CH718184A2 - Process for printing a functional element on a watch component. - Google Patents

Abstract

The invention relates to a method for printing a functional element (2) on a surface (5) of a receiving zone (3) of a timepiece component, for example a balance wheel, of a timepiece comprising the following steps: - preparation of a solution comprising a material constituting said functional element (2), said preparation step comprising a sub-step of defining specific properties of the solution according to preparation criteria, said properties being relative viscosity and surface tension of that solution and preparation criteria including: • at least one structural modification feature of the horological component; • at least one characteristic of construction of the functional element (2) on said receiving zone (3), • at least one structural characteristic of the material, and • at least one characteristic of said receiving zone (3) of the component, – deposit (34) of said prepared solution on the surface (5) of the receiving zone.

Description

Technical field and state of the art

[0001] The invention relates to a method for printing a functional element on a surface of a receiving zone of a timepiece component of a timepiece as well as to such a timepiece component and to this timepiece.

Background of the invention

[0002] Various prior art processes are known providing for the application of material to a component of a timepiece, in particular when these processes are intended to participate in the adjustment of the rate of a watch movement by the adjustment of the inertia of a component such as a balance wheel of a balance-spring resonator of such a movement.

[0003] In this context, these methods conventionally provide initially for the determination of a correction value to be applied to the inertia of the balance to obtain a desired rate of this movement, said value being determined from the establishment a measure of the rate of the movement of the timepiece. And in a second step, they provide for the implementation of an addition of material by projection of this material on the balance in order to adjust the inertia of this balance according to the determined correction value.

[0004] However, one of the major drawbacks of such methods is linked to the fact that such addition of material by projection often generates splashes, resulting in particular from the impact of this material on the balance, said splashes being likely to spread and contaminate the watch movement and thus cause a malfunction of this movement.

Summary of the invention

[0005] An object of the invention is therefore to propose a method which makes it possible to apply a functional element in a precise and targeted manner to a defined receiving zone of a watch component, the component possibly being a balance wheel in one example.

Another object of the invention is thus to offer the possibility of being able to adjust a timepiece comprising a resonator equipped with such a balance wheel.

Another object of the invention is to print a functional element consisting of a controlled quantity of material on the receiving zone of the timepiece component.

[0008] For this purpose, the invention relates to a method for printing a functional element on a surface of a receiving zone of a timepiece component of a timepiece comprising the following steps: - preparation of a solution comprising a material constituting said functional element, said preparation step comprising a sub-step of defining specific properties of the solution as a function of preparation criteria, said properties being related to a viscosity and to a surface tension of this solution and the preparation criteria comprising: • at least one characteristic of structural modification of the timepiece component; • at least one characteristic of the construction of the functional element on the said receiving zone, • at least one structural characteristic of the material, and • at least one characteristic of the said receiving zone of the component, – deposition of the said prepared solution on the surface of the receiving area.

[0009] In other embodiments: the preparation step comprises a sub-step of composing a mixture relating to said solution as a function of the defined specific properties of this solution, said sub-step comprising a phase of producing a base preparation comprising said material and a base liquid, in particular a solvent; the composition sub-step includes a phase of selecting at least one product to be added to said base preparation, said at least one product being chosen from surface tension correction additives such as wetting agents; the composition sub-step comprises a phase of selecting at least one product to be added to said base preparation, said at least one product being chosen from dispersing agents contributing to the stability of the dispersion of particles of solid material; the solution preparation step comprises a sub-step of mixing at least one selected product with the base preparation; the deposition step includes a sub-step of applying the prepared solution over the entire surface of the receiving zone; the application sub-step is carried out using a printing technology of the "aerosol jet" type, "high density ink jet", "pneumatic metering", "extrusion metering" or else "super ink jet"; the application sub-step comprises a phase of transforming the prepared solution into an aerosol when the printing technology is by aerosol jet; the deposition step includes a sub-step of solidifying the material of the solution applied to the surface of the receiving zone; the solidification sub-step begins at the same time or substantially at the same time as the application sub-step and ends after this application sub-step has been carried out; the definition sub-step comprises a phase for determining said at least one structural modification characteristic of the timepiece component; the definition sub-step comprises a phase of determining said at least one construction characteristic of the functional element on said receiving zone, said construction characteristics comprising geometric dimensions and/or mechanical, chemical and/or aesthetic properties of the functional element to be built; the definition sub-step comprises a phase for determining said at least one structural characteristic of the material to be applied to said receiving zone, the structural characteristics comprising aesthetic, physical and/or chemical properties such as the density of said material; the definition sub-step includes a phase for determining the characteristics of the receiving zone of the timepiece component comprising geometric dimensions of the surface of the receiving zone likely to be covered by said layer and/or mechanical and/or chemical properties the material constituting this zone such as properties of adhesion, surface roughness and/or surface tension of this surface of the receiving zone; the specific properties of the definition sub-step also relate to a density of said solution; the material comprises at least one molecular precursor or at least one particle such as a metallic or metallic oxide particle, a monocrystalline or polycrystalline particle, an amorphous material particle, a ceramic particle, a polymer particle, a pigmented/colored particle, a colorless particle, a translucent/transparent particle, a fluorescent particle or even a phosphorescent particle; the material comprises at least one particle of the nanoparticle or microparticle type; the functional element applied to the surface of the receiving zone of the timepiece component of the timepiece comprises a decorative/aesthetic element, an element for adjusting the operation of a timepiece component such as an inertial mass or an element of interfacing; the method comprises a step of iterating the deposition step; the process is a process for printing, in particular by aerosol jet, a functional element on the surface of a receiving zone of the component of the timepiece contributing to the adjustment of the rate of this timepiece in particular by modifying the inertia and/or the unbalance of this component.

