Timepiece or jewelry part and method of manufacturing timepiece or jewelry part

Abstract

The invention relates to a timepiece or jewelry part made entirely or partially of a material comprising gold between 9 and 21 carat, the material (1) comprising a matrix (2) of a predetermined color and at least gold particles (3) dispersed in the matrix, the predetermined color matrix is defined by coordinates a *, b * and L * of the predetermined color matrix in the CIE L * a * b * space, the density of the predetermined color matrix being less than or equal to 10 g / cm3, preferably less than or equal to 8 g / cm3. According to the invention, the size of the gold particles (3) is such that, in the plane of the surface of the material under study, the maximum size of the gold particles (3) is less than 60 [mu] m, preferably less than 30 [mu] m, and, in the plane of the surface of the material under study, the minimum size of the gold particles (3) is greater than 1 nm, preferably greater than 10 nm, preferably greater than 200 nm, preferably greater than 0.5 [mu] m, more preferably greater than 1 [mu] m, the gold particles (3) do not have a plasma effect and are uniformly dispersed in the matrix (2), and the amount of gold particles (3) dispersed in the matrix (2) is predetermined such that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material (1), the gold particles (3) are irradiated by the light source under the same irradiation conditions. The material (1) appears such that the color of the material is the same as or close to the predetermined color of the substrate (2), the color of the material being such that in the CIE L * a * b * color space, the color difference [Delta] E * between the color of the material and the color of the substrate is less than 10, preferably less than or equal to 5, preferably less than or equal to 4, more preferably less than or equal to 3. The invention also relates to a method for manufacturing a timepiece or jewelry part as defined above.

Description

Watch or jewelry component and method of manufacturing such watch or jewelry component Technical Field

[0001] The present invention relates to a watch or jewelry component made of a material comprising gold between 9 carats and 21 carats, including the limits of 9 carats and 21 carats, i.e., the material comprising gold by weight between 37.5% and 87.5% (including the limits of 37.5% and 87.5%) relative to the total weight of the material, the material comprising a matrix of a predetermined hue (e.g., a dark hue or a black hue) and comprising at least gold particles dispersed in the matrix.

[0002] The present invention also relates to a method for manufacturing such watch or jewelry components. Background Technology

[0003] In the manufacture of watch or jewelry components, gold alloys are typically used either as a deposited coating or in solid form. Traditionally, these alloys are yellow, red, or gray in color. Watchmakers and jewelers seeking to move beyond the raw color of gold are particularly active in developing gold alloys with different shades, such as dark or black. Such alloys can be obtained by depositing a black layer onto gold material, for example, through electrodeposition of rhodium or ruthenium, or through chemical vapor deposition (CVD) using carbon black. Other methods are based on the plasma effect of gold nanoparticles, using gold nanoparticles coated with at least one layer of a metal oxide (such as silicon, zirconium, or titanium oxide).

[0004] Patent EP 1 887 052 ​​describes an workpiece made of ceramic colored with pigment, the pigment consisting of, for example, gold nanoparticles coated with crystalline silica. The resulting workpiece is in the red range. The amount of pigment in the ceramic is less than 5% by weight. Therefore, this document does not describe any component containing at least 37.5% gold by weight.

[0005] Patent EP 2 369 022 describes a method for manufacturing a solid material comprising at least 12 carats or even 18 carats of gold, formed from gold nanoparticles coated with silica. The color of the gold nanoparticles used is adjusted according to their size, geometry (spherical, cylindrical, and pyramidal), composition, and chemical environment. The solid material is obtained by sintering with heating accompanied by microwave radiation, which allows the specific color of the gold nanoparticles used to be preserved. However, the preparation of a solution of gold nanoparticles that appears bright red, a solution of gold nanoparticles coated with silica that appears purple, and particles obtained after heating and microwave radiation that appear black are described. Therefore, the described method cannot guarantee the preservation of the nanoparticle color and is thus not robust.

[0006] Application EP 3 482 851 describes a method for manufacturing a material comprising at least 18 carats of gold, formed by assembling gold nanoparticles in a titanium dioxide matrix. However, this method is complex because it requires the use of a solvent and heating of the mixture formed in a reactor. Furthermore, due to the significant absorption of light transmission by titanium dioxide or its less-than-ideal optical properties, the penetration depth of light through the material is insufficient to achieve the maximum plasmon effect of the gold nanoparticles, resulting in a material that is not black. Moreover, it specifies that the obtained powder is black in color before the compaction and sintering steps, while after these two steps, the material appears anthracite-like. This alters the initial color of the nanoparticles. Additionally, the mechanical properties of titanium dioxide (e.g., hardness) are not always sufficient to meet the specifications adopted for each component.

