FR3067030A1 - DEVICE AND METHOD FOR PRODUCING AN OBJECT - Google Patents

Abstract

Device (100) for producing an object, comprising at least: a layer (102) of photocrosslinkable material comprising at least one polymer precursor having at least one function capable of reacting with at least one photoinitiator mixed with the polymer precursor , the photoinitiator being able to trigger a polymerization of the photocrosslinkable material during an exposure of the photocrosslinkable material to a light comprising at least one wavelength of the visible range; a protective case (106) in which the photocurable material layer is disposed and which is opaque or reflective of at least said wavelength.

Description

The invention relates to the field of production of polymer-based objects, and in particular stencils, masks or stamps, and in particular a device allowing the production of a polymer object, as well as a method for producing 'an object from such a device. The invention advantageously applies to the production of stencils and / or masks and / or stamps intended for producing shapes and / or drawings and / or text on any type of support: paper, walls, furniture, nails, skin, lips, etc.

A mask or a stencil is an element intended to be placed on a support and comprising one or more solid parts and one or more hollowed out parts through which a product (for example an ink, a cosmetic product, etc.) is intended to be applied. The product is then applied to the support according to a pattern defined by the solid part or parts and the recessed part or parts of the mask or the stencil. The pattern intended to be represented by the product is therefore defined negatively by the mask or the stencil.

A pad is an element making it possible to apply a product to a support in a pattern defined in a positive manner by one or more solid parts of the pad which apply the product directly to the support.

To make a stencil or a mask, manual work, sometimes important, of drawing and cutting is necessary. The quality of the stencil or mask produced therefore essentially depends on the skill of the person making it.

Professional tools, such as laser cutting tools, can be used to obtain a good quality stencil or mask. However, such tools are not intended for the general public because of their cost.

There are also tools intended for the general public to cut stencils and masks. However, the shapes that can be obtained are not customizable.

Similar problems are also found for the production of stamps, and more generally of objects of substantially flat shapes.

STATEMENT OF THE INVENTION

An object of the present invention is to provide a device allowing the production, individually, of an object, with a personalized pattern, which is accessible to the general public, at low cost and with excellent quality / precision whatever the skill of the user.

For this, the invention provides a device for the production of an object, comprising at least:

a layer of photocrosslinkable material comprising at least one polymer precursor having at least one function capable of reacting with at least one photoinitiator mixed with the polymer precursor, the photoinitiator being capable of triggering a polymerization of the photocrosslinkable material during exposure of the material photocrosslinkable with light comprising at least one wavelength of the visible domain;

- A protective case in which is placed the layer of photocrosslinkable material and which is opaque or reflective with respect to at least said wavelength.

The invention therefore provides a device incorporating a layer of photocrosslinkable material incorporating a photoinitiator making it possible, when exposed to at least one wavelength of the visible range, to trigger the phenomenon of photocrosslinking, here polymerization. The regions of the photocrosslinkable material exposed to this wavelength then transform into regions of polymeric material forming the solid parts of the object produced.

The protective case makes it possible to avoid triggering the polymerization phenomenon before a desired exposure of the photocrosslinkable material to the wavelength (s) capable of triggering the polymerization.

This device is particularly suitable for being able to be applied to a screen forming the light source triggering the polymerization. Thus, the pattern of the object produced can correspond to the pattern displayed on this screen during the polymerization phase. An object such as a mask and / or a stencil and / or a pad of high precision can thus be produced, and this without having to use expensive and / or bulky and / or dedicated professional tools (not personalized).

In addition, when the object produced corresponds to a stencil and / or a mask and / or a pad, it is compatible with very many ink or paint dispensing systems, for example of the ink pad type.

Compared to irradiation with a wavelength of the UV domain, the use of a wavelength of the visible domain to trigger the polymerization of the photocrosslinkable material allows rapid irradiation of the layer of photocrosslinkable material even when this layer is thick. The photons of the visible domain are those emitted by the screen with which the photocrosslinking can be implemented.

For example, for a layer about 3 cm thick, a very short exposure time may suffice if the photocrosslinkable material is previously partially polymerized.

The expression “mask and / or stencil and / or pad” is used to define the fact that the object produced may correspond to a mask, or to a stencil, or to a pad, or to an element having several parts each forming a mask or a stencil or a tampon, these parts being for example arranged one next to the other.

In general, the object produced has a substantially planar shape, with a thickness for example of between approximately 1 mm and 30 mm. This object may for example correspond to an earring, or else an object intended to be painted, glued, or decorated.

