CH716628A2 - Clockwork element with photoluminescent decoration. - Google Patents

Abstract

The invention relates to a timepiece element comprising a substrate (6) and at least one first decorative element (1) comprising at least one first photoluminescent material intended to give a phosphorescent appearance. The timepiece element comprises a second decorative element (3) comprising at least a second material, said second material being metallic, intended to give a metallic appearance, or variochromic, intended to give a color varying under the effect of a stimulus, said first decor element (1) and said second decor element (3) being arranged relative to each other on the substrate (6) to form a decor of metallic appearance or of a color varying under the effect of a stimulus when said timepiece element is exposed to light and of phosphorescent appearance when said timepiece element is in the dark. The present invention also relates to a timepiece comprising such a timepiece element.

Description

Description

Field of the invention

[0001] The invention relates to a timepiece element comprising a substrate and at least one first decorative element comprising at least one first photoluminescent material intended to give a phosphorescent appearance when the element is placed in the dark. The present invention also relates to a timepiece comprising such an element.

Background of the invention

[0002] For example, the use of such a photoluminescent material is known to produce coatings intended to cover the hands or the indexes of a watch, so that the said hands or the said indexes are luminous and appear in the dark.

[0003] Patent CH 697 210 describes a dial comprising a semi-transparent layer, the rear face of which comprises cavities filled with phosphorescent pigments which make it possible to reveal under the semi-transparent layer a decor visible in the dark.

[0004] However, even if the decorations comprising phosphorescent pigments used on a timepiece element are supposed not to be perceptible when the decorated element is exposed to daylight, these decorations nevertheless appear, in particular for an eye knowledgeable professional. The phosphorescent decorations which show through in daylight therefore harm the aesthetics of the timepiece, which is not acceptable, in particular for high-end timepieces.

Summary of the invention

[0005] The object of the present invention is to remedy these drawbacks by proposing a timepiece element comprising a photoluminescent material intended to give a phosphorescent appearance in the dark, said photoluminescent material being masked when the element is exposed to light. , in order to improve its aesthetic appearance.

[0006] To this end, the invention relates to a timepiece element comprising a substrate and at least one first decorative element comprising at least one first photoluminescent material intended to give a phosphorescent appearance.

[0007] According to the invention, said timepiece element comprises a second decorative element comprising at least one second material, said second material being metallic, intended to give a metallic appearance, or variochromic, intended to give a color varying under the effect of a Stimulus, said first element of decor and said second element of decor being arranged one with respect to the other on the Substrate to form a decor of metallic appearance or of a color varying under the effect of a Stimulus when said element is exposed to light and of phosphorescent appearance when said element is in the dark.

[0008] Thus, when the timepiece element according to the invention is exposed to light, the first photoluminescent material deposited on said element disappears in favor of a metallic appearance provided by the second material.

[0009] Consequently, the timepiece element exposed to the light presents an improved aesthetic appearance, the first photoluminescent material of unsightly appearance then being masked, while presenting a beautiful phosphorescent appearance in the dark.

The present invention also relates to a timepiece comprising such an element.

Brief description of the drawings

[0011] Other characteristics and advantages of the invention will appear more clearly on reading the following description of different embodiments of the invention, given by way of simple illustrative and non-limiting examples, and the appended figures, among which:

- Figures 1 to 3 are schematic sectional views of different embodiments of a first embodiment of a timepiece component according to the present invention; And

- Figures 4 to 6 are schematic sectional views of different embodiments of a second variant of embodiment of a timepiece according to the present invention.

Detailed description of preferred embodiments

[0012] The present invention relates to a timepiece element comprising a substrate and at least one first decorative element comprising at least one first photoluminescent material intended to give a phosphorescent appearance in the dark.

[0013] Such a horological element can be a dial, a hand, an index, a bezel, a crystal, on the dial side or on the back side, a watch case, etc.