[0010] The invention also relates to a timepiece component comprising at least one receiving zone provided with a surface on which a functional element can be applied using said method.

[0011] Advantageously, the component is a balance wheel of the timepiece comprising an adjustment face provided with said at least one receiving zone capable of comprising the functional element for carrying out adjustment of the rate of the balance wheel, in particular by the modification of the inertia and/or the unbalance of this pendulum.

[0012] In particular, the surface of each receiving zone is non-flat.

The invention also relates to a timepiece comprising such a component.

Brief description of the drawings

Other features and advantages will emerge clearly from the description given below, by way of indication and in no way limiting, with reference to the appended figures, in which: FIGS. 1 and 2 each represent a top view of two variants of a timepiece component, for example here a balance wheel comprising receiving zones each intended to receive a functional element, according to one embodiment of the invention; FIGS. 3 to 5 show sectional views of three variants of receiving zone, according to the embodiment of the invention; FIG. 6 represents a schematic view of a timepiece comprising such a timepiece component provided with a receiving zone comprising the functional element, according to the embodiment of the invention, and FIG. 7 represents a flowchart relating to a process for printing the functional element on a receiving surface of each receiving zone of the timepiece component, according to the embodiment of the invention.

Detailed Description of Preferred Embodiments

With reference to Figures 1 to 7, the invention relates to a method for printing a functional element 2 on a receiving surface 5 of a receiving zone 3 of a watch component 1 of a piece of watchmaking 100. It will be noted that such a process is preferably an aerosol jet printing process also known by the expression "aerosol jet". It is however understood that in other embodiments, this method can implement other printing technologies of the "high density inkjet" type, pneumatic metering, metering by extrusion using an endless screw or again „great inkjet“. The process can also implement a printing technology providing for the production of bead deposits by points using spitting devices such as “micro-drops”. With this latest printing technology, these dots can be arranged close enough to each other to form a functional element 2 in a continuous line.

[0016] Such a method aims in particular for this functional element 2 printed on this surface 5 of the receiving zone 3 to be a functional element 2 which therefore finds a functional application only in the field of watchmaking. This functional element 2 is for example a decorative/aesthetic element, an element for setting/adjusting the operation of a watch component (for example: an inertial mass), an interfacing element or even an element for certain identification of the component watchmaker.

This functional element 2 is formed of a solid material which may comprise, in a non-exhaustive and non-limiting manner, at least one molecular precursor or at least one particle such as a metal or metal oxide particle, a monocrystalline or polycrystalline particle. (such as alumina, silicon), an amorphous material particle (glass, metal, etc.), a ceramic particle, a polymer particle, a pigmented/colored particle, a colorless particle, a translucent particle / transparent, a fluorescent particle or a phosphorescent particle. In addition, it will be noted that the particle can be of the nanoparticle or microparticle type.

For a better understanding of the invention, an embodiment is described here in which the functional element 2 printed on the surface 5 of the receiving zone 3 forms an adjustment/adjustment element which is of the type inertial mass. This inertial mass 2 makes it possible to take part in adjusting the rate of the timepiece in particular by modifying the inertia and/or the unbalance of a timepiece component 1 of this part 100, here a balance wheel. In addition, the invention can also make it possible to correct in this context the inertia and/or the unbalance of a balance-spring alone or of a balance-spring mounted in a movement 110 of the timepiece 100, which movement 110 that can be mounted in a case of this timepiece during correction operations. It is well understood that all the operations implemented within the framework of the printing method described below remain the same whatever the type of functional element 2 to be printed on the receiving zone 3.

