film is applied to the lower surface 111 of the watch glass (the face intended to be located inside the watch case). Then the watch glass is cured in an oven at 800 °C for 15 minutes. The rate of increase in temperature is rapid (about 30 minutes), and cooling is achieved in an equal duration, such that the total heat treatment for achieving enamel vitrification lasts less than one and a half hours.

[0285] The third step consists in forming the decorative layer (second layer 13). In this third step, a white opaque enamel layer is applied to a part of the decorative layer previously deposited during the second step. The decorative layer is, for example, an enamel layer applied by pigment in the same way as the decoration was applied during the second step. This is generally followed by curing the watch glass in an oven at 800 °C for 15 minutes. The rate of increase in temperature is rapid (about 30 minutes), and cooling is achieved in an equal duration, such that the total heat treatment for achieving enamel vitrification lasts less than one and a half hours.

[0286] Then a watch glass with two shades of red is obtained:

[0287] - A first shade of red (translucent red) at the locations where only the red enamel is applied. The appearance is translucent and shiny. Through the glass, one can see through at the locations of this part of the decoration;

[0288] And

[0289] - A second shade of red (opaque red) at the locations where the opaque white enamel decorative layer is deposited on the red enamel. The appearance is red, more saturated and opaque. It is not possible to see through the glass at these locations.

[0290] Thus, various decorations can be proposed that are formed according to the same principle, such as a watch glass that has a delicate translucent or transparent decoration in some locations and a delicate opaque decoration in other locations, these opaque decorations constituting, for example, logos, graduations or hour markers.

[0291] The second example relates to the production of an outer ring disc from a two-color sapphire in red and black.

[0292] In the first step, a sapphire outer ring disc with a mirror-polished surface finish is obtained. Its upper surface 112 (the surface that the user will directly see when the disc is in place on the timepiece) is, for example, dome-shaped. The lower surface 111 (the surface that the user will indirectly (i.e., through the substrate) see when the disc is in place on the timepiece) is, for example, flat.

[0293] In the second step, a decoration is formed by applying a first layer. To this end, pigments are obtained (a pre-prepared black pigment and a red pigment, in particular by screen-printing enamel onto transfer paper) to form sections intended to be black and sections intended to be red. The pigments are immersed in deionized water so that the transfer paper separates from the colored enamel film. These films are then placed on the lower surface 111. The black film is positioned on half of the lower surface of the sapphire disc, and the red film is positioned on the other half of the lower surface of the sapphire disc. Then it is cured in an oven at 800 °C for 15 minutes. The rate of temperature rise is fast (about 30 minutes), and cooling is achieved in an equal duration, such that the complete heat treatment for achieving enamel vitrification lasts less than one and a half hours. Alternatively, a single pigment including a black area and a red area can be used.

[0294] One or more marks can be formed on the substrate to assist in positioning the pigment film on the first surface 111. The one or more marks can advantageously be positioned on the first surface or on a surface adjacent to the first surface. The one or more marks can advantageously be composed of a material that disappears during enamel vitrification.

[0295] In the third step, a decorative layer is formed. To this end, during the second step, an opaque white enamel layer is applied over the entire previously enameled part. The decorative layer is also obtained using pigments and is applied in the same manner as the decoration during the second step. The obtained lower surface 111 seen through the substrate has a first half that is opaque red and a second half that is opaque black.

[0296] Then the outer ring disc with the opaque decoration can be clamped into a steel ring to form the outer ring. The technical part of the outer ring can be highlighted by areas that remain transparent after forming the decoration on the lower surface 111 of the disc.

[0297] The third example relates to the production of a red and black two-color sapphire outer ring disc with metallized recesses.

[0298] The decoration of the disc obtained in the second example above can be continued to obtain the third example including metallized recesses or engravings.

[0299] Use the disc obtained by the procedure described in the second example.

[0300] Then cover the upper surface 112 with a protective resin.

[0301] Thereafter, recesses are formed on the upper surface 112 through the resin, in particular using a femtosecond laser.

[0302] Then a metal (in particular platinum) coating is deposited on the upper surface by PVD (physical vapor deposition).

[0303] Then dissolve the resin layer. As a result, the metal coating remains only at the bottom of the recesses.