[0014] The substrate can be opaque or semi-transparent, or even transparent. An opaque Substrate may for example be metallic. It can be made of brass, based on gold, yellow or white, or silver, or any other suitable metal or alloy, precious or not.

[0015] The semi-transparent and transparent Substrates can be glass, sapphire crystal, an acrylic resin or any other suitable resin.

[0016] In accordance with the present invention, the timepiece element comprises a second decorative element comprising at least one second material, said second material being metallic, intended to give a metallic, mother-of-pearl appearance or intended to give a mother-of-pearl effect ( glass particles coated with an interferential) or variochromic layer, intended to give a color varying under the effect of a Stimulus, said first element of decor and said second element of decor being arranged one with respect to the other on the substrate to forming a decor of metallic appearance or of a color varying under the effect of a Stimulus when said element is exposed to light and of phosphorescent appearance when said element is in the dark.

[0017] In a preferred way, the first material consists of photoluminescent pigments, preferably of the SrAl2O4:Eu2+,Dy3+,B3+ or MAI2Si2O8:Eu2+ (M=Ba,Sr,Ca) type.

[0018] In general, the mass content of pigments in the first decorative element can be between 1% and 70%, with at 1% a transparency of the layer of the first decorative element, a low light intensity at t=5mn of the order of 10 mCd/m2 measured according to ISO 17514, and at 70% opacity of the layer of the first decorative element, a luminous intensity of the order of 500mCd/m2 at t=5mn measured according to ISO 17514 Ideally, the mass content of pigment is 50% to achieve a compromise between a good surface condition of the first decorative element and the desired light intensity.

In the present description, the term "metallic material" means an at least partially metallic material which may include non-metallic particles and metallic particles as well as an entirely metallic material.

According to a first variant of the invention, the second material of the second decorative element is present in the form of particles dispersed in the second binder.

According to a first embodiment of the invention shown in Figure 1, the decor is two-layer, in the form of a first layer at least semi-transparent, or even transparent, constituting the first decorative element 1 and comprising a first binder in which are dispersed, as first material, photoluminescent pigments 2, and a second layer constituting the second decorative element 3 and comprising a second binder in which are dispersed, as second material, metallic or metallized film particles 4, or nacreous or variochromic particles, said second layer 3 being placed between the substrate 6 and the first layer 1 intended to be as close as possible to a user.

The first layer semi-transparent or transparent to the visible spectrum constituting the first element of decor1 preferably has a thickness between 0.1 mm and 2 mm.

In the particular case of the first embodiment in which the first layer is semi-transparent or transparent, said first layer comprises between 1% and 10% by weight of photoluminescent pigments as defined above.

The second layer constituting the second decorative element 3 preferably has a thickness <100mu

[0025] In the second layer 3, the particles are chosen in order to reflect the light advantageously to make the phosphorescent particles undetectable to the eye. These are either metallic or metallized, film-coating particles 4, which create a mirror effect for optimum reflection of light. They are advantageously made up of thin metal strips with a particle size preferably between 10 μm and 500 μm, and (for example aluminum, bronze, gold, silver) or of inorganic particles (aluminum oxide, silicon dioxide and borosilicates) metallized under vacuum (for example by PVD, the various layers deposited by PVD being able to advantageously make it possible to create interferential colors giving iridescent or pearly aspects).

[0026] The variochromic particles consist of at least pigments of the photochromic type or of pigments of the thermochromic type such as nanoparticles with a spin transition effect.

The at least semi-transparent first layer constituting the first decorative element 1 based on photoluminescent pigments 2 and the second layer constituting the second decorative element 3 based on metallic or variochromic particles 4 are superimposed, the first layer 1 being designed to be closer to the user. Thus, the decor formed by the superposition of the first and second decor elements 1, 3 has a metallic appearance or a color varying under the effect of a Stimulus linked to the variochromic material, given by the second decor element 3 appearing under the first decor element 1 transparent when the clockwork element is exposed to light, and the decor has a phosphorescent appearance given by the first decor element 1 positioned as close as possible to the user, when the clockwork element is in darkness.