The polymer precursor can be of the acrylate and / or polysaturated acrylate and / or silicone acrylate and / or methacrylate, and / or polyurethane type with at least one acrylate and / or methacrylate and / or isocyanate function (for example 2isocyanatoethyl methacrylate), and / or the photoinitiator can comprise at least camphorquinone and / or thioxanthone, associated with at least one amino co-initiator. The amino co-initiator can for example comprise 2- (dimethylamino) -methacrylate and / or L-arginine and / or N-phenylglycine.

Compared to a photo-crosslinking carried out with UV light, the use of a light of the visible range to carry out the photo-crosslinking is much safer for the user or the people being in the vicinity of the device during this photo. -crosslinking, in particular to avoid damaging the eyes of this or these people. To further improve the safety of the person using the device when exposing the photocrosslinkable material to light and of any other people in the vicinity of the device, the photoinitiator can be chosen from those activatable by one or more lengths of 'visible domain wave and greater than about 400 nm, preferably greater than about 420 nm. For example, camphorquinone associated with at least one amino co-initiator can be activated with a wavelength between approximately 470 nm and 490 nm, and thioxanthone associated with at least one amino co-initiator can be activated with a length of wave between about 420 nm and 450 nm.

The photocrosslinkable material can comprise at least one solvent comprising methyl ethyl ketone and / or acetone and / or isopropyl acetate and / or butyl ethyl acetate and / or dichloromethane and / or chloroform.

The photocrosslinkable material can be partially polymerized. This makes it possible to shorten the duration of exposure of the photocrosslinkable material necessary for the production of the object. This also makes it possible to increase the viscosity of the photocrosslinkable material (for example at least 400 cp), which makes it more easily manipulated during the production of the device.

Advantageously, the photocrosslinkable material can be in the solid state at ambient pressure (approximately 10 ⁵ Pa) and at ambient temperature (approximately

25 ° C) or less than or equal to about 80 ° C. In the protective case, such a layer of photocrosslinkable material in the solid state is easy to handle, flexible and is not fragile.

When the object produced corresponds to a mask and / or a stencil and / or a tampon, the main function of the mask and / or of the stencil and / or of the tampon obtained is to be able to reproduce a pattern, for example a lip imprint, with maximum detail. When the element produced corresponds to a pad, it is possible that the pad obtained has an additional function of sponge and / or reservoir type with respect to a product intended to be applied via this pad, for example example for the application of a cosmetic product such as a lipstick or of ink, so that this pad forms an element for applying this product of the ink pad type. Thus, after the crosslinking of the photocrosslinkable material, the pad obtained can be “loaded”, or soaked, with product to be deposited. For this, the layer of photocrosslinkable material can comprise at least one non-crosslinkable blowing agent. With such a pore-forming agent present in the photocrosslinkable material, pores are formed within the polymer obtained, these pores then serving as a reservoir of product to be applied. This can also apply for objects other than stamps.

The blowing agent is, for example, water-soluble and can thus be removed after the photo-polymerization of the photocrosslinkable material, for example by a step of rinsing with water the polymer obtained. The blowing agent is for example of a polymeric nature and may comprise PVA and / or PVP and / or polyalkyloxazoline and / or PEG and / or hydroxycellulose and / or sugar.

The fact of initiating the polymerization of the photocrosslinkable material with one or more wavelengths of the visible range makes it possible to introduce the pore-forming agent into the photocrosslinkable material without having to agree on refractive indices.

The blowing agent is advantageously soluble in a chlorinated solvent and can be mixed with the acrylate, methacrylate and or silicone acrylate and methacrylate bases of the photocrosslinkable material during the manufacture of the layer of photocrosslinkable material.

The presence of the blowing agent in the photocrosslinkable material also makes it possible to facilitate the demolding of the polymer obtained due to the flexibility conferred by the presence of the pores in the polymer.

In order to limit the impact on the mechanical strength of the object produced, the concentration of the blowing agent in the photocrosslinkable material is preferably less than or equal to approximately 10% of the total mass of the photocrosslinkable material. The size of the pores and the continuity of the porous network obtained can be modulated by the molecular weight of the pore-forming agent used.

After the crosslinking of the photocrosslinkable material, a step of rinsing the polymer makes it possible to eliminate the by-products resulting from the photoactivation (photoactivators and associated catalysts) and the blowing agent (s) possibly present, thus allowing safe contact of the polymer with the skin and mucous membranes. However, the photoinitiators and the possible blowing agent (s) are advantageously chosen as being non-toxic so that only partial cleaning or non-cleaning of the object obtained at the end of the crosslinking is not toxic.