Thus in this context, Figure 1 shows the balance 1 of a resonator 120 of the balance-spring type of a watch movement 110 of a timepiece 100. Such a balance 1 is provided with said at least a receiving zone 3 provided to receive the functional element 2 for carrying out the adjustment of the rate of this timepiece 100 and therefore of its movement 110. Such a receiving zone 3 can comprise: a recess defined in an upper face 4a of the balance 1 as shown in Figures 1 to 4, or a recess which is not represented here in the figures and which is defined in a lower face 4d and/or in a first lateral face 4b and/or of a second lateral face 4c of this rocker arm 1, or even a surface portion of the upper face 4a and/or of the lower face 4d and/or of the first lateral face 4b and/or of the second lateral face 4c of this rocker arm 1 as illustrated in FIGS. 1, 2 and 5.

The first and second side faces 4b, 4c respectively correspond to the outer and inner peripheral walls of the rim 11. The receiving zone 3 comprises the receiving surface 5 of the functional element 2 which can be: planar as in the variant of the receiving zone 3 illustrated in figure 3, or non-planar by being curved as shown in Figure 4 or by comprising sub-surfaces connected to each other in a perpendicular or substantially perpendicular manner as shown in Figure 5.

[0021] In addition, it will be noted that the reception surface 5 is defined over all or part of the reception zone 3.

In Figures 1 and 2, the balance 1 comprises a rim 11, a hub 12 intended to be pivotally mounted on a balance shaft, and one or more arms 13, for example two, three or four arms 13, connecting the rim 11 to the hub 12. The balance 1 comprises an adjustment face comprising at least one receiving zone 3 intended to receive the functional element 2. This adjustment face comprises in particular the upper face 4a and/or the lower face 4d and/ or the first side face 4b and/or the second side face 4c. This adjustment face is preferably oriented towards the back of the case of the timepiece 100 when the balance wheel 1 is included in the watch movement 110 which is for example mounted in this case, so that each receiving zone 3 is accessible for an impression of the functional element 2 on their reception surface 5. It will be noted that the upper face 4a comprises a first part comprised/defined in the rim 11 of the balance 1 and a second part in the arms 13 of this balance 1 Such an upper face 4a is flat or substantially flat, and extends in a plane orthogonal to the balance shaft.

As we have already mentioned, with reference to Figures 3 and 4, the receiving zone 3 may be a recess such as a groove, a cavity or even a concave structure, being provided with an opening , a solid bottom which may have a substantially flat surface as well as an internal wall connecting said opening to said bottom. A solid bottom should be understood here as being a bottom without an opening/orifice. In this configuration, the receiving surface 5 is formed by the bottom of this recess as in FIG. 3, or even by the bottom and a part of the internal wall as in FIG. 4. In the examples illustrated in these FIGS. 4, the recesses are defined only in the upper face 4a of the balance 1, and in particular in the rim 11, this face 4a then comprises several openings giving access to an interior volume of the corresponding recesses. In this configuration, each recess and therefore each corresponding interior volume is intended to receive the functional element 2 acting as an inertial mass in order to modify the inertia and/or the unbalance of the balance 1.

[0024] In an alternative not shown, this recess may be through forming a through hole or even a bottomless hole then comprising an opening at its two ends. In this configuration, the receiving surface is formed by the inner wall of this recess.

In another alternative illustrated in Figure 5, the receiving area 3 is not a recess and can then be defined both on a surface portion of the upper face 4a (or the lower face 4d) and a surface portion of one of the two side faces 4b, 4c. Alternatively, the receiving zone 3 can be located only on a surface portion of the upper face 4a or the lower face 4d or even a surface portion of the lateral face 4b, 4c.

[0026] In another alternative, the receiving zone 3 can be located both: on a surface portion of the upper face 4a and surface portions of the two side faces 4b, 4c, or on a surface portion of the lower face 4d and surface portions of the two side faces 4b, 4c.

[0027] The receiving zone 3 can be defined in/on the rim 11 or one of the arms 13 of the balance 1. When the balance 1 comprises several receiving zones 3, these can be distributed only in/on the arms 13 of this balance 1 or only in/on the rim 11 or then in/on the arms 13 and the rim 11 of this balance 1. Alternatively, when the balance 1 comprises a single receiving zone 3, this can be defined in the adjustment face on the entire contour of the serge 11.

