CH712264A2 - Method of decorating a watch component - Google Patents

Abstract

The invention relates to a method for decorating a watch component (1) comprising: a) a step of preparing the watch component (1) optionally comprising a first step of depositing a first material on the watch component (1); ) to form a first sub-layer (2), b) a second step of depositing a second material on the watch component (1) obtained in step a) to form a second sub-layer (4), c ) a coloring step comprising depositing a third color material on the watch component (1) obtained in step b) to form a color outer decorative layer (5). According to the invention, at least step b) and step c) are carried out by a physical vapor deposition process (PVD).

Description

Description

Field of the Invention [0001] The invention relates to a method of decorating a component.

Watchmaker comprising a step of preparing the watch component, a corrosion protection step, and a coloring step to form an outer color decoration layer.

BACKGROUND OF THE INVENTION [0003] Such a method is conventionally used to produce watch components, more particularly needles and sconces, and in particular brass needles and sconces.

According to this method, the watch component is prepared by depositing on all sides of the watch component a first protective layer by galvanic means. This technique has the advantage of being able to pretreat large quantities of components at a relatively high rate. The component then undergoes a mechanical diamonding operation which makes it possible, by producing facets, to give the component a shiny and glittering appearance. The component is then again galvanically treated to deposit on all the faces of the component a corrosion protection layer, as well as an external color decorative layer. These galvanic operations are this time complex because of the delicate surfaces obtained after diamonding. As a result, the color of the outer decorative layer can sometimes have heterogeneities, which results in the scrapping of the component. In addition, with this galvanic technique, the production costs are high and it is not possible to deposit all the alloys to obtain all the colors possible. SUMMARY OF THE INVENTION [0005] One of the objectives of the invention is to overcome these various disadvantages.

More specifically, an object of the invention is to provide an industrial method of decorating watch components, simple to implement and streamlined, to reduce production costs.

Another object of the invention is to provide an industrial method of decorating watch components to reduce the rate of disposal or waste.

For this purpose, the present invention relates to a method of decorating a watch component comprising: a) a step of preparing the watch component optionally comprising a first step of depositing a first material on the watch component to form a first sub-layer, b) a second step of depositing a second material on the watch component obtained in the preparation step a) to form a second sub-layer, c) a coloring step comprising depositing a second sub-layer; a third color material on the watch component obtained in the second deposition step b) to form a color external decoration layer.

According to the invention, at least the second deposition step b) and the coloring step c) are performed by a physical vapor deposition process (Physical Vapor Deposition, PVD).

Advantageously, the first deposition step during the preparation step a) can also be carried out by a physical vapor deposition process.

According to a preferred embodiment of the invention, at least the second deposition step b) and the coloring step c), and optionally the first deposition step during the preparation step a) , are performed without breaking vacuum conditions.

The method according to the invention thus allows a rationalization of the implementation of its different steps. In addition, it makes it possible to obtain a color external decoration layer having a great homogeneity, and thus to reduce the scrapping rate of the watch components.

BRIEF DESCRIPTION OF THE DRAWINGS [0013] Other characteristics and advantages of the invention will appear more clearly on reading the following description of an embodiment of the invention, given as a simple illustrative and nonlimiting example, and annexed figures, among which: FIGS. 1 to 5 show a sectional view of a watch component processed according to the different steps of the method according to the invention.

Detailed Description of a Preferred Embodiment [0014] Referring to FIG. 1, there is shown a sectional view of a raw watch component 1, for example a needle, in particular a brass or bronze needle.

The watch component may for example be chosen from the group comprising hands, appliques, dials, highlights, glasses, crowns, pushers, oscillating masses, wheels, bridges, plates, or any other element or member used in a timepiece to which it is desired to give a color.

The watch component 1 is first prepared according to the preparation step a) of the method of the invention. This preparation step may comprise, for example, optionally, a first step of depositing a first material on the watch component 1 to form a first underlayer 2 as shown in FIG. 2. Preferably, the first sub-layer 2 covers all the faces of the watch component 1. The deposition of this first sub-layer 2 can be carried out by galvanic means in a manner known to those skilled in the art. A PVD deposit can also be advantageously used, as will be seen below.

The first sub-layer 2 is in particular a protective underlayer which is necessary when the preparation step a) comprises a diamond step. This step consists in forming on the surface of the watch component 1 which will be visible from outside the timepiece, beveled surfaces or facets 3 with the aid of a tool set with diamonds, as shown in FIG. 3. This mechanical treatment makes it possible to give a shiny and glittering appearance to the watch component 1. After the diamonding, the first underlayer 2 has been removed on the top of the watch component 1, as shown in FIG. 4. Other operations similar to diamation may also be possible (satin, sunburst, brushing or brightening).

The first sub-layer 2 also promotes the adhesion of other layers to come on the watch component 1.