[0007] The object of the present invention is to overcome these shortcomings by providing a watch or jewelry component made of a material comprising gold between 9 and 21 carats, having a uniform predetermined hue, particularly a dark or black hue.

[0008] Another object of the present invention is to provide a method for manufacturing watch or jewelry components made of a material including gold between 9 and 21 carats, wherein the method ensures a predetermined hue.

[0009] Another object of the present invention is to provide a method for manufacturing watch or jewelry components made of a material including gold between 9 and 21 carats, the method of which makes it easy to obtain components of gold including a predetermined color (e.g., dark or black, especially jet black). Summary of the Invention

[0010] Therefore, the present invention relates to a watch or jewelry component, which is made wholly or partially of a material comprising gold between 9 and 21 carats, including the extreme values ​​of 9 and 21 carats, the material comprising a predetermined hue matrix and at least comprising gold particles dispersed in the matrix, the predetermined hue matrix being etched by CIE L. * a * b * coordinates a in space * b * and L * The density of the matrix is ​​specified to be less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 .

[0011] According to the present invention, the gold particles are sized such that, in a plane of the surface of the material under study, the maximum size of the gold particles is less than 60 μm, preferably less than 30 μm, and the minimum size of the gold particles in a plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm. The gold particles do not exhibit a plasma effect. The gold particles are uniformly dispersed in a matrix, and the amount of gold particles dispersed in the matrix is ​​predetermined such that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material, under the same illumination conditions, the material appears to have a hue that is the same as or close to the predetermined hue of the matrix. The hue of the material is such that, according to CIE L... * a * b * In a color space, the color difference ΔE between the hue of the material and the hue of the matrix. * Less than 10, preferably less than or equal to 5, more preferably less than or equal to 4, and even more preferably less than or equal to 3.

[0012] Therefore, through optical effects, the same observer placed at least 30 cm away from the surface of the watch or jewelry component according to the invention will perceive, under the same illumination conditions, a watch or jewelry component comprising gold between 9 and 21 carats and having an overall uniform color that is the same as or close to the color of the matrix initially selected.

[0013] For example, in CIE L * a * b * In space, by parameter -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 <a​​* <5、-5 * <5 and L * <30, preferably -5 * <5、-5 * <5 and L * In the case of a matrix with a predetermined black or dark hue as defined in <15, the same observer, placed at least 30 cm away from the surface of the watch part or jewelry part according to the invention, will perceive through optical effects, under the same illumination conditions of the light source, that the watch part or jewelry part comprises gold between 9 and 21 carats and has an overall uniform black or dark hue corresponding to the predetermined hue of the matrix as defined above.

[0014] The present invention also relates to a method for manufacturing watch components or jewelry components, the watch components or jewelry components being wholly or partially made of a material comprising gold between 9 carats and 21 carats, including the extreme values ​​of 9 carats and 21 carats, the method comprising the steps of: a) providing a material intended to form a predetermined hue matrix, the predetermined hue matrix being formed by the predetermined hue matrix in CIE L * a * b * coordinates a in space * b * and L * The density of the predetermined color matrix is ​​specified to be less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 b) Provide at least initial gold particles; c) Combine the initial gold particles with a material intended to form the matrix to obtain a uniform dispersion of the gold particles in a matrix having the predetermined hue; d) Make the watch component wholly or partially from a material in which the size of the gold particles is such that, in a plane of the surface of the material under study, the maximum size of the gold particles is less than 60 μm, preferably less than 30 μm, and the minimum size of the gold particles is greater than 1 nm, preferably greater than 10 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm, the gold particles do not have a plasma effect, and the amount of gold particles dispersed in the matrix is ​​predetermined such that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material, under the same illumination conditions of the light source, the material appears to have a hue that is the same as or close to the predetermined hue of the matrix, the hue of the material being such that, in CIE L… * a * b * In a color space, the color difference ΔE between the hue of the material and the hue of the matrix. * ​​​Less than 10, preferably less than or equal to 5, more preferably less than or equal to 4, and even more preferably less than or equal to 3.

[0015] Advantageously, watch parts can be made by mixing powder of a material intended to form a predetermined hue matrix with gold powder and then sintering, or by mixing particles of a material intended to form a predetermined hue matrix in a gold bath and then cooling.