According to a second embodiment of the invention shown in Figure 2, the decor is two-layer, in the form of a first layer constituting the first decorative element 1 and comprising a first binder in which are dispersed,

as first material, photoluminescent pigments 2 as defined above, and a second transparent layer constituting the second decorative element 3 and comprising a second binder in which are dispersed, as second material, metallic or metallized particles 4 not films or variochromic particles, said first layer 1 being placed between the substrate 6 and the second layer 3 intended to be at most one user.

The first layer constituting the first decorative element 1 preferably has a thickness of between 0.1 mm and 2 mm. In this embodiment, the first layer is not necessarily transparent or semi-transparent.

[0030] The second transparent layer constituting the second decorative element 3 preferably has a thickness of <100mu

[0031] The non-film-forming metallic or metallized particles 4 are, for example, the metallized particles described above for the first embodiment, but for which, for example, an unsaturated fatty acid has been used during the grinding of the particles in order to modify their tension of surface. This also makes it possible to better distribute the particles in the layer and to improve the resistance to abrasion.

In the particular case of the second embodiment according to which the second layer 3 is transparent, said second transparent layer comprises less than 5% by weight of metallized particles in order to obtain this transparency, the percentage being substantially identical for the variochromic particles .

The first layer constituting the first decorative element 1 based on photoluminescent pigments 2 and the second transparent layer constituting the second decorative element 3 based on metallic or variochromic particles 4 are superimposed, the second layer 3 being intended to be closer to the user. Thus, the decor formed by the superimposition of the first and second decor elements 1,3 presents a metallic appearance or a color varying under the effect of a Stimulus linked to the variochromic material, given by the second decor element 3 positioned at most close to the user when the clockwork element is exposed to light, and the decor has a phosphorescent appearance given by the first decor element 1 appearing under the second decor element 3 transparent, when the clockwork element is in darkness.

[0034] According to a third embodiment of the invention shown in Figure 3, the decor is single layer, intended to be closer to a user, and form a third layer 8 deposited on the substrate 6 on the of the user to be as close as possible to the user, and comprising a third binder in which are dispersed metallic or metallized particles 4 or variochromic particles forming the second decorative element 3 and coated with photoluminescent pigments 2 forming the first element of decor 1.

For this, use is preferably made of metallic or metallized or nacreous particles 4 or variochromic particles of the type defined above, with a particle size between 100 μm and 500 μm, and preferably between 100 μm and 200 μm. The photoluminescent pigments 2 of the type defined above preferably have a size of less than 10 μm. A dispersion of photoluminescent pigments 2 comprising by weight 5 to 30% of photoluminescent pigments in a liquid polymer/solvent matrix is produced beforehand. Different methods are then possible:

- the dispersion of photoluminescent pigments formed is directly sprayed on the metallic, metallized or variochromic particles which are spread on a plate, then dried. The whole is then ground by cryogenic grinding so that any particles stuck together can be separated.

- the metallic, metallized or variochromic particles are mixed in the dispersion of photoluminescent pigments and then the mixture obtained is introduced into an atomizer making it possible to quickly dry the photoluminescent pigments around the metallic, metallized or variochromic particles. The drying can also be carried out in tray dryers ("tray drying") or by fluidized bed drying ("fluid bed drying"), then the whole is ground again by cryogenic grinding. The particles obtained are then dispersed in the third binder.

[0036] Another alternative requires the following preparation of pigments with metallic or pearl effects. These are coated with a thin and transparent pre-polymer film (between 20-50 microns) by a bath treatment (mixture of 80% solvent, 15% monomers, 2% hardeners and 3% additives ). The treated pigments are then mixed by friction in a ball mill with a dispersion of phosphorescent pigments.

[0037] The pigments resulting from this process are then treated to finalize the Polymerization (thermal curing).

