Device for applying a liquid, as well as applicator, cosmetic assembly and associated manufacturing process

Abstract

Device for applying a liquid, together with applicator, cosmetic assembly and associated manufacturing process. Device (10) for applying a liquid, comprising a body (12) made of silicone, the body (12) including both a liquid-proof silicone skin (17) and a silicone core (18) with an alveolar structure adapted to absorb the liquid. The core (18) is formed from the material with the skin (17) and is covered by the skin (17) except for a free face (21) of the core (18) adapted to deposit and spread the liquid. Figure for the abbreviation: Figure 2

Description

Title of the invention: Device for applying a liquid, as well as associated applicator, cosmetic assembly and manufacturing method

[0001] The present invention relates to a device for applying a liquid. It also relates to an applicator comprising such a device. It also relates to a cosmetic assembly comprising such an applicator. It further relates to a method of manufacturing such a device.

[0002] Liquids, in particular cosmetic liquids, are usually applied by devices flocked over all or part of their surface. Flocking consists of applying a flock, typically gluing fibers, to a support, and allows the applicator device to absorb a small amount of liquid, in order to deposit it on a surface, for example on the skin, and to spread it, or to smooth it, without removing it from the surface. Thus, it is possible to apply the liquid in several passes without waiting for it to dry. However, the flock is easily contaminated by microorganisms, in particular bacteria. Thus, flocked devices used to apply liquids have a limited lifespan, in particular if they are in regular contact with the skin.

[0003] The aim of the invention is then to propose a new device for applying a liquid, which, while being at least as effective as flocked devices for applying the liquid, is less subject to the risk of contamination.

[0004] To this end, the invention relates to a device for applying a liquid, comprising a body made of silicone, the body including both a liquid-tight silicone skin and a silicone core with a honeycomb structure adapted to absorb the liquid, the core being integral with the skin and being covered by the skin except at a free face of the core adapted to deposit and spread the liquid.

[0005] Thanks to the invention, the device can be used to apply a liquid to a surface to be covered, and to spread it without successive passes of the device removing it from the surface to be covered, while limiting the risks of contamination by microorganisms. Indeed, the alveolar structure of the core of the device makes it possible to absorb a small quantity of liquid, which then makes it possible to apply it to the surface to be covered. This structure also makes it possible to spread and smooth the liquid without removing it from the surface to be covered on which it has been applied.

[0006] The material used for this device, namely silicone, is an antimicrobial material. Thus, its use limits the risks of contamination by microorganisms. The free face revealing the alveolar structure allows the absorption of the liquid by the device, and the presence of the skin facilitates the application of the liquid, which can only be applied when the surface to be covered is in contact with the free face. This allows for precise application of the liquid, compatible for example with the deposition of ink on paper, or makeup, for example on the lips of a user. In addition, silicone is a biocompatible material, which is therefore suitable for use where it is in contact with the epidermis or the lips of a user.

[0007] According to other advantageous aspects of the invention, the device comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0008] - The body is cylindrical in shape along a central axis.

[0009] - The free face is beveled relative to the central axis.

[0010] - The silicone includes an additive.

[0011] - The additive is antibacterial.

[0012] The invention also relates to an applicator, comprising the device described above and a gripping support on which the device is fixed.

[0013] According to other advantageous aspects of the invention, the applicator comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0014] - The body includes an extension which is inserted into the gripping support in order to fix the device to the gripping support.

[0015] The invention also relates to a cosmetic assembly comprising the applicator described above and a reservoir, containing a cosmetic liquid, the device being adapted to be inserted into the reservoir to bring the free face into contact with the cosmetic liquid.