[0016] This manufacturing method is relatively simple to implement. Attached Figure Description

[0017] Other features and advantages of the invention will become apparent from the following detailed description of various embodiments of the invention provided as non-limiting examples, and with reference to the accompanying drawings, in which: - Figure 1 schematically shows the surface of a material for a watch component or jewelry component according to the invention, as seen by an observer placed less than 10 cm away from the surface of the material, with a predetermined hue of black; - Figure 2 schematically shows the surface of the material for the watch component or jewelry component of Figure 1, as seen by an observer placed more than 30 cm away from the surface of the material; and - Figure 3 schematically shows the steps of the method according to the invention. Detailed Implementation

[0018] This invention relates to a watch or jewelry component made wholly or partially of a material comprising gold ranging from 9 carats to 21 carats, with the limits of 9 carats and 21 carats. For example, such a watch or jewelry component may consist of an oscillating mass, external elements of a watch (e.g., dial, flip cover, appliqué, crown, hands), or jewelry.

[0019] The material of the watch or jewelry component includes a predetermined hue matrix and at least includes gold particles dispersed in the matrix, the predetermined hue matrix being formed by the predetermined hue matrix in CIE L * a * b * coordinates a in space * b * and L * Limited. The density of the material constituting the matrix is ​​less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 Preferably less than or equal to 6 g / cm³ 3 And preferably greater than or equal to 1 g / cm 3 .

[0020] According to the present invention, the gold particles in the material have a size such that, in the plane of the surface of the material under study, the maximum size of the gold particles is less than 60 μm, preferably less than 30 μm, preferably less than 10 μm, preferably less than 5 μm, and the minimum size of the gold particles in the plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 50 nm, preferably greater than 100 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm.

[0021] In this invention, the size or dimension of a particle is referred to as its equivalent diameter, that is, the diameter of a sphere that behaves the same during particle size analysis of the particles (or powder formed from said particles), the particle size distribution (particle size set), and is measured, in particular, by laser particle size measurement according to ISO standard 13320:2009. The particle size indicated in this application corresponds to the D95 percentile, which means that 95% of the particles in the considered particle set are smaller than D95.

[0022] In addition, the gold particles in the materials of watch or jewelry components are evenly dispersed in the matrix, that is, evenly dispersed in the mass block.

[0023] Furthermore, the size of the gold particles and the matrix are selected within the limits indicated above, the gold particles do not exhibit plasma effects, and the amount of gold particles dispersed in the matrix is ​​predetermined during the manufacture of the component, such that the material has the desired fineness and that, through optical effects, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material, under the same illumination conditions, the material appears to have a hue that is the same as or close to the predetermined hue of the matrix, such that the hue of the material is such that, according to CIE L... * a * b * In a color space, the color difference ΔE between the hue of the material and the hue of the matrix itself. * Less than 10, preferably less than or equal to 8, preferably less than or equal to 7, preferably less than or equal to 5, preferably less than or equal to 4, more preferably less than or equal to 3, more preferably less than or equal to 2, more preferably less than or equal to 1.

[0024] CIE L * a * b * Color difference or color deviation ΔE in a color space * Equation (I) defines the measure of the difference between two colors: (1).

[0025] , , The first color to be compared is in CIE L * a * b * Coordinates in color space, and , , The second color to be compared is in CIE L * a * b * Coordinates in a color space.

[0026] CIE L * a * b * These values ​​in the color space , , and , , It was obtained objectively by using a colorimeter under the same illumination conditions of a D65 standardized light source.

[0027] The color difference ΔE between two colors is obtained by objective measurement using a colorimeter. * A value less than 10, preferably less than or equal to 8, preferably less than or equal to 7, preferably less than or equal to 5, preferably less than or equal to 4, more preferably less than or equal to 3, more preferably less than or equal to 2, and more preferably less than or equal to 1, indicates that, for the same observer, under the same illumination conditions from the light source, the two colors are practically or even identical. The colorimeter measures the hue (coordinate a) of a sample made from a material similar to that used in this invention, but comprising only a matrix and without gold particles. * b * and L * ), and the hue (coordinate a) of the sample corresponding to the projection of the sample of the material used in this invention onto a parallel plane at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material. * b * and L * ), and compare the two hues to calculate the color difference ΔE between the two samples. * .

[0028] Therefore, the material of the watch or jewelry component will have the desired fineness, and through optical effects, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material, under the same illumination conditions of the light source, the material will generally appear to have a hue that is the same as or close to the predetermined hue of the matrix, and the gold particles will visually blend into the matrix so that they are indistinguishable to the human eye.