[0304] Obtain a sapphire disc with a two-tone appearance, with saturated and opaque colors. The etched markings (constituted by recesses) on the upper surface 112 have a metallic appearance after physical vapor deposition.

[0305] As in the second example, the outer ring disc can then be clamped into a steel ring to form the outer ring. The possible technical parts can be exposed by keeping the areas that remain transparent after forming the decoration on the lower surface.

[0306] Due to the described solution, due to the proposed innovative construction, the advantages of pigment decoration and the advantages of the sapphire substrate can be obtained in a synergistic manner.

[0307] Due to the wide color range of available enamel colors, pigment decoration can obtain aesthetic advantages without design limitations (only the resolution of the pigment must be considered; for example, when produced by screen printing, the resolution is the resolution of the mesh of the selected frame). The enamel deposited by the pigment technique has very good adhesion. However, for this purpose, it is necessary to match the thermal expansion coefficient of the enamel and the thermal expansion coefficient of the substrate. The advantages provided by the enamel are to ensure the possible use of the parts produced over a very wide temperature range, as well as excellent resistance to thermal shock, UV rays, moisture (even in combination with high temperatures), and chemical products. The pigment does not remain on the flat surface. In fact, the film can be deposited on a surface with relief (for example, suitable for a disc with a frustoconical or domed surface). The pigment does not remain on the surface bounded by the sides because the film is a coherent object (different from traditional enamel, which is deposited in a fluid form and therefore requires the provision of sides to keep it in its intended position). Pigment deposition has greater repeatability and automation than traditional glazing using a brush. Therefore, high-quality series production can be obtained.

[0308] Sapphire is the preferred material for producing the substrate 11. In fact, sapphire has excellent scratch resistance due to its very high hardness. For watch part applications, the fact that the upper surface 112 of the part (the surface exposed to possible mechanical erosion) is made of sapphire enables a solution that is at least as good as the current ceramic solutions. In fact, the hardness of sapphire is equal to the hardness of polycrystalline alumina used to produce some parts and greater than the hardness of zirconia used to produce other parts.

[0309] In addition, sapphire has excellent fracture stress. For the production of watch components, the fact that the upper surface 112 of the component is made of sapphire makes it possible to provide a solution that is at least as good as currently known solutions. In fact, on average, the fracture stress of sapphire has a value of approximately 1700 MPa along axis A and approximately 3500 MPa along axis C, which is greater than the fracture stress of zirconia (approximately 1300 MPa), and the fracture stress of zirconia itself is greater than the fracture stress of polycrystalline alumina (approximately 500 MPa).

[0310] In the proposed innovative construction, new advantages are obtained through the combination of sapphire and pigments (the pigments are applied to the surface visible through the substrate, enabling the use of a light-shielding decorative layer):

[0311] - The proposed solution combining sapphire and enamel decoration is completely inorganic and thus cannot be degraded by UV rays, cannot be degraded over a very wide temperature range, cannot be degraded by moisture (even in combination with high temperatures), or by chemical products, without having to seal the decoration. In addition, it is wear-resistant.

[0312] - The decoration is at a certain distance from the upper surface 112 of the substrate directly visible to the user (the decoration is below the sapphire), and this arrangement creates an aesthetic and visual effect of depth. This effect can be further enhanced by the geometry of the circular recesses or the domed protrusions on the surface of the substrate directly visible to the user.

[0313] - The design enables the stacking of treatments and effects. For example:

[0314] * Treatments, especially anti-reflection treatments, can be applied to the upper surface 112 of the sapphire, and / or

[0315] * Recesses can be formed on the upper surface 112 and / or the lower surface 111 of the sapphire.

[0316] - Due to the color and position of the colored layer, the aesthetic effect can be selected.

[0317] - The transparency level and aesthetic effect can be changed by adjusting the opacity and color of the decorative layer, and its position can also be changed. For the masking function, an opaque layer can be formed.

[0318] From an industrial perspective, the described solution is very advantageous in the sense that high production quality can be achieved due to the repeatability of the method for producing watch components.