The third transparent layer constituting the decor preferably has a thickness of between 10 μm and 100 μm.

Thus, the decor formed by said third layer has a metallic appearance or a color varying under the effect of a Stimulus linked to the variochromic material, given by the metallic, metallized or variochromic particles 4 appearing under the coating of photoluminescent pigments 2 in the third transparent layer 8 when the timepiece element is exposed to light, and the decor has a phosphorescent appearance given by the coating of photoluminescent pigments 2 formed around the metallic, metallic or variochromic particles 4, when the element of watchmaking is in the dark.

The first, second and third binders used in the first, second and third layers defined above are chosen according to the method of application of the corresponding layer and the transparency that the layer must present.

[0041] In particular, when one of the first or second layers must be at least semi-transparent, or even transparent, the binder and any additives present in the layer are selected to be as transparent as possible to UV and visible radiation. For example, an acrylate binder may be chosen.

The first, second and third layer comprising the associated particles dispersed in the binder can be deposited on the Substrate by spraying or dipping if the entire Substrate must be coated, or by screen printing if a pattern must be produced, or by pad printing. for example if the Substrate has a complex surface.

[0043] According to a second variant of the invention, the substrate is at least semi-transparent, or even transparent, and the second material of the second decorative element is present in the form of a metal film added by gluing for example or formed by vapor phase deposition, such as PVD or CVD. A metallic film with a lacquer is also possible

The metal film is typically made of stainless steel, aluminum, aluminized PET or covered with a gold PVD layer.

[0045] According to one embodiment of the invention represented in FIG. 4, the substrate 6 is at least semi-transparent, or even transparent, and is intended to be on the side of a user. In addition, the decor is formed of a first at least semi-transparent layer constituting the first decor element 1 and comprising a first binder in which are dispersed, as first material, photoluminescent pigments 2, and of a second layer constituting the second decorative element 3 and constituted by a metal film of the type described in connection with the second variant, said first layer 1 being placed between the substrate 6 and the second layer 3, so that the first transparent layer 1 is intended to be closer to the user than the second layer 3.

[0046] In addition, the second decorative element 3 is preferably sized to substantially overlap the surface covered by said first decorative element 1.

[0047] The first semi-transparent or transparent layer constituting the first decorative element 1 presents depreference a thickness between 0.1mm and 2mm. It comprises between 1% and 10% by weight of photoluminescent pigments as detailed above in order to be semi-transparent or transparent.

The at least semi-transparent first layer constituting the first decorative element 1 based on photoluminescent pigments 2 and the second layer constituting the second decorative element 3 based on metallic or variochromic particles 4 are superposed, the first layer 1 being intended to be closer to the user than the second layer 3. Thus, the decor formed by the superposition of the first and second decor elements 1, 3 presents a metallic appearance or a color varying under the effect of a Stimulus in variochromic material, given by the second decor element 3 appearing under the first decor element 1 transparent when the clockwork element is exposed to light, and the decor has a phosphorescent appearance given by the first decor element 1 positioned closest to the user, when the clockwork element is in the dark.

Advantageously, the Substrate 6 comprises at least one lodge 10 engraved in the Substrate, for example by laser, said lodge 10 comprising at least the first decorative element 1.

Advantageously, the film constituting the second decorative element 3 is deposited by vapor phase deposition (CVD or PVD) on the surface 11 of the first decorative element 1 which opens out from the compartment 10, and possibly onto a peripheral zone 12 of Substrate 6. The thickness of the metal foil is typically between 50µm to 100µm.

[0051] According to another embodiment of the invention represented in FIG. 5, the substrate 6 is at least semi-transparent, or even transparent, and is intended to be on the side of a user. In addition, the decor is formed of a first layer constituting the first decor element 1 and comprising a first binder in which are dispersed, as first material, photoluminescent pigments 2, and of a second layer constituting the second decor element 3 and constituted by a metal film of the type described in connection with the second variant having perforations 14 perpendicular to the substrate 6, said second layer 3 being placed between the substrate 6 and the first layer 1, so that the second layer 3 with the perforations is intended to be closer to the user than the first layer 1.