[0029] In this invention, the light source is standardized to type D65 as defined in the CIE category of standard light sources. It is also specified that this invention relates only to optical effects within the visible range of the spectrum (defined as between 400 nm and 790 nm).

[0030] Given that the predetermined hue matrix can also be defined by its spectral composition, this means that the spectral composition of the material of a watch or jewelry component perceived by the same observer under the same illumination conditions of the light source in the visible range of 400 nm to 790 nm is the same as that of the matrix, except that at least a small portion of the wavelength spectrum is greater than 450 nm. More specifically, the spectral composition of the materials of watch or jewelry components, perceived by the same observer under the same illumination conditions of a light source, within the visible range of 400 nm to 790 nm, is such that, for any wavelength λ1 less than 450 nm, the intensity reflected by the material is no more than twice, preferably no more than 1.5 times, more preferably no more than 1.3 times, greater than the intensity reflected by the matrix at the same wavelength λ1; and for any wavelength λ2 greater than 450 nm, the intensity reflected by the material is no more than twice or equal to twice the intensity reflected by the matrix at the same wavelength λ2, preferably 1.5 times or equal to 1.5 times the intensity reflected by the matrix at the same wavelength λ2, more preferably 1.3 times or equal to 1.3 times the intensity reflected by the matrix at the same wavelength λ2, and no more than 30 times, preferably no more than 20 times, more preferably no more than 10 times, greater than the intensity reflected solely by the matrix at the same wavelength λ2.

[0031] For a wavelength λ2 between 500 nm and 650 nm, preferably, the intensity reflected by the material of the watch or jewelry component is no more than 30 times greater than the intensity reflected by the matrix alone at the wavelength λ2, preferably no more than 20 times, and more preferably no more than 10 times.

[0032] For wavelengths greater than 450 nm, preferably for all wavelengths greater than 450 nm, preferably, the percentage of intensity reflected by the material of the watch or jewelry component differs from the percentage of intensity reflected only by the matrix at said wavelength λ2 by less than 10%, preferably less than 5%, more preferably less than 1%.

[0033] The matrix can have any hue, and the size and number of gold particles without plasma effects, as well as the density of the matrix material, are selected and adjusted by those skilled in the art within the limits indicated above to obtain, through optical effects, the desired fineness of the material as defined above and the pursued ΔE. * Value. Gold particles in CIE L * a * b *In space by parameter L * =86.931, a * =-1.924, b * =87.132 is used as a limit. This means that in CIE L * a * b * In the color space, the color difference ΔE between the hue of the matrix itself and the hue of the gold particles. * The value can be greater than 15, preferably greater than 20, preferably greater than 50, or even greater than 80, and through optical effects, the hue of the material perceived by the same observer placed at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material, under the same illumination conditions of the light source, makes the color appear in CIEL... * a * b * In a color space, the color difference ΔE between the hue of the material and the hue of the matrix itself. * Less than 10, preferably less than or equal to 8, preferably less than or equal to 7, preferably less than or equal to 5, preferably less than or equal to 4, more preferably less than or equal to 3, more preferably less than or equal to 2, more preferably less than or equal to 1.

[0034] Referring to Figures 1 and 2, an exemplary embodiment of the present invention is described, in which the predetermined hue is a dark hue or a black hue, and the material 1 includes a matrix 2 having the predetermined hue and gold particles 3 dispersed in the matrix 2, where the predetermined hue is a dark hue or a black hue.

[0035] In this invention, dark tone or black tone means in CIE L * a * b * In space, by parameter -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 * <5、-5 * <5 and L * <30, preferably -5 * <5、-5 * <5 and L * <15, more preferably -1 * <1、-1 * <1 and 0≤L * <10, more preferably -1 * <1、-1 * <1 and 0≤L * <6 limited colors. ​​​​​​​​​​

[0036] Advantageously, the predetermined hue matrix 2 is made of a material having a predetermined hue, the material being selected from ceramics, ceramic oxides, polymers, carbon, or mixtures thereof, and the material is selected such that its density is less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 Preferably less than or equal to 6 g / cm³ 3 Preferably greater than 1 g / cm 3 As defined above. Preferably, the material intended to form the predetermined hue matrix has a melting temperature higher than that of gold.