In Figure 1, the serge 11 comprises several receiving zones 3, for example three zones 3, distributed around the periphery of the serge 11. Each receiving zone 3 extends along an arc of a circle at an angle comprised by example between 5° and 120° and preferably between 20° and 60°. In FIG. 2, the serge 11 comprises a multitude of receiving zones 3, for example four or more zones 3, which are distributed around the periphery of this serge 11. These receiving zones 3 extend according to an arc of a circle of angle less than 90° and preferably less than 45°. It is well understood that the invention can also be implemented for a serge comprising a single receiving zone 3 or two receiving zones 3 or even more than three receiving zones 3.

In these two embodiments, the receiving zones 3 can for example be distributed on this periphery of the serge 11 of the balance 1 in a regular manner so as to obtain a symmetrical distribution of the functional element 2 printed in all the receiving zones 3 or some of them in order to modify the inertia and/or the unbalance of the balance wheel 1 and thus precisely adjust the rate of the movement 110. The receiving zones 3 according to the two aforementioned embodiments can, depending on another example, be distributed around the periphery of the rim 11 asymmetrically in order to modify the inertia and/or the unbalance of the balance 1 and its center of mass by printing the functional element 2 in all the receiving zones 3 asymmetrical or some of them. In another example, the receiving zones 3 of the balance 1 are distributed symmetrically on the rim 11 of the balance 1 and the functional element 2 is printed only in some of these receiving zones 3 which have an asymmetrical configuration with respect to each other. others.

As we mentioned above, each receiving zone 3 leads to the adjustment face of the balance 1, this face when it consists solely of the upper face 4a and / or the two side faces 4b, 4c, is intended to be arranged substantially opposite the back of the case of the timepiece 100 when the timepiece movement 110 is mounted in this case. In such a configuration, it is therefore possible to make a final adjustment to the rate of the watch movement 110 when it is mounted in the middle part of the timepiece 100, before assembling the case back with the middle part, by adjusting a device for applying the functional element 2 above the balance wheel 1 while ensuring that the oscillating mass of this timepiece 100 is disengaged from the resonator 120 of the movement 110 for a movement of the automatic type. In this embodiment, the projection device is able to implement a printing technology of the aerosol jet type which allows very precise nebulization with a very small volume of material.

[0031] FIG. 7 represents the method of printing the functional element 2 on the surface 5 of the receiving zone 3 of the timepiece component 1 of the timepiece 100. More precisely, in the embodiment of the invention described here, the printing of such a functional element 2 on the watch component 1, the balance wheel 1 or even a balance-spring, participates in carrying out the adjustment of the rate of the timepiece 100. Under these conditions, such a process is also a process for printing, in particular by aerosol jet, the functional element 2 on the surface 5 of the receiving zone 3 of this component 1 of the timepiece 100 contributing to the adjustment of the rate of the timepiece 100 in particular by modifying the inertia and/or the unbalance of this component 1.

Such a method comprises a step 20 of preparing a solution comprising said material constituting the functional element 2 to be printed on the watch component 1. Such a solution can be in the more or less viscous or pasty liquid state. In this embodiment, this solution comprising this material can then be an ink, that is to say a liquid solution which can be dried by evaporation or cured by polymerization after its deposit on the receiving zone 3 so as to ensure the application of the solid material on this said zone 3.

This preparation step 20 comprises a sub-step 21 for defining specific properties of the solution according to preparation criteria. In this sub-step 21, the specific properties of the solution relate to the viscosity and the surface tension of this solution. In this embodiment, these properties are also related to the density of said solution. With regard to the preparation criteria, these include: • at least one characteristic of structural modification of the watch component 1; • at least one construction feature of the functional element 2 on said receiving zone 3; • at least one structural characteristic of the solid material constituting the functional element 2 to be applied to said receiving zone 3 • at least one characteristic of said receiving zone 3 of component 1, and • at least one characteristic of the printing technology implemented work by this method.

[0034] The definition sub-step 21 comprises a phase 22 for determining said at least one structural modification characteristic of the timepiece component 1. In the context of this embodiment of the invention in which the application of the functional element 2 on this component 1 aims to adjust the rate of the timepiece 100, this said at least one structural modification characteristic comprises a rate correction value resulting from inertia and/or unbalance correction values of the balance wheel 1 in order to obtain an adjusted/corrected rate of the watch movement 110 and therefore of the timepiece 100.

[0035] Still in the context of this embodiment of the invention in which the application of the functional element 2 on this component 1 aims to adjust the rate of the timepiece 100, this determination phase 22 comprises a measurement sub-phase 23 of the rate of the watch movement 110. This measurement can preferably be carried out without contact since access to the resonator is particularly narrow. In a known manner, the measurement of the rate of the movement 110 can thus be carried out, for example, according to optical and/or acoustic technologies. This measurement sub-phase 23 makes it possible to compare the measured rate with a desired rate. On the other hand, it also makes it possible to know the beat of the balance 1 in order to be able to synchronize it with the impression of the functional element 2 on the receiving surface 5 of each receiving zone 3 of the balance 1.