In addition, it is possible to provide that a product then used with the object obtained comprises chemical compounds making it possible to remove the particles of photocrosslinkable material which have not been polymerized and which, when they are not water-soluble, are not removed by rinsing with pure water.

The layer of photocrosslinkable material can have a thickness of between approximately 1 mm and 30 mm.

The protective case may include at least one metallic layer capable of reflecting at least said wavelength. This metal layer has for example a thickness greater than or equal to about 100 nm, and advantageously comprises aluminum.

The device may also comprise a layer of material which is transparent with respect to at least said wavelength and which is arranged such that it passes through the light when the photocrosslinkable material is exposed to this light.

The layer of transparent material can thus form a protective layer between the layer of photocrosslinkable material and the light source used for the polymerization of the photocrosslinkable material.

The layer of transparent material can in particular serve to protect the screen serving as a light source during the exposure of the layer of photocrosslinkable material facing this screen (the layer of transparent material being intended to be placed between the screen and the layer of photocrosslinkable material during this exposure).

The expression “transparent with respect to at least said wavelength” means that at least part of the light, for example at least 80% and advantageously approximately 100% of the light, at this length d wave can pass through the layer of transparent material. The greater the transparency of this layer with respect to the wavelength (s) used for the polymerization of the photocrosslinkable material, the greater the duration of exposure of the photocrosslinkable material to this or these wavelengths will be reduced in order to obtain the object.

At least one inner face of the protective case opposite which the layer of photocrosslinkable material is disposed can form an optically reflecting face at least with respect to said wavelength. Such a reflective inner face makes it possible to reduce the duration of exposure of the photocrosslinkable material to this wavelength to form the object.

The expression “optically reflecting face at least with respect to said wavelength” means that this face is capable of reflecting at least 50% of the light at this wavelength, and returning it to the photocrosslinkable material . The reflection rate of this face can be adapted as a function of the thickness of the layer of photocrosslinkable material as well as the maximum duration of irradiation to which the photocrosslinkable material is intended to be exposed.

The protective case may include a front part (at the level of which the light source is intended to be arranged) and / or a removable rear part. A removable front part of the protective case can thus be easily removed when the exposure of the photocrosslinkable material to the polymerization wavelength must begin. A removable rear part of the protective case can thus be easily removed when the crosslinking of the photocrosslinkable material is complete, and allows easy access to the object produced from the rear of the device, which allows for example to pour a rinse aid directly on the object obtained from the back of the protective case.

The device may further comprise an opaque or reflective hermetic packaging vis-à-vis at least said wavelength and in which are disposed at least the layer of photocrosslinkable material and the protective case. Such hermetic packaging makes it possible for example to store the photocrosslinkable material for several months under vacuum or in a protective atmosphere before its use.

The invention also relates to a method for producing an object, comprising at least the implementation of the following steps:

- Installation of a device as described above facing at least one screen of an electronic device such that the layer of photocrosslinkable material is exposed vis-à-vis the screen;

display by the screen, for a predetermined duration, of a crosslinking image comprising one or more first zones and one or more second zones such that said wavelength is emitted only from the second zone or zones and that only the or the parts of the layer of photocrosslinkable material arranged opposite the second zone or zones are polymerized, thus forming the object.

This method therefore proposes using a screen, for example that of a smartphone, a computer tablet, a computer or even a television, serving as a controlled light source for polymerizing a pattern in a photosensitive material and obtaining an object whose contours and / or patterns are precisely defined by differentiating between the first and second zones of the crosslinking image, the wavelength triggering the crosslinking being emitted only from the second zone or zones. The pattern is transferred to the photosensitive material directly through the screen that displays this pattern. Thus, the result obtained does not depend on the skill of the user because this process does not use manual tools to achieve this object. This process is simple, easy to implement for the user and inexpensive.

The time during which the image is displayed on the screen corresponds to the time during which the photocrosslinkable material is polymerized, or crosslinked. This duration is predetermined because it corresponds to a duration greater than or equal to the duration making it possible to polymerize the parts of the layer of photocrosslinkable material receiving said wavelength. This duration can be fixed or variable depending on the thickness of the layer of photocrosslinkable material, the desired hardness or the precision of the pattern produced. This duration also depends on the density of the photon flux emitted by the screen.