[0016] The invention also relates to a method of manufacturing the device described above, comprising: - a step of mixing a liquid silicone rubber with a blowing agent to form a liquid silicone rubber mixture; - a step of injecting the mixture into a mold heated to a temperature greater than or equal to a first temperature threshold; - a step of crosslinking an outer layer of the mixture, in order to form an outer part of a part; - a step of heating an inner layer of the mixture; - a stage of expansion of the blowing agent, when the blowing agent reaches a temperature above a second temperature threshold, then forming alveoli in the inner layer of the mixture; - a step of crosslinking the inner layer to form an in-

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] interior of the room; and - a step of conforming the part to form the device and make the free face visible, the outer part of the part forming the skin and the inner part forming the core. According to other advantageous aspects of the invention, the method comprises one or more of the following characteristics, taken individually or in all technically possible combinations: - The shaping step includes cutting the part to form the body, a cut section formed during cutting defining the free face. The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: - [Fig.l] [Fig.l] is an elevation view of a device according to one embodiment of the invention; - [Fig.2] [Fig.2] is a perspective view of the device of [Fig.l]; and - [Fig.3] [Fig.3] is an elevation view of a cosmetic set comprising the device of [Fig.l]. Figures 1 and 2 show a device 10 suitable for applying a liquid, and in particular for depositing and spreading or smoothing it on a surface to be covered. The liquid may be a cosmetic liquid, in particular a gloss, but may also be an ink, a paint, or any other type of liquid. The device 10 comprises a silicone body 12, that is to say that the body 12 is made of a silicone. The body 12 here has a cylindrical shape, which extends along a central axis X12 and which, for reasons which will appear later, is beveled at one of its two axial ends. The body 12 includes a skin 17 and a core 18, visible in dotted lines in [Fig.l], made of a single material with the skin 17. The silicone of the skin 17 has a structure making it impermeable to the liquid to be applied. This structure of the silicone of the skin 17 is in particular a solid structure, the entire volume of which is continuously occupied by the silicone. The silicone of the core 18 has a honeycomb structure, that is to say that the core 18 comprises cells, unlike the skin 17. The cells of the core 18 are open cells, that is to say that they communicate with each other, thus jointly forming a network of cavities in free fluid communication with each other. When the core 18 is brought into contact with the liquid to be applied, the liquid is advantageously distributed throughout the core 18 because the cells communicate with each other. In all cases, the cells are adapted to absorb the liquid and the heart 18 can therefore accumulate fluid.

[0025] In practice, the size and number of cells in the core 18 is such that the core 18 has a high porosity, greater than the porosity of the skin 17.

[0026] As clearly visible in Figures 1 and 2, the core 18 is completely covered by the skin 17, with the exception of a free face 21 of the core 18, which is left exposed. Thus, the alveolar structure of the core 18 is visible from the free face 21. The liquid only penetrates into the core 18 from the free face 21, and likewise, it is only deposited on the surface to be covered through the free face 21, the skin 17 preventing the liquid from penetrating into and exiting the core 18 anywhere other than through the free face 21.

[0027] Advantageously and as shown in Figures 1 and 2, the free face 21 is beveled relative to the central axis X12, that is to say it is flat and inclined relative to the central axis X12. For example, the free face 21 forms an angle of 30 degrees with the central axis X12. In particular, the free face 21 is thus arranged at the beveled axial end of the body 12. This geometry is particularly advantageous in the case where the device 10 is used to apply cosmetic liquid, and in particular gloss, to the lips of a user.

[0028] In the embodiment illustrated in Figures 1 and 2, the device 10 also comprises an extension 14, which extends from the body 12. This extension 14 advantageously extends along the central axis X12 from one end of the body 12, axially opposite the free face 21.

[0029] Advantageously, the extension 14 is made of the same material as the body 12, thus being made of the same silicone as the body 12.

[0030] [Fig. 3] represents a cosmetic assembly 30, comprising an applicator 31 and a reservoir 32. The cosmetic assembly 30 is adapted for the user to apply a cosmetic liquid, for example gloss to his lips.