Still in the context of this embodiment aimed at adjusting the rate of the timepiece 100, the determination phase 22 then includes a sub-phase 24a for estimating the correction value of the inertia of the pendulum 1 to obtain a corrected rate. This correction value is determined by the following known formulas:

[0037] For a resonator of the balance-spring type, the moment of inertia l of the balance corresponds to the formula: in which m represents the mass of the balance 1 and r its radius of gyration which also depends on the temperature via the coefficient of expansion of the pendulum 1.

In addition, the elastic torque C of the constant-section hairspring corresponds to the formula: in which E is the Young's modulus of the material used, h its height, e its thickness and L its developed length. Finally, the frequency f of the resonator 120 comprising the balance-spring corresponds to the formula:

The determination phase 22 also includes a sub-phase 24b for estimating the correction value of the unbalance of the balance 1 to obtain a corrected rate. The estimation of such a correction value is well known in the state of the art and is described in particular in the documents WO2012007460 and EP2864844A1. Subsequently, the definition sub-step 21 comprises a phase 25 for determining said at least one construction characteristic of the functional element 2 on said receiving zone 3. During this phase 25, the construction characteristics such as geometric dimensions and/or mechanical, chemical and/or aesthetic properties of the functional element 2 are determined. It will be noted that the geometric dimensions of the functional element 2 which are determined here relate in particular to the thickness, the length, the width and/or the radius of this functional element 2, making it possible to define the value of the rate correction. The functional element 2 which is built on the receiving zone can have a rectangular section or even a section representing a portion of a disc. This section here depends on the surface tensions of the solution and the receiving surface of the receiving zone 3.

This definition sub-step 21 also includes a phase 26 for determining said at least one structural characteristic of the material to be applied to said receiving zone 3. During this phase 26, the structural characteristics such as aesthetic properties, physical and/or chemicals such as the density and surface tension of this material, are determined. It will be noted that this density of the material is that of this same material which will constitute the functional element 2 printed on the receiving zone 3 and therefore after the solidification of this element 2 on this zone 3 in particular following the evaporation of a solvent of the solution.

The definition sub-step 21 also includes a phase 27 for determining said at least one characteristic of said receiving zone 3 of component 1. During this phase 27, the characteristics of the receiving zone 3 such as geometric dimensions of the surface of the receiving zone 3 likely to be covered by the functional element 2 and/or of the mechanical and/or chemical properties of the material constituting this zone 3 such as properties 5 of adhesion and/or of roughness of the surface and/or surface energy and/or surface tension of the surface of this receiving zone 3 are determined.

[0042] In addition, as we mentioned above, several printing technologies can be implemented by the printing process. Under these conditions, such a method provides, during the definition sub-step 21, for a determination phase 28 of at least one characteristic of the printing technology implemented in this method. Thus this phase 28 makes it possible to identify the printing technology used.

Such determination phases referenced 25, 26 and 27 are preferably carried out by experimentation on substrates equivalent to the receiving surface 5 of the receiving zone 3 of the timepiece component 1 which it is desired to modify. Such phases may include, in a non-limiting and non-exhaustive manner, observation operations under an optical microscope, performance of adhesion tests, optical or mechanical profilometry, scanning electron microscopy (in English, SEM), dispersive X-ray spectroscopy (EDX), substrate surface energy measurements based on reference liquids (e.g. water, ethylene glycol), solution surface tension measurements and/or wettability tests such as the contact angle measurement between the solution and the substrate constituting the receiving zone 3.

Next, the definition sub-step 21 comprises a generation phase 29 of the specific properties of the solution from said preparation criteria estimated during the determination phases 25, 26, 27, 28 above. It should be recalled that these preparation criteria make it possible in particular to determine the quantity and nature of the solid material to be applied to the surface of the receiving zone of the watch component with regard to which, quantity and nature of the material, the properties of viscosity, surface tension and density are estimated. It will be noted in particular that the quantity and the nature of the material are determining in particular for the properties of density, viscosity and also for the choice of the additives which contribute to defining the surface tension of the solution.