The crosslinking image comprises one or more first zones which correspond for example to black zones of the image, from which said wavelength triggering the polymerization is not emitted. The crosslinking image also comprises one or more second zones, clear or colored, and for example of white or blue color, such that only the part or parts of the layer of photocrosslinkable material placed facing this or these second zones are entirely polymerized

The protective case of the device may include a removable front part which can be removed after having put the device against the screen. A tab accessible from outside the case can for example be used to remove this removable front part.

The method can also include, prior to the display of the crosslinking image on the screen, the implementation of steps of:

- creation or loading, in the electronic device, of a preliminary image, corresponding for example to a photograph and / or a drawing, from which the object is intended to be produced;

- digital processing creating the crosslinking image from the preliminary image.

The creation of the preliminary image corresponds for example to the taking of a photograph from a camera integrated into the electronic device. The loading of the preliminary image into the electronic device corresponds for example to a downloading of this preliminary image into a storage memory of the electronic device or associated with the electronic device.

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The protective case of the device may include a removable rear part which is removed after the display of the crosslinking image by the screen, forming access to the object from outside the device.

The invention can be applied, for example, to the field of makeup, in particular for producing a mask and / or a stencil and / or a pad used for applying a cosmetic product such as lipstick, to the field of permanent or temporary tattooing, in the medical field for example to provide personalized protection for treatments such as laser treatments or for the application of liquid nitrogen, in the field of decoration for making stencils used to draw patterns, or in the field of painting or repair vehicle body.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the description of exemplary embodiments given purely by way of indication and in no way limiting, with reference to the appended drawings in which:

- Figure 1 schematically shows a device, object of the present invention, according to a particular embodiment;

- Figure 2 shows the flowchart of a method of making an object, object of the present invention, according to a particular embodiment;

- Figures 3A and 3B respectively represent a preliminary image and a crosslinking image used during a method of producing an object, object of the present invention, according to the particular embodiment;

- Figure 4 shows a stencil obtained by implementing an embodiment process, object of the present invention, according to the particular embodiment;

- Figure 5 shows a device type applicator pad in which a stencil, made from the device according to the invention, is used.

Identical, similar or equivalent parts of the different figures described below have the same reference numerals so as to facilitate the passage from one figure to another.

The different parts shown in the figures are not necessarily shown on a uniform scale, to make the figures more readable.

The different possibilities (variants and embodiments) must be understood as not being mutually exclusive and can be combined with one another.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

First of all, reference is made to FIG. 1 which schematically represents a device 100 for producing an object, according to a particular embodiment.

The device 100 comprises a layer 102 of photocrosslinkable material from which the object is intended to be produced.

The photocrosslinkable material comprises at least one polymer precursor having at least one function that can be activated by at least one photoinitiator, as well as the photoinitiator allowing the polymerization of the precursor during its exposure to light including at least one wavelength of the visible domain. The photocrosslinkable material is produced in the form of an advantageously homogeneous mixture of the polymer precursors with the photoinitiator, this mixture being produced without being exposed to or to the wavelengths to which the photoinitiator reacts, for example in the dark or under a light neutral.

By precursors of the polymeric material is meant monomers and / or oligomers and / or pre-polymers leading to the formation of the polymer, for example of the acrylate and / or polysaturated acrylate and / or silicone acrylate and / or methacrylate and / type. or isocyanate, and / or polyurethane with at least one acrylate and / or methacrylate function. For example, these precursors comprise poly (ethylene glycol) methacrylate and / or poly (propylene glycol) dimethylacrylate and / or poly (propylene glycol) diacrylate and / or poly (ethylene glycol) acrylate and / or polysiloxane acrylate and / or methacrylate.

The photoinitiator is here able to be active or activated by the wavelengths of visible light, that is to say when it is exposed to at least one wavelength between approximately 400 nm and 750 nm, so that the phenomenon of polymerization of the photocrosslinkable material occurs when the photocrosslinkable material is exposed to visible light. Alternatively, this photoinitiator can be active when exposed to only part, or at least one wavelength, of the visible range.