[0031] The applicator 31 comprises the device 10, as well as a gripping support 35 on which the device 10 is fixed. The gripping support 35 here comprises a rod 36 and a gripping end piece 37, the rod 36 and the gripping end piece 37 being fixedly secured to each other. The gripping end piece 37 is optional. Advantageously, the device 10 is fixed to the rod 36 by means of the extension 14, which is inserted into the rod 36, the rod 36 being for example hollow at one of its longitudinal ends. The extension 14 is for example glued and / or force-fitted into the rod 36. The gripping end piece 37 is adapted to be held by the user, in particular by being grasped by the fingers of one of the latter's hands.

[0032] The reservoir 32 contains the cosmetic liquid and allows the device 10 to be inserted therein by the user, by manipulating the applicator 31 by its gripping tip 37. In this case, a part of the rod 36 is also inserted into the reservoir 32. When the device 10, more particularly when the free face 21, is in contact with the liquid, a fraction of the liquid is absorbed by the core 18. The user then removes the device 10 from the reservoir 32 and brings the free face 21 into contact with the surface to be covered, here the user's lips. By sliding the free face 21 along the user's lips, the cosmetic liquid, here gloss, is thus deposited and smoothed onto the user's lips.

[0033] Particularly advantageously, the gripping end piece 37 also serves as a stopper for the reservoir 32. For example, when the device 10 and the rod 36 are inserted into the reservoir 32, the gripping end piece 37 can be screwed or snapped onto the reservoir 32, and thus seal the reservoir 32.

[0034] A method of manufacturing the device 10 is described below.

[0035] The silicone from which the device 10 is formed is formed from liquid silicone rubber, or LSR, which is molded and then crosslinked by heating to a temperature above a first temperature threshold. This makes it possible to form the silicone from the liquid silicone rubber.

[0036] During a first step of the manufacturing process of the device 10, the liquid silicone rubber is mixed with a swelling agent, intended to form the cells of the core 18. Thus, a mixture of liquid silicone rubber is obtained.

[0037] The blowing agent functions in a similar manner to a blowing agent used to create cells in a thermoplastic material, such as, for example, Hostatron (registered trademark). In particular, the blowing agent is chosen to decompose and / or react, in particular by generating reaction gases, when a temperature above a second temperature threshold is reached, this second threshold being, optionally, higher than the aforementioned first threshold. The blowing agent is advantageously chosen so that the reaction gases are not toxic. In addition, a reaction rate of the blowing agent is such that the decomposition and / or reaction of the blowing agent in the liquid silicone rubber takes place while the liquid silicone rubber is not yet completely crosslinked, so that the cells can form.However, the reaction rate of the blowing agent is sufficiently low that the reaction gases produced by the reaction and / or by the decomposition of the blowing agent do not escape entirely from the still uncrosslinked liquid silicone rubber, and remain at least partly trapped in the liquid silicone rubber to form the cells.

[0038] In a second step, the liquid silicone rubber mixture is injected into a mold. The mold is heated to a temperature above the first temperature threshold. The first temperature threshold corresponds to a crosslinking temperature of the liquid silicone rubber, i.e. the temperature from which the liquid silicone rubber forms chemical bonds and becomes silicone.

[0039] A third step includes crosslinking an outer layer of the liquid silicone rubber mixture. Indeed, upon contact with the walls of the mold, which are at a temperature above the first temperature threshold, the outer layer of the mixture reaches this temperature and crosslinks quickly. In this outer layer, a crosslinking speed of the liquid silicone rubber is greater than the reaction and / or decomposition speed of the blowing agent, so that the blowing agent does not have time to significantly react and / or decompose and form cells in the outer layer of the mixture. An outer part of a part, without cells, is then formed.

[0040] A fourth step includes a step of heating an inner layer of the mixture. By heat transfer, the temperature of the inner layer of the mixture gradually increases.

[0041] A fifth step includes a step of expanding the blowing agent. When the temperature of the inner layer of the mixture becomes higher than the second temperature threshold, the blowing agent reacts and / or decomposes, forming gases within the inner layer. These gases form bubbles in the mixture.