During this generation phase 29, the viscosity property of the solution which is determined on the basis of these preparation criteria, must be large enough to avoid the spreading, or even the bursting of drops resulting from the projection of the solution beyond the target receiving zone 3 of the printing of this solution. This viscosity property is therefore established in consideration of the size of the receiving zone 3 and in some variant also in consideration of aesthetic criteria relating to the final appearance of the functional element 2. By way of example, for a receiving zone 3 limited to a width of the order of 100 μm, the viscosity property of the determined solution defines a viscosity which must be greater than 1 cP, preferably greater than 50 cP. It will also be noted that depending on the type of printing technology implemented by the printing process, a very high viscosity would be likely to hinder the smooth running of this process, in particular by altering the printing speed implemented. in this last. For example, in aerosol jet printing, a viscosity above 1000 cP could prevent the aerosol jet from being produced.

Regarding the surface tension property of this solution, during this generation phase 29, such a property is adjusted in correspondence with the surface energy of the substrate in the receiving zone 3. This surface tension of the solution is preferably lower than the surface energy of this substrate. This condition can be analyzed by measurements of either quantity. The surface energy of the substrate can be measured, for example, as a function of the contact angle with reference solvents like water, ethylene glycol or diiodomethane. The surface tension of the solution can be determined, for example, by the hanging drop method. Alternatively, the contact angle can be measured directly between the solution and the substrate. In general, it will be sought to have good wettability, that is, a contact angle comprised approximately between 0° and 90°. To obtain this condition, it is possible to act on the surface tension of the solution, by adding wetting agents (surface tension correcting additives), or by modifying the substrate of the receiving zone to change its surface energy. When this modification of the substrate is spatially controlled, it brings an additional advantage of definition of the receiving zone 3.

As regards the property relating to the density of the solution, it is above all determined by the proportion by mass of the solid material which makes up this solution as well as by the intrinsic density of this material. It is understood that a high density of the solution makes it possible to add mass more quickly to the watch component to be treated, which represents an advantage in terms of industrial production. On the other hand, the amount of solid material also determines the viscosity and in very large amounts can limit the accuracy or even the ability to achieve the print.

Subsequently, the preparation step 20 comprises a sub-step 30 of composition of a mixture relating to said solution according to the specific properties defined above relating to this solution. Such a sub-step 30 comprises a phase 31 of producing a base preparation comprising said solid material according to the nature and the quantity determined previously, and a base liquid, for example a solvent or a mixture of different solvents. Thereafter, this sub-step 30 includes a selection phase 32 of at least one product to be added to said basic preparation, said at least one product being chosen from the following products: surface tension correcting additives such as wetting agents, and/or dispersing agents contributing to the stability of the dispersion of particles of the solid material.

Then, the step 20 of preparing the solution may optionally comprise a sub-step 33 of mixing at least one selected product with the base preparation. During this sub-step 33, the correction additive(s) and/or dispersant(s) is (are) added to the base preparation according to the specific properties defined previously for the solution. More specifically, during this mixing sub-step 33, the solution should be obtained by adjusting: the viscosity of this solution according to the determined viscosity and this, by varying the proportion of the selected product(s) of the mixture, mainly the solvent depending on the quantity and nature of the material and; the surface tension of this solution according to the surface tension determined and this, by varying according to the quantity and the nature of the material, the proportion of the product or products selected from the mixture, mainly the additives; the density of this solution according to the determined density and this, by varying according to the quantity and the nature of the material, the proportion of the product or products selected from the mixture, mainly the quantity of particles.

Subsequently, the method comprises a step 34 of depositing the prepared solution over the entire surface 5 of the receiving zone 3. In this embodiment, such a step 34 contributes to participating in the construction of the element function 2 on one or more receiving zones 3 of the balance 1 in order to modify the inertia and/or the unbalance of this balance 1 according to the rate correction value. This deposition step 34 includes a sub-step 35 of applying the prepared solution over the entire surface 5 of the receiving zone 3 of the component 1. Such a sub-step 35 contributes to the application of the solution comprising the material on the component 1 with a view to constructing the functional element 2. Such an application sub-step 35 comprises a phase of transformation 36 of the prepared solution into an aerosol when the printing technology is by aerosol jet. This phase 36 includes a nebulization sub-phase 37 of the prepared solution which contributes to transforming this solution into an aerosol.

The deposition step 34 then comprises a sub-step 38 of solidification of the material of the solution applied to the surface of the receiving zone 3. This sub-step 38 aims to finalize the construction of this functional element 2 applied to the receiving zone 3 of component 1. This sub-step 38 may consist in continuing the evaporation of the solvent of the solution having started as soon as the application sub-step 35 is implemented, in thermosetting the material constituting the element functional 2 or even to crosslink this material on the surface 5 of the receiving zone 3. As we have just mentioned, this sub-step of solidification 38 preferably begins at the same time or substantially at the same time as the sub-step application 35 and ends after this application sub-step 35 has been carried out, in order to improve the positioning precision of the functional element 2 in the receiving zone 3.