The preparation step a) may further comprise a cleaning step of the watch component 1 obtained after diamonding. In a manner known to those skilled in the art, the cleaning step can be carried out for example by chemical degreasing, followed by rinsing with city water and demineralised water. The watch component 1 is then dried and is ready for the implementation of the second deposition step b).

Said second deposition step b) comprises the deposition of a second material on the watch component 1 obtained in the preparation step a) to form a second sub-layer 4. This second sub-layer 4 constitutes in particular a second sub-layer of corrosion protection. It also makes it possible to promote the adhesion of the decorative layer 5 to the watch component 1. The color of this second underlayer 4 may advantageously be chosen close to the color of the decorative layer 5 in order to avoid a visible contrast in wear case of said decorative layer 5.

Then according to the coloring step c), a third color material is deposited on the watch component 1 obtained at the second deposition step b) to form a color external decoration layer 5.

According to the invention, at least the second deposition step b) and the coloring step c) are performed by a physical vapor deposition process (Physical Vapor Deposition, PVD).

The watch components decorated according to the method of the invention comprise an outer decorative layer 5 having a particularly homogeneous color, so that the waste rate is very low.

In a particularly advantageous manner, the second sub-layer 4 and the decorative layer 5 are deposited only on the diamond surfaces 3 and on the sides of the watch component. It is however possible to provide during the coloring step c) a reversal step or the use of an installation for PVD deposition on both sides of the watch component, if it is desired that the second under layer 4 and the decorative layer 5 are also present on the back of the component.

Preferably, the first deposition step during step a) is also performed by a physical vapor deposition method instead of a galvanic deposition.

According to a particularly preferred embodiment, the physical vapor deposition process may be a sputtering method. The sputtering gas is inert, typically argon. The PVD deposition parameters are determined by those skilled in the art in order to meet the color and quality criteria specific to the function and / or model selected.

The method according to the invention may also comprise, before the implementation of the second deposition step b) an ionic activation step. The parameters of the ionic activation are determined by those skilled in the art. The ionic activation ensures the perfect adhesion of the second sub-layer 4 deposited directly on the diamond surfaces 3 of the watch component 1 exposed during the diamondizing operation.

In a particularly preferred manner, at least the second deposition step b) and the coloring step c), and optionally the first deposition step during the preparation step a), are carried out without rupture of vacuum conditions in the same installation, which allows a simple and economical industrial implementation of the method of the invention.

Advantageously, the first material is chosen so that the first sub-layer 2 protects the watch component 1 and / or promotes the adhesion of the second sub-layer 4 and the external decoration layer of color 5. Similarly, the second material is chosen so that the second underlayer 4 protects the watch component 1 from corrosion and / or promotes the adhesion of the external decorative layer of color 5. Preferably, at least the second material is an anticorrosive material.

Preferably, the first material and / or the second material may be chosen from the group comprising nickel, chromium, a stainless steel, tin, precious metals, and their alloys (for example an alloy Cr / Ni (eg inconel), Sn / Ni or Pd / Ni).

The first material and / or the second material may comprise nickel in an amount of between 0% and 100% by weight.

In particular, the first material may be nickel.

According to another embodiment, the first and / or second material may be an alloy of chromium and nickel, comprising chromium in an amount of between 20% and 80% by weight, and preferably between 30%. and 70% by weight.

In the case of a process performed without breaking vacuum conditions, the first material is preferably identical to the second material, which further streamlines the process.

Preferably, the second sub-layer 4 may have a thickness of between 200 nm and 1500 nm.

More generally, the composition and the thickness of the second sub-layer 4 are adapted to the nature of the material of the watch component 1 and the third material.

Advantageously, the third color material may be chosen from the group comprising precious metals and their alloys, or materials intrinsically stable over time, such as aluminum, and their alloys, and ceramics. The ceramic may be colored, such as titanium nitride, or transparent to reveal the color of the second underlayer.

In particular, the third color material may be chosen from the group comprising gold, silver, palladium, platinum, rhodium and their alloys.

In a particularly advantageous manner, the third color material is an 18K 5N gold alloy, or a nickel-free and cobalt-free 18.5K gold alloy comprising by weight between 75% and 77.5% by weight. gold, between 1.2% and 1.6% of palladium and between 20.1% and 23.8% of copper. The patent CH 705 653, the content of which is incorporated herein by reference, describes such a massive alloy as having improved discoloration characteristics.

This alloy is particularly preferred for the application of the external color decoration layer by the PVD route because it provides a decorative layer, which in addition to having a homogeneous color and a constant title with respect to As the third material, has fade resistance and fading better than that of a layer obtained from the same alloy but deposited by the galvanic route. In addition, the corrosion resistance of the decorative layer obtained according to the method of the invention is greater than that of the solid alloy.