The photoinitiator is chosen such that it catalyzes the crosslinking of the polymer precursor during an excitation in the visible range and for one or more wavelengths capable of being emitted by a screen such as a smartphone screen, or 'a tablet, or a computer, or even a television. Advantageously, the photoinitiator is chosen such that the crosslinking of the material of the layer 102 produces on exposure of the photocrosslinkable material to the most energetic wavelengths among those of the visible spectrum, that is to say those corresponding to the blue or purple color (close to 400 nm). Such a photoinitiator is for example of the camphorquinone type which is very effective in the visible and very soluble in the solvent or solvents used for the production of the layer of photocrosslinkable material. Camphorquinones are associated with an amino co-initiator, preferably 2- (dimethylamino) methacrylate and / or L-arginine and / or Nphenylglycine. All these products are not toxic to the living. The activation range is between about 470 nm and 490 nm, which is very advantageous. It is also possible to use, as an amino co-initiator, thioxanthone which is also associated with at least one amino co-initiator such as one of those mentioned above. Such a co-initiator can be activated by wavelengths between approximately 420 nm and 450 nm.

By making the photocrosslinkable material, one or more mixed solvents are used. These solvents are chosen, for example, from methyl ethyl ketone, acetone, isopropyl acetate, or butyl and ethyl acetate. It is also possible to use chlorinated solvents such as dichloromethane and chloroform.

The proportion of solvents is such that these solvents represent between approximately 30% and 50% of the total mass of the photocrosslinkable material. These solvents are intended to be removed by drying or rinsing. Thus, the proportion of polymer precursors and photoinitiators (and any pore-forming agents as described below) used in the initial mixture of the photocrosslinkable material is between approximately 70% and 50%. Advantageously, the proportion of solvents is reduced as much as possible so that drying or rinsing is carried out as quickly as possible.

After drying, the photoinitiators are present in the photocrosslinkable material and represent between approximately 0.5% and 5% of the total mass of the photocrosslinkable material. When blowing agents are added (as described below), these agents can represent at most 10% of the total mass of the photocrosslinkable material. The rest of the total mass of the photocrosslinkable material is formed by the photocrosslinkable elements, namely the precursors of photocrosslinkable polymers forming between approximately 50% and 98%, and advantageously between approximately 95% and 98% for storage reasons, of the remainder of the total mass, and the complement of photocrosslinkable molecules. The photocrosslinkable molecules carry at least one crosslinkable function and serve to form the bonds within the polymer network. These molecules are for example trimethylol propane triacrylate, di (trimethylolpropane) tetracrylate, pentaerythritol tetracrylate, dipentaerythritolpenta- / hexaacrylate, trimethylolopropane propoxylate triacrylate, or also 1,6-hexanediol ethoxylate diacrylate.

Advantageously, the photocrosslinkable material of the layer 102 is already partially polymerized and / or crosslinked. Thus, during the production of the object, the time of exposure of this material to light is minimized to obtain the object. In addition, this makes it possible to increase the viscosity of this material so that it is in the form of a gel which is easy to handle and does not run when the device 100 is produced. This viscosity is preferably greater than or equal to about 400 cp (centipoise) or mPa.s.

Advantageously, it is also possible that the layer 102 is in the solid state at ambient pressure and at a temperature less than or equal to approximately

80 ° C. The flexibility of the layer 102 is adjusted inter alia via the concentration of the solvents used.

During the production of the device 100, the photocrosslinkable material is deposited so as to form the layer 102 having a thickness for example between approximately 1 mm and 30 mm, on a layer 104. This layer 104 is intended to be placed facing the 'screen which will be used to crosslink the material of layer 102. Thus, layer 104 is transparent at least vis-à-vis the wavelength (s) which will be used for this crosslinking. This layer 104 serves as a support for the photocrosslinkable material which is not solid and makes it possible in particular to protect the screen from this material which could stick to the screen or leave traces, and also makes it possible to pass the light excitation of the photoinitiator in order to trigger the polymerization reaction of the material of layer 102.

The layers 102 and 104 are placed in a protective case 106 surrounding these layers. This case 106 is opaque or reflective at least vis-à-vis the wavelength (s) triggering the crosslinking of the material of the layer 102, in order to protect this material until it is exposed to the light emitted by the screen. This case 106 can absorb or reflect the whole of the wavelength (s) triggering the crosslinking of the material of the layer 102

Alternatively, it is possible that the device 100 does not comprise the layer 104, in particular when the layer of photocrosslinkable material 102 is in the solid state. In this case, only the layer 102 can be placed in the protective case 106.

Advantageously, a rear portion 108 of this case 106 has an interior surface (facing which the layer 102 is arranged) reflecting at least vis-à-vis the wavelength (s) of the light used for the polymerization photocrosslinkable material. This makes it possible to accelerate the crosslinking which will be carried out subsequently. The counterpart is that for patterns of small dimensions, this light reflection can make the edges of these patterns less sharp.