[0037] In the case of an example with a predetermined dark or black hue, preferably, the matrix 2 having the predetermined dark or black hue is made of a material selected from zirconium oxide colored with a black pigment (e.g., carbon), alumina colored with a black pigment (e.g., carbon), silicon carbide, silicon nitride, carbon, or mixtures thereof.

[0038] Preferably, the predetermined hue matrix 2 comprises particles with a size between 20 nm and 30 μm.

[0039] For example, gold particle 3 could be a 24-karat pure gold particle that appears as a standard yellow color.

[0040] According to the present invention, the gold particles 3 are uniformly dispersed in a matrix 2 having a predetermined hue (here, for example, a predetermined dark hue or black hue), and the gold particles 3 have a size such that, in the plane of the surface of the material under study, the maximum size of the gold particles is less than 60 μm, preferably less than 30 μm, preferably less than 20 μm, preferably less than 10 μm, preferably less than 5 μm, and the minimum size of the gold particles in the plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 50 nm, preferably greater than 100 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm, and the gold particles 3 do not have a plasma effect. This means that the equivalent diameter of the gold particles 3 formed in the material 1 is less than 60 μm, preferably less than 30 μm, preferably less than 20 μm, preferably less than 10 μm, preferably less than 5 μm, but greater than 1 nm, preferably greater than 10 nm, preferably greater than 50 nm, preferably greater than 100 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm. For example, if the gold particles in the matrix are spherical, then the diameter in the plane of the surface of the material under study is the diameter of the sphere. If the gold particles have another shape, such as a pyramid, then the maximum surface area of ​​the particles in the plane of the surface of the material under study can be determined.

[0041] Advantageously, in the plane of the surface of the material 1 under study, the maximum size of the gold particles 3 is less than 20 μm, preferably less than 10 μm, and more preferably less than 5 μm. In the plane of the surface of the material 1 under study, the minimum size of the gold particles 3 can be greater than 200 nm, preferably greater than 0.5 μm, and more preferably greater than 1 μm, such that the gold particles 3 formed in the material 1 have a micrometer-scale size and do not exhibit plasmonic effects, thus obtaining the material's hue through optical effects. Alternatively, in the plane of the surface of the material 1 under study, the minimum size of the gold particles 3 is greater than 1 nm and less than 200 nm, but the distance between the particles or for some other reason allows for the absence of plasmonic effects for these gold particles, so that the hue of the material for these gold particles 3 is only related to optical effects.

[0042] Furthermore, the amount of gold particles 3 dispersed in the predetermined hue matrix 2 is predetermined, such that the material includes gold ranging from 9 carats to 21 carats, with the limits of 9 carats and 21 carats, and in particular, gold of 14 carats, 16 carats, 18 carats, or 20 carats.

[0043] Furthermore, compared to a matrix defined by the spectral composition of the matrix in the case of a predetermined dark or black hue, the amount of gold particles 3 dispersed in the matrix 2 is predetermined during the manufacture of the watch or jewelry component, such that light of all wavelengths in the visible spectrum is absorbed by the surface of the material 1, wherein the absorption percentage of the material 1 is greater than 80%, preferably greater than 90%, and the absorption percentage of the material 1 at any wavelength λ1 less than 450 nm is no more than 1%, preferably no more than 0.5%, less than the absorption percentage of the matrix 2 at the same wavelength λ1, and the absorption percentage of the material 1 at any wavelength λ2 greater than 450 nm is at least 0.5%, preferably at least 1%, less than the absorption percentage of the matrix 2 at the same wavelength λ2, and no more than 10%, preferably no more than 5%, less than the absorption percentage of the matrix 2 at the same wavelength λ2, such that for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material 1, under the same illumination conditions of the light source, the material 1 appears to correspond to the predetermined dark or black hue of the material 1 with the predetermined hue of the matrix 2, as shown in Figure 2.

[0044] Therefore, through optical effects, and depending on the resolving power of the observer's eye, the observer no longer perceives the gold particles 3 embedded in the matrix 2 with a predetermined hue (e.g., a dark hue or a black hue), but rather perceives the surface of the material 1 as a uniform surface, where the uniform surface has a dark hue or a black hue corresponding to the predetermined hue of the matrix 2.

