Method for manufacturing dial

Abstract

The invention relates to a method for manufacturing a dial comprising the following steps: - forming a first part of the dial in a first resin loaded with reflective particles, the first part forming a housing; - pouring at least a second resin into the housing to form the second part of the dial and obtain a dial; - polishing totally or selectively the dial to locally reveal the first resin comprising the reflective particles.

Description

Technical field of the invention

[0001] The invention relates to the field of watchmaking. More specifically, it concerns a method for manufacturing a dial that has the appearance of a precious stone.

[0002] In this text, the term "precious stone" refers without distinction to precious and semi-precious stones. Technological background

[0003] Gemstone-based composites are commonly used in fields such as watchmaking and jewelry. The desired properties can vary, but they are generally aesthetic and mechanical, though they are relatively expensive.

[0004] Thus, for economic reasons, watch components with an appearance that imitates that of precious stones have been developed in polymer material.

[0005] However, the manufacture of these decorative elements still requires the use of synthetically produced stones, and still involves a high manufacturing cost.

[0006] There is therefore a need for a decorative element whose manufacture has a reduced cost while retaining the appearance of precious stones, namely the brilliance or sparkle, thus giving the decorated object a luxurious appearance. Summary of the invention

[0007] To this end, the present invention relates to a method for manufacturing a dial comprising the following steps: form a first part of the dial in a first resin loaded with reflective particles, the first part forming a housing; pour at least a second resin into the housing to form the second part of the dial and obtain a dial; polish totally or selectively the dial to locally reveal the first resin containing the reflective particles.

[0008] In accordance with other advantageous variants of the invention: the first resin is a thermoplastic resin, an epoxy resin or a polyurethane resin and the second resin is an epoxy resin or a polyurethane resin; the reflective particles are chosen from phosphorescent, fluorescent, metallic, precious, semi-precious particles or a combination of these particles; the second resin includes at least one additive chosen from colorants, pigments, anti-UV agents or a combination of these additives; several resins are poured into the housing of the first dial part; the second resin is poured into the housing of the first dial part so as to partially fill the housing; the charge of reflective particles integrated into the first resin is between 0.001% and 5%; the charge of reflective particles integrated into the first resin is between 0.0.2% and 1%; the accommodation includes decorative elements in positive relief; the decorative elements are indices, appliques, logos or geometric shapes.

[0009] The present invention also relates to a dial made by a process as described above. Brief description of the figures

[0010] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings in which: there figure 1 represents a step in the realization of a dial of the process according to the present invention; the figure 2 represents the dial obtained following the implementation of the step of the figure 1 ; there figure 3 represents a dial according to a first embodiment of the process according to the present invention; the figure 4represents a dial according to a second embodiment of the process according to the present invention; the figure 5 represents a dial according to a third embodiment of the process according to the present invention. Detailed description of the invention

[0011] The invention relates to a method for manufacturing a dial 1 comprising the following steps: form a first part 10 of the dial in a first resin loaded with reflective particles, the first part forming a housing 11; pour at least a second resin into the housing 11 to form a second part 12 of the dial and obtain a dial 1; polish totally or selectively the dial 1 to locally reveal the first resin comprising the reflective particles.

[0012] The first resin is chosen from thermoplastic, epoxy, or polyurethane resins, and the second resin is chosen from epoxy or polyurethane resins. Generally, these resins harden through the polymerization of monomers and / or prepolymers and / or through crosslinking. After hardening in the presence of a hardener, they impart hardness properties to the composite material. The resins are also colorless after hardening. In other words, they do not alter the color or appearance of the particles within the resin after curing.

[0013] In the absence of a hardener, the composite resin is in the form of a more or less liquid paste.

[0014] The resin or thermoplastic polymer is chosen to have an optical transmission coefficient greater than 80% so that the visual appearance of the dial tends to resemble that of a precious stone as closely as possible.

[0015] The reflective particles added to the first resin help to increase the dial's refractive index and enhance its reflectivity, thus bringing its appearance closer to that of a precious stone. These reflective particles represent between 0.001% and 5% by weight of the first resin, and preferably between 0.02% and 1%.

[0016] The particles can have any type of geometric shape, for example a spherical, parallelepiped, cylindrical or oval shape, and have a size between 1µm and 100µm.

[0017] The particles can be chosen from phosphorescent, fluorescent, metallic, precious, semi-precious particles or a combination of these particles.

[0018] The particles can have any type of geometric shape, for example a spherical, parallelepiped, cylindrical or oval shape.

[0019] The particles can be chosen from phosphorescent, fluorescent, metallic, precious, semi-precious particles, mother-of-pearl particles or a combination of these particles.