This case 106 also allows precise positioning of the device

100 on the screen. In FIG. 1, the device 100 is shown arranged on a screen 202 of an electronic device 200 which corresponds for example to a smartphone. The case 106 comprises for example adhesive edges 110 allowing this precise positioning.

Before the device 100 is available on the screen 202, the face of the case 106 having the adhesive edges 110 can be protected by a protective film. This protective film can be removed just before positioning the device 100 on the screen 202.

The case 106 further comprises a lower part 112, that is to say that which is disposed between the screen 202 and the layer 104, which is removable, for example precut against the rest of the case 106. Thus, before and during the positioning of the device 100 on the screen 202, this lower part 112 protects the layer 104 from external light. After positioning the device 100 on the screen 202, this lower part 112 can be removed for example by means of a tongue 114 projecting from the case 106 and which is integral with the lower part 112. By pulling on the tongue 114, the lower part 112 can be detached from the rest of the case 106, thus exposing the layer 104 to the screen 202 while retaining the edges 110 of the case 106 which are in contact with the screen 202 and which prevents exposure from layer 102 to outside light.

This case 106 can also be such that the rear part 108 is easily detachable from the rest of the case so that, after the exposure of the photocrosslinkable material of the layer 102 to the light emitted from the screen 202, it either it is possible to easily remove the object obtained from the rear of the case 106, without damaging this object and without dirtying the screen 202, and / or pouring a rinsing liquid onto the object obtained from the rear of the case 106.

Before its use on the screen 202, the device 100 can be placed in an opaque or reflective hermetic packaging, for example sealed under vacuum or under a controlled atmosphere (for example without oxygen) in order to avoid any degradation (in particular drying) of the photocrosslinkable material of layer 102.

A method of producing an object implemented with the device 100 is described below in connection with FIG. 2. In the example described here, the object produced corresponds to a mask and / or a stencil and / or a tampon. In addition to the general description of this process, a particular example of this process is also described below, this particular example allowing the production of a stencil intended to be used for applying a cosmetic product to the lips of a person.

During a first step 302, a preliminary image is first of all created or loaded into the device 200. This preliminary image, corresponding for example to a photograph or a drawing, comprises a visual representation of the shape and dimensions of the object to be produced. This preliminary image can correspond to an image stored in the memory of the device 200. The preliminary image can also be downloaded by the device 200 from a database or other remote electronic equipment or from an external memory connected to the device 200. It is also possible that this preliminary image corresponds to a photograph taken by a camera integrated in the device 200.

According to the particular example of this method, this first step 302 can consist in taking a photograph, via an integrated photographic device of the device 200 which corresponds for example to a smartphone or a tablet, of the face of the person, and in particular of the lips, on which the cosmetic product will be applied. This photograph can more generally be a portrait or photographic self-portrait taken from the device 200. This photograph can also be downloaded or saved on the device 200. Advantageously, this photograph can be taken via an application or software loaded on the device 200 So that the dimensions of the lips or of the face appearing in the photograph correspond to the real dimensions of the lips of the person, it is possible that the photograph is taken by placing on the face of the person photographed a reference pattern, corresponding for example to a sticker, the dimensions of which allow the application or software to perform a calibration of the captured image. The shape of this sticker can be round or any other shape, the dimensions of which can be clearly determined by the application or software.

This calibration can be applied to other examples of implementation of this method and is not limited to the production of a stencil for applying a cosmetic product to lips. In addition, other means of calibrating the dimensions of any photographed object intended to serve as a model for the production of the object can be envisaged, such as for example the display of a template by the screen 202 of the device 200 during of photography.

The preliminary image can be retouched via the application or software before continuing the process. In the particular implementation example, this retouching can consist in modifying the contour of the lips, or in creating patterns (stripes, dots, etc.) on the lips so that these patterns stand out on the lips when the cosmetic product is applied through the stencil made from this preliminary image.