Preferably, the outer color-coating layer 5 has a thickness of between 100 nm and 1500 nm.

The method of the invention provides an industrial production of watch components having a color decoration layer of high quality, filed with reliability and repeatability. In addition, it allows the use of many alloys with many colors to make layers of decoration of very different colors.

The following example illustrates the present invention without however limiting the scope.

Example: Cut needles in brass are coated with a first sublayer of nickel galvanically and are diamond. Then a washing of the needles is carried out.

The needles thus prepared are then aligned on the substrate holder of a PVD / sputtering machine on the market. They are spaced so as to allow the passage of the plasma.

The PVD treatment is then carried out. There is no heating phase so as not to deform the needles.

After ionic activation of the needles, is deposited under argon the second sub-layer 4 based on nickel and chromium and the decoration layer 5 of gold alloy. The gold alloy is the nickel-free and cobalt-free 18.5K alloy comprising by weight between 75% and 77.5% gold, between 1.2% and 1.6% palladium and between 20.1% and 23.8% of copper described in patent CH 705 653. The PVD deposition parameters are chosen so as to deposit a second sublayer 4 based on nickel and chromium of 1 μm and an alloy decorative layer 5 of 0.5 pm.

Needles treated according to the method of the invention have a very homogeneous color so that the rate of waste is regularly less than 1%.

Claims (16)

By way of comparison, needles for which the external color decorative layer is based on the same 18.5K gold alloy as described in patent CH 705 653, are treated in a manner similar to the invention but according to a method in which the second deposition step b) is carried out electroplically and the coloring step c) is carried out by PVD. These needles typically have a waste rate greater than 5%. For comparison also, needles for which the external color decoration layer is based on gold 18 K 5N, and treated similarly to the invention but with a fully galvanic process (including for the steps b) and c)), have a waste rate greater than 5%. claims 1. A method of decorating a watch component (1) comprising: a) a step of preparing the watch component (1) optionally comprising a first step of depositing a first material on the watch component (1) to form a first sub-layer (2), b) a second step of depositing a second material on the watch component (1) obtained in the preparation step a) to form a second sub-layer (4), c) a step coloring process comprising depositing a third color material on the watch component (1) obtained in the second deposition step b) to form an outer color-coating layer (5), characterized in that at least the second deposition step b) and the coloring step c) are performed by a physical vapor deposition process (PVD). 2. Method according to claim 1, characterized in that the first deposition step in the preparation step a) is performed by a physical vapor deposition process. 3. Method according to claim 1 or 2, characterized in that the first material is chosen so that the first sub-layer (2) protects the watch component (1) and / or promotes the adhesion of the second underlayer (4) and the external color decorative layer (5). 4. Method according to one of the preceding claims, characterized in that the second material is chosen so that the second sub-layer (4) protects the watch component (1) from corrosion and / or promotes the adhesion of the external color decoration layer (5). 5. Method according to one of the preceding claims, characterized in that the second material is chosen so that the color of the second sub-layer (4) is close to the color of the external decorative layer of color (5) . 6. Method according to one of the preceding claims, characterized in that the first material and / or the second material is selected from the group comprising nickel, chromium, stainless steel, tin, precious metals, and their alloys. 7. Process according to claim 6, characterized in that the first material and / or the second material is an alloy of nickel and chromium, the amount of chromium being between 20% and 80% by weight, and preferably between 30% and 80% by weight. % and 70% by weight. 8. Method according to one of the preceding claims, characterized in that the second sub-layer (4) has a thickness between 200 nm and 1500 nm. 9. Method according to one of the preceding claims, characterized in that the third color material is selected from the group comprising precious metals and their alloys, aluminum and its alloys, and ceramics. 10. The method of claim 9, characterized in that the third color material is selected from the group consisting of gold, silver, palladium, platinum, rhodium and their alloys. 11. Process according to claim 10, characterized in that the third color material is a nickel-free and cobalt-free gold alloy comprising, by weight, between 75% and 77.5% of gold, between 1.2% and 1%. , 6% of palladium and between 20.1% and 23.8% of copper. 12. Method according to one of the preceding claims, characterized in that the external color decoration layer (5) has a thickness between 100 nm and 1500 nm. 13. Method according to one of the preceding claims, characterized in that the physical vapor deposition process is a sputtering method. 14. Method according to one of the preceding claims, characterized in that the preparation step a) comprises a diamond step. 15. Method according to one of the preceding claims, characterized in that at least the second deposition step b) and the coloring step c), and optionally the first deposition step during the preparation step has ), are performed without breaking vacuum conditions. 16. Method according to one of the preceding claims, characterized in that the watch component (1) is selected from the group comprising the needles, the appliques, the dials, the highlights, the glasses, the crowns, the pushers, the masses oscillating wheels, turntables and decks.