The perforations with a diameter of 100 μm to 200 μm 14 in the metallic or variochromic film are preferably produced by laser after the deposition of the metallic or variochromic film, for example by vapor phase deposition (CVD or PVD) on the Substrate 6. The thickness of the metal sheet is typically between 50µm to 100µm. In addition, the second decorative element 3 is preferably sized to substantially overlap the surface covered by said first decorative element 1.

Advantageously, the substrate 6 comprises at least one compartment 10 engraved in the substrate, for example by laser, at the bottom of which is deposited the perforated metal or variochromic film constituting the second decorative element 3, said compartment being filled with the first layer constituting the first decorative element 1.

Claims (14)

[0054] Advantageously, in particular if the first decorative element 1 occupies on the Substrate a surface greater than that occupied by the second decorative element 1, the first layer constituting the first decorative element is preferably semi-transparent, even transparent , as detailed above. The first layer constituting the first decorative element 1 based on photoluminescent pigments 2 and the second layer constituting the second decorative element 3 based on metallic or variochromic particles 4 are superimposed, the second layer 3 being intended to be more closer to the user than the first layer 1. Thus, the decor formed by the superposition of the first and second decorative elements 1, 3 presents a metallic appearance or a color varying under the effect of a Stimulus linked to the variochromic material, given by the second decorative element 3 positioned closest to the user when the timepiece element is exposed to light, and the decor has a phosphorescent appearance given by the first decorative element 1 appearing through the perforations 14 of the second decorative element 3, when the clockwork element is in the dark. [0056] According to another embodiment of the invention represented in FIG. 6, the substrate 6 is at least semi-transparent, or even transparent, and is intended to be on the side of a user. In addition, the decor is formed of a first at least semi-transparent layer constituting the first decor element 1 and comprising a first binder in which are dispersed, as first material, photoluminescent pigments 2, and of a second layer constituting the second decorative element 3 and constituted by a metal film of the type described in connection with the second variant, said second layer 3 being placed on substrate 6 on the user's side, said first layer 1 being deposited on substrate 6 , on the side opposite to the second layer 3, the surface occupied by the second decorative element on the Substrate 6 having dimensions smaller than the dimensions of the surface of the first decorative element 1 in order to be able to create a phosphorescent halo around the second decorative element. decor 3 when the clock element is in the dark. [0057] Advantageously, the substrate 6 comprises at least one recess 10 etched into the substrate, for example by laser, opening onto the face opposite the second decorative element 3, and filled with the first layer constituting the first element of decor 1. Advantageously, the film constituting the second decorative element 3 is deposited by vapor phase deposition (CVD or PVD) on the surface of the substrate 6 to be closer to the user. The first layer constituting the first decorative element 1 based on photoluminescent pigments 2 and the second layer constituting the second decorative element 3 based on metallic or variochromic particles 4 are superimposed, the second layer 3 being intended to be more closer to the user than the first layer 1. Thus, the decor formed by the superposition of the first and second decorative elements 1, 3 presents a metallic appearance or a color varying under the effect of a Stimulus linked to the variochromic material, given by the second decor element 3 positioned as close as possible to the user when the timepiece element is exposed to light, and the decor has a phosphorescent halo given by the first decor element 1 appearing at the periphery of the second decor element 3, when the clockwork element is in the dark. Claims 1. Clockwork element comprising a substrate (6) and at least one first decorative element (1) comprising at least one first photoluminescent material intended to give a phosphorescent appearance, characterized in that it comprises a second decorative element ( 3) comprising at least one second material, said second material being metallic, intended to give a metallic appearance, or variochromic, intended to give a color varying under the effect of a Stimulus, said first decorative element (1) and said second decor element (3) being arranged one with respect to the other on the substrate (6) to form a decor of metallic appearance or of a color varying under the effect of a Stimulus when said clockwork element is exposed to light and has a phosphorescent appearance when