[0045] Referring to Figure 3, the present invention relates to a method for manufacturing a watch component or jewelry component as described above, wherein, for example, the watch component or jewelry component has a dark or black hue, and the substrate 2 has a predetermined hue, here dark or black, the method comprising the steps of: a) providing a material intended to form a substrate 2 having a predetermined hue, the substrate 2 being formed by the substrate 2 in CIE L * a * b * coordinates a in space * b * and L * The density of matrix 2 is limited to less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 Preferably less than or equal to 6 g / cm³ 3 Preferably greater than 1 g / cm 3 b) Provide at least initial gold particles; c) Combine the initial gold particles with a material intended to form a matrix 2 having a predetermined hue (e.g., a dark or black hue) to obtain a uniform dispersion of gold particles 3 in the matrix 2 having a predetermined hue (e.g., a dark or black hue); d) Make the watch component wholly or partially from material 1, wherein the size of the gold particles 3 in material 1 is such that, in the plane of the surface of the material under study, the maximum size of the gold particles 3 is less than 60 μm, preferably less than 30 μm, and the minimum size of the gold particles 3 in the plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 50 nm, preferably greater than 100 nm, preferably greater than 200 nm. The gold particles 3 are nm, preferably greater than 0.5 μm, more preferably greater than 1 μm, and do not exhibit plasma effects. The particle size and matrix are selected within the limits indicated above, and the amount of gold particles 3 dispersed in the matrix 2 has been predetermined in step b), such that the material has the desired fineness and that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material, under the same illumination conditions, the material appears to have a hue that is the same as or close to the predetermined hue of the matrix. Here, for example, the material has a dark or black hue corresponding to a predetermined dark or black hue of the matrix 2, and the hue of the material makes it appear as if the material's hue is the same as or close to the predetermined hue of the matrix 2 in CIEL. * a * b * In a color space, the color difference ΔE between the hue of the material and the hue of the matrix itself. * Less than 10, preferably less than or equal to 8, preferably less than or equal to 7, preferably less than or equal to 5, preferably less than or equal to 4, more preferably less than or equal to 3, more preferably less than or equal to 2, more preferably less than or equal to 1.

[0046] In a preferred embodiment, the predetermined hue matrix 2 has an overall uniform dark or black hue, and is formed by the predetermined hue matrix 2 in CIE L. * a * b * coordinates a in space * b * and L * The constraint makes -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 * <5、-5 * <5 and 0≤L * <30, more preferably -5 * <5、-5 * <5 and L * <15.

[0047] Preferably, for example, the initial gold particles provided in step b) are 24-karat pure gold particles, and the size of the 24-karat pure gold particles is, for example, between 1 nm and 1 μm, or for example, between 10 nm and 1 μm. The size of the initial gold particles is selected such that the gold particles 3 formed in the matrix 2 have the desired size, that is, the size of the gold particles 3 is such that, in the plane of the surface of the material under study, the maximum size of the gold particles is less than 60 μm, preferably less than 30 μm, preferably less than 20 μm, preferably less than 10 μm, preferably less than 5 μm, and the minimum size of the gold particles in the plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 50 nm, preferably greater than 100 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm. In practice, the size of the initial gold particles will increase due to the agglomeration of gold particles during the production of the component.

[0048] Gold particles 3 do not exhibit a plasma effect, and gold particles 3 are selected to produce an optical effect together with the matrix. Therefore, as indicated above, the overall uniform hue of the material described above is attributed to an optical effect, and the absence of a plasma effect is due to the size of the gold particles 3 or the spacing of the gold particles, or any other reason that may cause the possible nano-gold particles 3 to not exhibit a plasma effect.

[0049] ​​​​​​In another embodiment, the matrix 2 may include first gold particles and second gold particles as defined above dispersed within the matrix. The first gold particles enable a hue to be obtained substantially through optical effects, and the second gold particles are selected to have a plasmonic effect with a hue that is the same as or close to that of the matrix, thereby enhancing the hue of the matrix and strengthening the optical effects obtained using the first gold particles. The resulting material, comprising the first and second gold particles dispersed within the matrix, possesses the desired fineness and hue through the addition of the first and second gold particles, such that the color difference ΔE * As defined above.

[0050] Due to the selection of pressure, temperature, and time, step d) in the production of the component can control the size of the gold particles and the uniformity of their dispersion in the matrix.

[0051] Different mixtures of different sizes can be used. Preferably, the gold particles provided in step b) have not undergone any prior treatment.

[0052] Advantageously, the amount of initial gold particles provided in step b) is determined by the amount of gold particles 3 in the material, by pre-determining the amount of gold particles 3 by means of prior testing with a colorimeter, in order to establish the correlation between the particle size of the gold particles 3 formed in the material, the desired hue of the material 1, the desired fineness, and the volume ratio between the gold particles 3 and the matrix 2 having a predetermined hue (here, for example, a dark hue or a black hue).