The method may provide for a reiteration step 39 of the deposition step 34 which is implemented as many times as necessary in order to build the functional element 2 on the receiving zone 3 of the watch component 1. This functional element 2 can be in one piece or be formed from several separate parts such as for example a succession of points separated from each other.

Thus, thanks in particular to the preparation and the particular composition of the solution comprising the material to be applied to the watch component 1, the method advantageously allows the production of an impression of the functional element 2 on this component 1 which is targeted and very precise. In terms of positioning, it is possible to achieve a centering of the deposits of the order of 5 μm of precision. This is more limited by the system of micro-positioning motors than by the ejection targeting of the final mixture. As for the quantity of material added, it can be controlled in the order of nano-grams, well below the sensitivity threshold of watchmaking applications.

[0054] In addition, this printing of the functional element 2 of the inertial mass type is carried out without the production of splashes/projections subsequent to the deposition as is expected for the production of a watch component 1 and this, with a high degree of control over the inertial mass deposited. It will be noted that the production of such splashes/satellites during deposition is often the cause of the contamination of the watch movement 110 and of potential malfunctions of the latter. Moreover, this process allows a homogeneous application, and therefore with a homogeneous mass distribution, of the material on the timepiece component 1 and this, whether the surface 5 of the receiving zone 3 is flat or non-flat. In other words, the functional element 2 can be printed homogeneously and with the same resolution over an entire three-dimensional receiving surface 5 of a timepiece component 1 that is stationary or in motion. It should be noted in addition that such a solution thus developed also contributes to: geometrically define the position of the functional element 2 on the surface 5 of the receiving zone 3; improve the aesthetics of the functional element 2 on the receiving surface 5; facilitate the adhesion of the functional element 2 to this surface 5, independently of any preparation of this surface 5; provide a printing process that is repeatable, and to propose a printing process which can be industrialized.

In one example, such an invention can be implemented in the context of an adjustment of a moment of inertia of a horological resonator of the balance-spring type, such an adjustment aiming to correct the rate of the oscillator of an order of magnitude of -5 seconds/day. It is understood first that the negative sign indicates here that the rate can be corrected only by reducing the frequency of oscillation, because the addition of material of the invention can only increase the inertial moment of the balance. In this context, if we consider the mass and the radius of the rim of a standard watch balance wheel, it can be estimated that an impression of the functional element on the rim of the balance wheel comprising the solid material having a mass of the order of about ten micrograms makes it possible to carry out such a correction of the gait according to the order of magnitude stated above. To do this, the solution comprising said functional element comprises: – 95% by weight of the base preparation, i.e.: • 20% by weight of a solvent such as water, and • 75% by weight of the solid material such at least one tungsten carbide nanoparticle produced by the company US Research Nanomaterials, Inc and which has a size between 150 nm and 200 nm, and – 5% by weight of a wetting agent such as a polyurethane additive produced by the Lubrizol company under the Solsperse Solsperse®J948 brand. Such a solution is configured for the "aerosol jet" type printing technology, thus allowing a flow of solid material of the order of 2 µg of tungsten carbide per second . The viscosity and the surface tension of this solution make it possible to target the deposit on an arc section of the balance rim with a thickness of 300 µm. Thus, the correction of the rate of the watch resonator can be accomplished within a few seconds. In addition, it should be noted that with 75% by weight of Tungsten carbide (density 15.6 g/ml) and 25% by weight of water and 5% by weight of Polyurethane additive (density -1 g/ml), the density of the solution is here of the order of 3.4 g/ml.

Claims (23)