To achieve the object, a crosslinking image is created from the preliminary image, in which the regions or zones of the preliminary image intended to form the solid parts of the object are differentiated from those intended to form the parts. empty objects. For this, the application or the software can perform digital processing of the image making it possible to distinguish these different regions or zones (step 304). This digital processing can for example correspond to a transformation such that the regions of the preliminary image representing the parts of the object intended to be empty form first zones of the crosslinking image which are dark or black so that no light able to crosslink the material of layer 102 is emitted from these first areas of the crosslinking image and therefore that the photocrosslinkable material which will be located opposite these first areas is not polymerized. In addition, the regions of the preliminary image representing the parts of the object intended to be full form second zones of the crosslinking image which comprise at least one color other than black, for example white, so that light is emitted from these second zones of the crosslinking image and therefore that the photocrosslinkable material which will be located opposite these second zones is polymerized. This digital processing can correspond for example to a transformation of the initial image which is a two-color image, for example in black and white (without intermediate gray).

Advantageously, the second zone or regions of the crosslinking image can be blue in color (wavelength close to 400 nm) because blue light is the one for which the photons are the most energetic. This therefore makes it possible to reduce the duration of exposure of the photocrosslinkable material to the crosslinking image in order to completely polymerize the object.

By way of illustration of the particular example described here, FIG. 3A represents the photographed image of the lips of a user, which corresponds to a preliminary image 401 obtained using the camera of a smartphone. FIG. 3B represents a crosslinking image 403 obtained after the digital processing implemented from the preliminary image 401 of FIG. 3A. This crosslinking image 403 comprises a first black area 402 (corresponding to the lips photographed) representing the area of the screen 202 which will not emit light so as not to polymerize the photocrosslinkable material which will be located opposite this first area 402 , and a second white area 404 representing the area of the screen 202 which will emit light in order to polymerize the photocrosslinkable material located opposite this second area 404.

The device 100 is then placed on the screen 202, with the lower part 112 disposed against the screen 202 (step 306). For this, the device 100 is removed from the hermetic packaging. The protective film covering in particular the adhesive edges 110 is removed, then the device 100 is positioned against the screen 202. Finally, the removable lower part 112 is removed by pulling on the tongue 114.

The crosslinking, or polymerization, of the photocrosslinkable material can then begin by displaying by the screen 202, for a predetermined period, the crosslinking image 403 illuminating only the portions of photocrosslinkable material intended to be polymerized (step 308). Once this time has elapsed, the display of the crosslinking image 403 by the screen 202 can be stopped. The user is for example informed of the end of this crosslinking by an audible signal emitted by the device 200. This predetermined duration depends in particular on the thickness of the photocrosslinkable material, on the nature of this material as well as on the density of the flux of photons emitted by the screen 202.

The object formed by the parts of polymerized material of the layer 102 is then recovered (step 310). Access to this object is for example achieved by detaching the rear part 108 from the case 106. As a variant, the object can also be recovered by taking off the device 100 from the device 200, and by removing the layer 104.

In the particular example of implementation described here, a stencil 406 obtained from the crosslinking image 403 is shown in FIG. 4. This stencil 406 comprises portions of polymer material 408 formed by exposure to the light emitted from the second zone 404 of the crosslinking image 403, and one or more empty zones 410 (only one in FIG. 4) obtained thanks to the absence of emission of visible light from the first zone 402, through which the cosmetic product is intended to be applied.

The object produced is preferably rinsed under water and / or dried in order to remove the non-polymerized photocrosslinkable material, that is to say the parts of material of the layer 102 not exposed to the light emitted by the screen 202, and solvents.

When the object corresponds to a mask and / or a stencil and / or a pad, it can then be used either directly by placing it on the surface to be treated, or by inserting it into a device of the ink pad type making it possible to apply ink or any other product stored in the ink pad device, through this mask and / or this stencil.

In the particular example of implementation described here, the stencil 406 is placed in a device 500 forming a product applicator on the lips, as for example shown in FIG. 5. Thus, the stencil 406 obtained has a rear face disposed against an element 502 loaded with product, for example a cosmetic product such as lipstick. The stencil 406 is curved and held in the device 500 by a support 504 bearing on the stencil 406.

The method and the device 100 described above allow the production of an object advantageously corresponding to a mask and / or a stencil. As a variant, it is possible to implement this method with the device 100 so that the polymerized material does not form a stencil and / or mask, but a pad. In this case, the crosslinking image which is created is such that the pattern of this image is defined positively by the solid parts of the pad which are intended to apply the product directly to the support. This can also apply for the production of objects other than stamps.

Using the example previously described in connection with FIGS. 3A to 3C, if the tampon is intended for applying a cosmetic product to the lips of the user, the crosslinking image in this case comprises an area which will not emit light in order not to polymerize the photocrosslinkable material which will be located opposite this zone and which corresponds to the zone designated by the reference 404 in FIG. 3B, and the zone intended to emit light in order to polymerize the photocrosslinkable material located opposite this zone corresponds to that designated by the reference 402.