[0053] The material intended to form matrix 2 having a predetermined hue (here, for example, a dark hue or a black hue) can be in solid form or in the form of a gel-liquid powder. The material may include mixtures of powders.

[0054] According to one embodiment, step c) can be performed by a mixture of powder (in solid or colloidal liquid form) of a material intended to form a predetermined hue matrix 2 and gold powder, and step d) can be performed by sintering, including: shaping the obtained mixture to form a dense raw semi-finished product, which is conventionally referred to as a near-net-shape "green," meaning that it is very close to the final shape of the part to be manufactured, possibly by debonding depending on the composition of the material intended to form the matrix 2 with the predetermined hue, and then heating at a temperature near the melting point of the matrix material, for example, heating at 1000°C to 1200°C for zirconium oxide.

[0055] According to another embodiment, step c) can be performed by mixing particles of a material intended to form a matrix with a predetermined hue in a molten gold bath (which are then in solid form). The particles of the material intended to form a matrix with a predetermined hue remain in solid form due to the difference in melting temperature. Step d) is then performed by cooling to achieve overall solidification.

[0056] According to another embodiment, step c) can be performed by permeating liquid gold into a sintered preform, which is made of a material intended to form a predetermined hue matrix.

[0057] Regardless of the embodiment, step d) may include machining and / or finishing processes to obtain the watch or jewelry component.

[0058] Advantageously, material 1 may also include particles of other colors, allowing the hue of the resulting material to be adjusted. For example, the material may include purple particles to mitigate any influence of the yellow hue of gold. Microlens networks, diffraction networks, or frosted glass may also be added to the surface of the material to mix light and obtain a uniformly colored beam. Material 1 can be given a matte or glossy appearance.

[0059] In embodiments where matrix 2 has a predetermined black or dark color, advantageously, the invention enables the production of a watch or jewelry component made wholly or partially of a material comprising gold between 9 and 21 carats, with the limits of 9 and 21 carats, such that, for an observer placed at a distance of at least 30 cm, preferably at least 10 cm, from the surface of the material, the material appears to have an overall uniform color through optical effects, in CIE L. * a * b * In space, the overall uniform color is determined by the overall uniform color in CIE L. * a * b * coordinates a in space * b * and L * The constraint makes, for example, -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 * <5、-5 * <5 and 0≤L * <30, preferably -5 * <5、-5 * <5 and 0≤L * <15, more preferably -1 * <1, -1 * <1 and 0≤L * <10, more preferably -1 * <1、-1 * <1 and 0≤L * <6.​​​​​​​​​​

Claims

1. A watch or jewelry component, said watch or jewelry component being wholly or partially made of a material comprising gold between 9 carats and 21 carats, including the limits of 9 carats and 21 carats, said material (1) comprising a predetermined hue matrix (2) and at least comprising gold particles (3) dispersed in said matrix, said predetermined hue matrix being etched in CIE L * a * b * coordinates a in space * b * and L * The density of the matrix (2) is specified to be less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 Its characteristics are, The size of the gold particles (3) is such that, in the plane of the surface of the material under study, the maximum size of the gold particles (3) is less than 60 μm, preferably less than 30 μm, and the minimum size of the gold particles (3) in the plane of the surface of the material under study is greater than 1 nm, preferably greater than 10 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm. The gold particles (3) do not have a plasma effect because the gold particles (3) are uniformly dispersed in the matrix (2), and the amount of gold particles (3) dispersed in the matrix (2) is predetermined, such that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material (1), under the same illumination conditions of the light source, the material (1) appears to have a hue that is the same as or close to the predetermined hue of the matrix (2), and the hue of the material makes it appear as if the material's hue is the same as or close to the predetermined hue of the matrix (2). * a * b * In the color space, the color difference ΔE between the hue of the material (1) and the hue of the matrix (2) * Less than 10, preferably less than or equal to 5, more preferably less than or equal to 4, and even more preferably less than or equal to 3.

2. The watch component or jewelry component according to claim 1, characterized in that, The predetermined hue matrix (2) is dark or black, and the predetermined hue matrix is ​​used in the CIE L * a * b * coordinates a in space * b * and L * The constraint makes -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 * <5、-5 * <5 and 0≤L * <30, more preferably -5 * <5、-5 * <5 and L * <15.​​​​​​ 3. A watch component or jewelry component according to any one of the preceding claims, characterized in that, In the plane of the surface of the material under study, the maximum size of the gold particles (3) is less than 20 μm, preferably less than 10 μm, and preferably less than 5 μm.