[0020] According to one embodiment of the invention, the second resin comprises at least one additive selected from colorants, pigments, anti-UV agents or a combination of these additives.

[0021] The first part of the dial can be obtained via molding, injection, additive manufacturing or even via machining of a puck in thermoplastic or thermosetting material.

[0022] As can be seen in the figures, housing 11 of the first part 10 of the dial includes decorative elements 13, 14, 15 in positive relief; these decorative elements 13, 14, 15 can be indices, appliqués, logos or even geometric shapes.

[0023] These decorative elements are made to appear during the polishing of the dial or may be directly apparent in the case where a second transparent resin is poured into housing 11.

[0024] According to another embodiment illustrated in the figure 5 The dial may not include any decorative elements and may only present a surface with the appearance of a precious stone, i.e. a bright and / or sparkling appearance.

[0025] Thus, the invention also relates to a method for manufacturing a composite material comprising the following steps: form a first part 10 of the dial 1 in a first resin loaded with reflective particles, the first part forming a housing 11; pour at least a second resin into the housing 11 to form a second part 12 of the dial and obtain a dial 1; polish totally or selectively the dial 1 to reveal the first resin comprising the reflective particles.

[0026] The resin and reflective particles are generally in paste form; this mixture can be homogenized by passing it through a grinder. Grinding homogenizes the mixture and also breaks up any aggregates formed by the particles in the resin.

[0027] The formation of the resin, with or without hardener, generally results in the incorporation of air bubbles into the paste.

[0028] Therefore, to eliminate these air bubbles, the process may include a gas removal step. This step can advantageously be carried out using a centrifuge or a planetary centrifuge / mixer with a partial vacuum.

[0029] Depending on the requirements, at least one hardener can be added to the resin. As already mentioned, this hardener enables the polymerization and / or crosslinking of the resin.

[0030] After the hardener has been added, the mixture can be homogenized using a propeller mixer, for example.

[0031] Once the mixture is prepared, the resin can be poured or injected to form the first part of the dial.

[0032] According to a particular embodiment, the first part of the dial is placed in a vacuum chamber, thus simultaneously ensuring the removal of air and the shaping of the resin.

[0033] The mold can optionally be heated, the increase in temperature making the resin more fluid and accelerating the hardening of the resin.

[0034] Next, a second resin containing one or more additives such as colorants, pigments, anti-UV agents is prepared in a similar way to the first resin.

[0035] This second resin is poured into the housing of the first part of the dial, so as to fill the housing totally or partially and form a dial.

[0036] According to a particular embodiment, several resins of different compositions can be poured into the housing. The resins can be poured one on top of the other or poured locally into compartments of the housing.

[0037] The second resin or one of the additional resins can be transparent to add a three-dimensional effect to the dial.

[0038] Finally, the dial is polished either fully or selectively to reveal the first layer of resin containing the reflective particles on the visible / observable face of the dial.

[0039] The present invention also relates to a dial shaped by means of the process according to the invention.

Claims

1. Method for manufacturing a dial (1) characterized in that It includes the following steps: - forming a first part (10) of the dial in a first resin loaded with reflective particles, the first part forming a housing (11); - pouring at least a second resin into the housing to form a second part of the dial (12) and obtain a dial (1); - polishing totally or selectively the dial (1) to reveal the first resin containing the reflective particles.

2. A method according to claim 1, wherein the first resin is a thermoplastic resin, an epoxy resin or a polyurethane resin, and the second resin is an epoxy resin or a polyurethane resin.

3. A method according to any one of claims 1 or 2, wherein the reflective particles are selected from phosphorescent, fluorescent, metallic, precious, semi-precious particles or a combination of these particles.

4. A method according to any one of the preceding claims, wherein the second resin comprises at least one additive selected from colorants, pigments, anti-UV agents or a combination of these additives.

5. A method according to any one of the preceding claims, wherein several resins are poured into the housing of the first part of the dial.

6. A method according to any one of the preceding claims, wherein the second resin is poured into the housing of the first dial part so as to partially fill the housing.

7. A method according to any one of the preceding claims, wherein the charge of reflective particles integrated into the first resin is between 0.001% and 5%.

8. A method according to any one of the preceding claims, wherein the charge of reflective particles integrated into the first resin is between 0.02% and 1%.

9. A method according to any one of the preceding claims, wherein the housing (11) comprises decorative elements (13, 14, 15) in positive relief.

10. Method according to claim 9, wherein decorative elements (13, 14, 15) are indexes, appliques, logos or geometric shapes.

11. Dial (100) made by a process according to any one of claims 1 to 10.

Images