When the device 100 is intended for producing a tampon, it is possible that the layer 102 of photocrosslinkable material comprises non-crosslinkable pore-forming agents which, at the end of the crosslinking step, will form pores within the polymer element obtained. Thus, the stamp produced can be loaded with the product intended to be applied by this stamp, such as for example lipstick or ink.

The blowing agent is for example water-soluble and can thus be removed after the polymerization by a step of rinsing with water the polymer obtained. The blowing agent is for example of a polymeric nature and may comprise PVA and / or PVP and / or polyalkyloxazoline and / or PEG and / or hydroxycellulose and / or sugar.

Claims (15)

1. Device (100) for producing an object (406), comprising at least: a layer (102) of photocrosslinkable material comprising at least one polymer precursor having at least one function capable of reacting with at least one photoinitiator mixed with the polymer precursor, the photoinitiator being capable of triggering a polymerization of the photocrosslinkable material during a exposing the photocrosslinkable material to light comprising at least one wavelength of the visible domain; - A protective case (106) in which is placed the layer (102) of photocrosslinkable material and which is opaque or reflective with respect to at least said wavelength. 2. Device (100) according to claim 1, in which the layer (102) of photocrosslinkable material has a thickness of between approximately 1 mm and 30 mm. 3. Device (100) according to one of the preceding claims, in which the polymer precursor is of the acrylate and / or polysaturated acrylate and / or silicone acrylate and / or methacrylate and / or isocyanate, and / or polyurethane type with at least an acrylate and / or methacrylate function, and / or in which the photoinitiator comprises at least camphorquinone and / or thioxanthone, associated with at least one amino co-initiator. 4. Device (100) according to one of the preceding claims, wherein the photocrosslinkable material is partially polymerized and / or in the solid state at ambient pressure and at a temperature less than or equal to about 80 ° C. 5. Device (100) according to one of the preceding claims, in which the layer (102) of photocrosslinkable material also comprises at least one non-crosslinkable blowing agent. 6. Device (100) according to one of the preceding claims, in which the protective case (106) comprises at least one metal layer capable of reflecting at least said wavelength. 7. Device (100) according to one of the preceding claims, further comprising a layer (104) of transparent material vis-à-vis at least said wavelength and arranged such that it passes through the light upon exposure of the photocrosslinkable material to this light. 8. Device (100) according to one of the preceding claims, in which at least one inner face of the protective case (106) opposite which the layer (102) of photocrosslinkable material is disposed forms an optically reflective face at less with respect to said wavelength. 9. Device (100) according to one of the preceding claims, wherein the protective case (106) comprises a front part (112) and / or a rear part (108) removable. 10. Device (100) according to one of the preceding claims, further comprising an opaque hermetic packaging or reflective with respect to at least said wavelength and in which are arranged at least the layer (102) of photocrosslinkable material and the protective case (106). 11. Method for producing an object (406), comprising at least the implementation of the following steps: - Installation (306) of a device (100) according to one of claims 1 to 9 opposite at least one screen (202) of an electronic device (200) such as the layer (102) of photocrosslinkable material is exposed vis-à-vis the screen (202); - Display (308) by the screen (202), for a predetermined period, of a crosslinking image (403) comprising one or more first zones (402) and one or more second zones (404) such that said length d wave is emitted only from the second zone (s) (404) and only the part or parts of the layer (102) of photocrosslinkable material arranged opposite the second zone (s) (404) are polymerized, thus forming the object (406). 12. The method of claim 11, wherein the protective case (106) of the device (100) comprises a removable front part (112) which is removed after having put the device (100) against the screen (202) ). 13. Method according to one of claims 11 or 12, further comprising, before the display of the crosslinking image (403) by the screen (202), the implementation of steps of: - Creation or loading (302), in the electronic device (200), of a preliminary image (401) from which the object (406) is intended to be produced; - digital processing (304) creating the crosslinking image (403) from the preliminary image (401). 14. Method according to one of claims 11 to 13, wherein the protective case (106) of the device (100) has a removable rear part (108) which is removed after the display of the crosslinking image ( 403) during the predetermined duration, forming an access to the object (406) from outside the device (100). 15. Method according to one of claims 11 to 14, wherein the object (406) produced corresponds to a mask and / or a stencil and / or a tampon.