4. A watch component or jewelry component according to any one of the preceding claims, characterized in that, The predetermined hue matrix (2) is made of a material having a predetermined hue, the material being selected from ceramics, ceramic oxides, polymers, carbon, or mixtures thereof.

5. The watch component or jewelry component according to claim 4, characterized in that, The matrix (2) has a predetermined dark or black hue and is made of a material selected from zirconium oxide colored with a black hue pigment, aluminum oxide colored with a black hue pigment, silicon carbide, silicon nitride, carbon, or mixtures thereof.

6. A watch component or jewelry component according to any one of the preceding claims, characterized in that, The predetermined hue matrix (2) comprises particles with a size between 20 nm and 30 μm.

7. A watch component or jewelry component according to any one of the preceding claims, characterized in that, The watch or jewelry component consists of an oscillating mass, external components of the watch, and jewelry.

8. A method for manufacturing a watch component or jewelry component, said watch component or jewelry component being a watch component or jewelry component according to any one of claims 1 to 7, characterized in that, The method includes the following steps: a) providing a material intended to form a predetermined hue matrix (2), the predetermined hue matrix being formed by the predetermined hue matrix in the CIE L * a * b * coordinates a in space * b * and L * The density of the predetermined hue matrix is ​​specified to be less than or equal to 10 g / cm³. 3 Preferably less than or equal to 8 g / cm³ 3 b) Provide at least initial gold particles; c) Combine the material intended to form the matrix (2) with the initial gold particles to obtain uniform dispersion of gold particles (3) in the matrix (2) having the predetermined hue; d) Make the watch or jewelry component wholly or partially from the material (1), wherein the size of the gold particles (3) of the component is such that, in the plane of the surface of the material under study, the maximum size of the gold particles (3) is less than 60 μm, preferably less than 30 μm, and in the plane of the surface of the material under study, the gold particles (3) are... The minimum size of the gold particles (3) is greater than 1 nm, preferably greater than 10 nm, preferably greater than 200 nm, preferably greater than 0.5 μm, more preferably greater than 1 μm. The gold particles (3) do not have a plasma effect, and the amount of gold particles (3) dispersed in the matrix (2) is predetermined such that, for the same observer placed at a distance of at least 30 cm, preferably at least 10 cm from the surface of the material, under the same illumination conditions of the light source, the material appears to have a hue that is the same as or close to the predetermined hue of the matrix. The hue of the material makes the CIE L * a * b * In the color space, the color difference ΔE between the hue of the material (1) and the hue of the matrix (2) * Less than 10, preferably less than or equal to 5, more preferably less than or equal to 4, and even more preferably less than or equal to 3.

9. The method for manufacturing watch parts or jewelry parts according to claim 8, characterized in that, The predetermined hue matrix (2) is dark or black, and the predetermined hue matrix is ​​used in the CIE L * a * b * coordinates a in space * b * and L * The constraint makes -10 * <10、-10 * <10 and 0≤L * <50, preferably -5 * <5、-5 * <5 and 0≤L * <30, more preferably -5 * <5、-5 * <5 and L * <15.​​​​​​ 10. The method for manufacturing a watch or jewelry component according to any one of claims 8 and 9, characterized in that, The amount of gold particles (3) is predetermined by means of prior testing with a colorimeter to establish the correlation between the particle size of the gold particles (3), the desired hue of the material (1), and the volume ratio between the gold particles (3) and the predetermined hue matrix (2).

11. The method for manufacturing a watch or jewelry component according to any one of claims 8 to 10, characterized in that, Step c) is performed by a mixture of powder of the material intended to form the predetermined hue matrix (2) and gold powder, and step d is performed by sintering.

12. The method for manufacturing a watch or jewelry component according to any one of claims 8 to 10, characterized in that, Step c) is performed by mixing particles of the material intended to form the predetermined hue matrix (2) in a gold bath, and step d is performed by cooling.

13. The method for manufacturing a watch or jewelry component according to any one of claims 8 to 10, characterized in that, Step c) is performed by permeating liquid gold into a sintered preform made of the material intended to form the predetermined hue matrix (2).

14. The method for manufacturing a watch or jewelry component according to any one of claims 8 to 13, characterized in that, Step d) includes machining and / or finishing processes to obtain the watch or jewelry component.

Images