[0319] In particular, the described solution enables the upper surface 112 of the sapphire to be processed after performing the steps of obtaining the substrate, applying the first layer, and applying the second layer. To perform this processing, advantage can be taken of the transparency of the substrate, and thus the processing position of the upper surface 112 can be located with reference to the decoration formed on the lower surface 111. This makes it possible to position the processing on the upper surface by observing / identifying the shape of the decoration. Thus, one or more recesses can be formed on the upper surface 112 at an exact position relative to the enamel decoration previously formed on the lower surface 111 of the watch part, that is to say, the decoration formed by the first enamel layer can be used as a marker, in particular as a machining marker, to form one or more recesses on the upper surface 112. Conversely, an enamel decoration can be formed on the lower surface 111 of the watch part at an exact position relative to the one or more recesses previously formed on the upper surface 112, that is to say, the one or more recesses on the upper surface 112 can be used as a marker to produce the decoration formed by the first layer of enamel.

[0320] The described solution also makes it possible to easily produce many variants of the part. In fact, starting from a series of identical substrates 11 and depending on the choices made in forming the first and second layers, it is finally possible to obtain watch parts with highly variable appearances.

[0321] In summary, in order to obtain decorated, durable, and variable watch parts (with no restrictions on the choice of graphic elements, patterns, shapes, and colors or combinations thereof, with any spatial distribution (that is, no design restrictions)), it is proposed to form a first enamel layer on a partially transparent or transparent substrate, which first enamel layer is intended to be seen through the substrate. The first enamel layer can be formed by transfer, in particular by pigment decal, and / or the first enamel layer can be at least partially covered with a light-blocking second layer, in particular a white light-blocking second layer.

[0322] In this document, "by transfer" means any method capable of transferring (or moving or positioning) the enamel onto the surface to be enameled according to a previously established design (that is, a design that has been constituted before the transfer (or movement or positioning)). This can include:

[0323] - Pad printing, or

[0324] - Direct screen printing, or

[0325] - Programmed deposition by inkjet printing.

[0326] When it comes to moving a film (enamel powder mixed with a polymer) from a transfer paper to the surface to be enameled, the transfer can be a decal, in particular a waterslide decal.

[0327] Thus, the second light-shielding layer is used in combination with the first layer to participate in the formation of the decoration to obtain an inverse use of pigmented glazing. Thus, the user:

[0328] - sees the first layer that may be formed by using pigments through the substrate, and

[0329] - possibly sees the second layer through the substrate and the first layer.

[0330] In the use of pigments according to the prior art, the result is completely different: in fact, the user usually sees the decoration through an uncolored and transparent enamel layer (cover) that covers the decoration to protect it, and the enamel is applied on an opaque substrate.

Claims

1. A clock part (1), wherein it comprises: - a substrate (11) made of at least partially transparent material, and - a first layer (12) of colored enamel applied to the substrate (11) by transfer, in particular by pigment decal applied to the substrate (11).

2. The clock part (1) according to claim 1, wherein the clock part (1) comprises a second decorative layer (13) applied at least partially to the first layer (12) of colored enamel, in particular a light-shielding second decorative layer (13).

3. The clock part (1) according to claim 1 or 2, wherein the substrate is made of inorganic material, such as technical ceramics, quartz, spinel, magnesium aluminate, AlON, YAG, cubic zirconia, mineral glass, polycrystalline alumina, glass-ceramics, single-crystal alumina, and / or the substrate has a real linear light transmittance of greater than 60% or 70% or 80% or 85% for light with a wavelength of 550 nm at least locally.

4. The clock part (1) according to any one of the preceding claims, wherein the substrate has a hardness greater than 800 Hv or 1000 Hv.

5. The clock part (1) according to any one of the preceding claims and claim 2, wherein the second decorative layer is: - an enamel layer, in particular an enamel layer applied by transfer, and / or - a metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD, PLD, and / or - another coating layer, such as a paint layer.

6. The clock part (1) according to any one of the preceding claims, wherein the clock part (1) is an external housing part of a clock (100), for example in particular: - glass, - bottom cover, - outer ring disc, - wristband element, or - middle piece, Or, the clock part (1) is an internal part of a clock (100), for example in particular: - dial, - flange, or - a disc for displaying clock information.