said timepiece element is in the dark. 2. Element according to claim 1, characterized in that the decor is two-layered, in the form of a first at least semi-transparent layer constituting the first decorative element (1) and comprising a first binder in which are dispersed, as first material, photoluminescent pigments (2), and a second layer constituting the second decorative element (3) and comprising a second binder in which are dispersed, as second material, metallic or metallized film particles (4) or variochromic particles, said second layer being placed between the substrate (6) and the first layer intended to be as close as possible to a user. 3. Element according to claim 2, characterized in that the first transparent layer comprises between 1% and 10% by weight of photoluminescent pigments (2). 4. Element according to claim 1, characterized in that the decor is two-layered, in the form of a first layer constituting the first decorative element (1) and comprising a first binder in which are dispersed, as first material, photoluminescent pigments ( 2), and a second transparent layer constituting the second decorative element (3) and comprising a second binder in which are dispersed, as second material, non-filming metallic or metallized particles (4) or variochromic particles, said first layer being arranged between the substrate (6) and the second layer intended to be as close as possible to a user. 5. Element according to claim 4, characterized in that the second transparent layer comprises less than 5% by weight of metallized particles or less than 0.5% by weight of variochromic particles in order to maintain semi-transparency 6. Element according to claim 1, characterized in that the decor is single-layer, intended to be as close as possible to a user, and forms a third layer (8) comprising a third binder in which particles (4 ) metallic or metallized or pearly/iridescent or variochromic particles forming the second decorative element (3) and coated with photoluminescent pigments (2) forming the first decorative element (1). 7. Element according to one of the preceding claims, characterized in that the substrate (6) is opaque or at least semi-transparent. 8. Element according to claim 1, characterized in that the Substrate (6) is at least semi-transparent and intended to be on the side of a user, and in that the decor is formed of a first layer at least semi-transparent transparent constituting the first decorative element (1) and comprising a first binder in which are dispersed, as first material, photoluminescent pigments (2), and a second layer constituting the second decorative element (3) and constituted by a film metallic or mother-of-pearl/iridescent or variochromic, said first layer being placed between the substrate (6) and the second layer in order to be able to be closer to a user than the second layer. 9. Element according to claim 1, characterized in that the substrate (6) is at least semi-transparent and intended to be on the side of a user, and in that the decor is formed of a first layer constituting the first element. of decor (1) and comprising a first binder in which are dispersed, as a first material, photoluminescent pigments (2), and a second layer constituting the second decor element (3) and consisting of a metallic or mother-of-pearl film/ iridescent or variochromic having perforations (14) perpendicular to the substrate (6), said second layer being arranged between the substrate (6) and the first layer to be able to be closer to a user than the first layer. 10. Element according to claim 1, characterized in that the substrate (6) is at least semi-transparent and intended to be on the side of a user, and in that the decor is formed of a first layer at least semi-transparent. transparent constituting the first decorative element (1) and comprising a first binder in which are dispersed, as first material, photoluminescent pigments (2), and a second layer constituting the second decorative element (3) and constituted by a film metallic or mother-of-pearl/iridescent or variochromic, said second layer being placed on the substrate (6) on the user's side, said first layer being deposited on the substrate, on the side opposite the second layer, the second decorative element (3 ) having dimensions smaller than the dimensions of the first decorative element (1) in order to be able to create a phosphorescent halo around the second decorative element (3). 11. Element according to one of claims 8 to 10, characterized in that the metal film is an added metal plate or a metal layer deposited by vapor phase deposition. 12. Element according to one of the preceding claims, characterized in that the substrate (6) comprises at least one compartment (10) comprising at least the first decorative element (1). 13. Element according to one of the preceding claims, characterized in that the variochromic material consists of at least one pigment of the photochromic or thermochromic type. 14. Timepiece comprising an element according to one of claims 1 to 13.