[0042] A sixth step includes a step of crosslinking the inner layer. The temperature of the inner layer continues to increase until it becomes higher than the first temperature threshold. The inner layer crosslinks, becomes silicone, and the cells are formed in the silicone. An inner part of a part is formed at the end of this step.

[0043] In practice, the fourth, fifth and sixth steps may occur substantially simultaneously, or overlap. For example, the crosslinking of the inner layer and the expansion of the blowing agent may occur over a period of time and thus overlap.

[0044] A seventh step includes demolding the part: when the interior part is fully formed, the part is removed from the mold.

[0045] An eighth step includes shaping the part. The part is shaped, for example by being cut, in order to form the device 10, in particular the body 12 and to expose the free face 21. The inner part forms the core 18 and the outer part forms the skin 17. The free face 21 is for example a section formed during a cut of the part. The shaping can be a mechanical cut, a laser cut or any other process suitable for cutting silicone.

[0046] Thanks to the molding, the body 12 and the extension 14 are formed in one piece, as well as the skin 17 and the core 18, while having different porosities.

[0047] In the first step, the liquid silicone rubber is optionally mixed with other additives than the blowing agent, for example antibacterial additives and / or colorants. Advantageously, the liquid silicone rubber is mixed with additives such as organic peroxides, which act as vulcanizing agents. In this case, the liquid silicone rubber is vulcanized rather than crosslinked, i.e., covalent bonds are established between the polymer chains. The resulting device 10 is made of silicone comprising one or more additives.

[0048] The embodiments and variants mentioned above can be combined with each other to generate new embodiments of the invention.

Claims

Claims

1. Device (10) for applying a liquid, comprising a body (12) made of silicone, the body (12) including both a skin (17) made of liquid-tight silicone and a core (18) made of silicone with a honeycomb structure adapted to absorb the liquid, the core (18) being integral with the skin (17) and being covered by the skin (17) except at a free face (21) of the core (18) adapted to deposit and spread the liquid.

2. Device (10) according to claim 1, in which the body (12) is cylindrical in shape along a central axis (X12).

3. Device (10) according to claim 2, in which the free face (21) is beveled relative to the central axis (X12).

4. A device (10) according to any one of claims 1 to 3, wherein the silicone comprises an additive.

5. A device (10) according to claim 4, wherein the additive is antibacterial.

6. Applicator (31), comprising the device (10) according to any one of claims 1 to 5 and a gripping support (35) on which the device (10) is fixed.

7. The applicator (31) of claim 6, wherein the body (12) includes an extension (14) that is inserted into the gripping support (35) to secure the device (10) to the gripping support (35).

8. Cosmetic assembly (30), comprising the applicator (31) according to any one of claims 6 or 7 and a reservoir (32), containing a cosmetic liquid, the device (10) being adapted to be inserted into the reservoir (32) to bring the free face (21) into contact with the cosmetic liquid.

9. A method of manufacturing a device (10) according to any one of claims 1 to 5, comprising: - a step of mixing a liquid silicone rubber with a blowing agent to form a liquid silicone rubber mixture; - a step of injecting the mixture into a mold heated to a temperature greater than or equal to a first temperature threshold; - a step of crosslinking an outer layer of the mixture, in order to form an outer part of a part; - a step of heating an inner layer of the mixture; - a step of expanding the blowing agent, when the blowing agent reaches a temperature above a second temperature threshold, then forming cells in the inner layer of the mixture; - a step of crosslinking the inner layer to form an inner part of the part; and - a step of shaping the part to form the device (10) and make the free face (21) visible, the outer part of the part forming the skin (17) and the inner part forming the core (18).

10. The method of claim 9, wherein the shaping step includes cutting the part to form the body (12), a cut section formed during the cutting defining the free face (21).

Images