7. The clock part (1) according to any one of the preceding claims, wherein: - the substrate (11) comprises a first surface (111) and a second surface (112), in particular a second surface (112) parallel to or substantially parallel to the first surface (111), - the first layer (12) and / or the second layer (13) are applied to the first surface (111), and - the first surface (111), in particular the first layer and / or the second layer applied to the first surface, can be seen through the second surface (112) and the substrate (11).

8. The clock part (1) according to claim 7, wherein the substrate (11) comprises at least one second recess (15) formed on the second surface (112), in particular at least one second recess (15) formed by laser machining.

9. The clock part (1) according to claim 8, wherein the at least one second recess (15) has a coating, in particular coated with a metal base layer, in particular coated with a metal base layer deposited by PVD, CVD, ALD or PLD.

10. The clock component (1) according to any one of claims 7 to 9, wherein the substrate (11) has an anti-reflection treatment on the second surface (112).

11. The clock component (1) according to any one of the preceding claims and claim 7, wherein the substrate (11) comprises at least one first recess (14) formed on the first surface (111) after applying the first layer and the second layer, in particular at least one first recess (14) formed by laser machining.

12. The clock component (1) according to claim 11, wherein the at least one first recess (14) has a coating, in particular a metal base layer is coated, in particular a metal base layer deposited by PVD, CVD, ALD or PLD.

13. The clock component (1) according to claim 11 or 12, wherein the at least one first recess (14) is such that the material area removed by ablation lies between the following surfaces on a level in a plane perpendicular to the direction in which the at least one first recess is formed: - the surface forming the at least one first recess, in particular the lower surface (111) or the surface of the first layer (12) or the surface of the second layer (13), and - the surface defining the bottom of the at least one first recess, and varies in the direction in which the at least one first recess is formed, and / or the at least one first recess (14) is such that the material area removed by ablation on a level in any plane parallel to the direction in which the at least one first recess is formed varies in a direction standard orthogonal to the direction in which the at least one first recess is formed.

14. The clock component (1) according to any one of claims 11 to 13, wherein the at least one first recess (14) has an area on the millimeter or micron or nanometer scale, in particular on the level of the surface defining the bottom of the recess and / or on the level of the surface forming the recess.

15. A method of manufacturing a clock component (1), the method comprising the following steps: - obtaining a substrate (11) made of at least partially transparent material, and - applying a first layer (12) of colored enamel to the substrate (11) by transfer, in particular applying a first layer (12) of colored enamel to the substrate (11) by pigment decal.

16. The method according to claim 15, wherein the method comprises applying at least partially a second decorative layer (13), in particular a light-shielding second decorative layer (13), to the first layer (12) of colored enamel.

17. The manufacturing method according to claim 16, wherein applying the second layer is: - applying an enamel layer, in particular applying an enamel layer by transfer, in particular applying an enamel layer by pigment decal, and / or - applying a metal base layer, in particular applying a metal base layer by PVD, CVD, ALD, PLD, and / or - applying another coating layer, such as applying a paint layer.

18. The production method according to any one of claims 15 to 17, wherein the production method includes the step of forming at least one first recess (14), in particular at least one first recess (14) formed by laser machining, on the first surface (111) of the substrate (11), and / or the production method includes the step of forming at least one second recess (15), in particular at least one second recess (15) formed by laser machining, on the second surface (112) of the substrate (11).

19. The production method according to claim 18, wherein the step of forming at least one first recess and / or the step of forming at least one second recess is carried out after the step of applying the first enamel layer (12) to the substrate (11), and in the step of forming at least one first recess and / or in the step of forming at least one second recess, the decoration formed by the first enamel layer is used as a mark, in particular as a machining mark.

20. The production method according to any one of claims 18 and 19, wherein the method includes the step of coating the at least one first recess (14) and / or the at least one second recess (15), in particular coating with a metal base layer, in particular a metal base layer deposited by PVD, CVD, ALD or PLD.

21. A timepiece (100) comprising a timepiece component (1) according to any one of claims 1 to 14, in particular a timepiece component (1) according to any one of claims 7 to 14, the timepiece component (1) being arranged such that the first surface (111), in particular the first layer (12) and / or the second layer (13), can be seen by the wearer of the timepiece (100) through the second surface (112) and the substrate (11).

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