1. Method for printing a functional element (2) on a surface (5) of a receiving zone (3) of a timepiece component (1) of a timepiece (100) comprising the following steps : – preparation (20) of a solution comprising a material constituting said functional element (2), said preparation step (20) comprising a sub-step of defining (21) specific properties of the solution according to preparation criteria, said properties being related to a viscosity and a surface tension of this solution and the preparation criteria comprising: • at least one feature of structural modification of the watch component (1); • at least one construction feature of the functional element (2) on said receiving zone (3), • at least one structural characteristic of the material, and • at least one characteristic of said receiving zone (3) of the component (1), – deposit (34) of said prepared solution on the surface (5) of the receiving zone. 2. Method according to the preceding claim, characterized in that the preparation step (20) comprises a sub-step of composition (30) of a mixture relating to said solution according to the defined specific properties of this solution, said sub-step -step (30) comprising a phase of production (31) of a base preparation comprising said material and a base liquid, in particular a solvent. 3. Method according to the preceding claim, characterized in that said composition sub-step (30) comprises a selection phase (32) of at least one product to be added to said basic preparation, said at least products being chosen from : – surface tension correction additives such as wetting agents, and/or – dispersing agents contributing to the stability of the dispersion of particles of the solid material. 4. Method according to any one of the preceding claims, characterized in that the step of preparing (20) the solution comprises a sub-step of mixing (33) at least one selected product with the base preparation. 5. Method according to any one of the preceding claims, characterized in that the step of depositing (34) comprises a sub-step of applying (35) the solution prepared over the entire surface (5) of the receiving zone. (3). 6. Method according to the preceding claim, characterized in that the application sub-step (35) is carried out using a printing technology of the "aerosol jet" type, "high density ink jet", "pneumatic metering". , „extrusion dosing“ or even „super ink jet“. 7. Method according to any one of claims 5 and 6, characterized in that the application sub-step (35) comprises a phase of transformation (36) of the solution prepared into an aerosol when the printing technology is by aerosol jet. 8. Method according to any one of the preceding claims, characterized in that the step of depositing (34) comprises a sub-step of solidifying (38) the material of the solution applied to the surface of the receiving zone (3) . 9. Method according to the preceding claim, characterized in that the solidification sub-step (38) begins at the same time or substantially at the same time as the application sub-step (35) and ends after the completion of this applying sub-step (35). 10. Method according to any one of the preceding claims, characterized in that the definition sub-step (21) comprises a phase of determining (22) said at least one structural modification characteristic of the timepiece component (1). 11. Method according to any one of the preceding claims, characterized in that the definition sub-step (21) comprises a phase of determining (25) said at least one construction characteristic of the functional element (1) on said receiving zone (3), said construction characteristics comprising geometric dimensions and/or mechanical, chemical and/or aesthetic properties of the functional element (2) to be constructed. 12. Method according to any one of the preceding claims, characterized in that the definition sub-step (21) comprises a phase of determining (26) said at least one structural characteristic of the material to be applied to said receiving zone (3 ), the structural characteristics including aesthetic, physical and/or chemical properties such as the density of said material. 13. Method according to any one of the preceding claims, characterized in that the definition sub-step (21) comprises a phase of determining (27) the characteristics of the receiving zone (3) of the timepiece component (1) comprising geometric dimensions of the surface (5) of the receiving zone (3) likely to be covered by said layer and/or of the mechanical and/or chemical properties of the material constituting this zone such as properties of adhesion, roughness of the surface and/or surface tension of this surface of the receiving zone (3). 14. Method according to any one of the preceding claims, characterized in that the specific properties of the definition sub-step (21) also relate to a density of said solution. 15. Method according to any one of the preceding claims, characterized in that the material comprises at least one molecular precursor or at least one particle such as a metal or metal oxide particle, a monocrystalline or polycrystalline particle, a particle of amorphous material, a ceramic particle, a polymer particle, a pigmented/colored particle, a colorless particle, a translucent/transparent particle, a fluorescent particle or even a phosphorescent particle. 16. Method according to any one of the preceding claims, characterized in that the material comprises at least one particle of the nanoparticle or microparticle type. 17. Method according to any one of the preceding claims, characterized in that the functional element (2) applied to the surface (5) of the receiving zone (3) of the timepiece component (1) of the timepiece ( 100) comprises a decorative/aesthetic element, an element for adjusting the operation of a timepiece component such as an inertial mass or an interface element. 18. Method according to any one of the preceding claims, characterized in that it comprises a step of reiteration (39) of the step of depositing (34) 19. Method according to any one of the preceding claims, characterized in that it is a method of printing, in particular by aerosol jet, of a functional element (2) on the surface (5) of an area receiver (3) of the component (1) of the timepiece (100) contributing to the adjustment of the rate of this timepiece (100) in particular by modifying the inertia and/or the unbalance of this component ( 1). 20. Timepiece component (1) comprising at least one receiving zone (3) provided with a surface (5) on which a functional element (2) can be applied using the method according to any one of the preceding claims. . 21. Timepiece component (1) according to the preceding claim, characterized in that it is a balance of the timepiece (100) comprising an adjustment face provided with said at least one receiving zone (3) capable of comprising the 'functional element (2) for a realization of an adjustment of the march of the pendulum in particular by modifying the inertia and/or the unbalance of this pendulum. 22. Component (1) according to any one of claims 20 and 21, characterized in that the surface (5) of each receiving zone (3) is non-planar. 23. Timepiece (100) comprising a component (1) according to any one of claims 20 to 22.