Curved-brush applicator for a cosmetic product

Abstract

The invention relates to an applicator for applying a cosmetic product, comprising an elongate core (2), the core comprising a brush (7) comprising protrusions forming bristles (10) protruding from the core (2), wherein the core (2) and the bristles (10) are formed as a single piece, the brush (7) has a curved shape, such that it has a concave region (11) and a convex region (12), the brush (7) has a first end (8) and a second end (9), and the bristles (10) are implanted in at least one row extending as a helix from the first end (8) towards the second end (9). The core (2) and the bristles (10) are formed by additive manufacturing, and the core (2) has a lattice structure.

Description

[0001] Cosmetic product applicator with curved brush

[0002] TECHNICAL FIELD OF THE INVENTION

[0003]

[0001] The present invention relates to an applicator for applying a cosmetic product. It applies in particular to mascara applicators, which are generally part of a mascara product. The invention is therefore described here with reference to such a mascara applicator, but it can of course be applied to other cosmetic products.

[0004]

[0002] A mascara product typically comprises a case, a mascara reservoir, and an applicator. The applicator includes a gripping portion and a brush. The mascara product may, in a known manner, include a cap or stopper designed to close the reservoir when mascara is not being applied, and which may form the gripping area of ​​the applicator.

[0005] STATE OF THE ART

[0006]

[0003] There are several types of conventional applicators: "brush" type applicators, injected applicators, and applicators manufactured by additive manufacturing. Regardless of the shape and manufacturing method of a known mascara applicator, the principle of applying mascara consists of loading the applicator with the product (mascara) contained in the reservoir, removing the applicator from the reservoir with the product-laden protrusions, and applying it to the user's eyelashes or eyebrows. For the sake of simplicity, only eyelashes will be mentioned below, although this does not preclude the use of the product and applicator on the user's eyebrows.

[0007]

[0004] There are many different geometries of applicators for cosmetic products, particularly for mascara applicators. The general aim is to allow the applicator to be loaded with enough product for application to one eye, while ensuring a high-quality application to the user's eyelashes, in particular by ensuring quality combing of the eyelashes.

[0008]

[0005] Patent application EP0568400 discloses a spoolie-type mascara brush whose bristles have protrusions shaped like balls, mushroom heads, or nails. This increases the brush's capacity to be loaded with mascara. US9370234 has a similar teaching. Documents KR200486386 and KR1020180018103 describe mascara brushes with a curved body and bristles on the concave and convex sides of the body. The bristles on the concave side and those on the convex side give the applicator different properties in terms of product loading and the ability to comb and separate the eyelashes.

[0009]

[0006] However, the design of mascara applicators can still be improved. This applies not only to their makeup performance but also to their ease of use, particularly with regard to the application technique. The present invention thus aims to provide a cosmetic product applicator, particularly for mascara, that combines a natural application technique for the user with a significant volume and curl effect for the eyelashes (or other hairs).

[0010] DESCRIPTION OF THE INVENTION

[0011] The objective stated above is achieved by means of an applicator for applying a cosmetic product, comprising an elongated core. The core includes a brush with protrusions forming bristles that project from the core. The core and the bristles (or protrusions) are formed as a single piece, and the brush has a curved shape, such that it has a concave and a convex area. The brush has a first end and a second end, and the bristles are implanted in at least one row extending helically from the first end to the second end. The core and the bristles are formed by additive manufacturing. The core has a lattice structure.

[0012]

[0007] The applicant has thus designed a cosmetic product applicator, particularly suited for applying mascara, which combines several advantages. The curved shape of the applicator's core creates a concave zone which, by bringing the free ends of the bristles closer together in this zone, creates a large volume for loading the product between the applicator's core and the bristles. This zone is therefore responsible for the majority of the product loading. The convex zone, on the other hand, causes the free ends of the applicator's bristles to spread apart in this area. This increases the applicator's ability to separate the eyelashes during application. In addition to these advantages, the helical arrangement of the bristles, which is counterintuitive on a curved core, increases the applicator's combing ability. The helical arrangement of the bristles also allows for a smooth transition between the concave and convex zones during mascara application.Thus, the user finds it natural to move from the concave to the convex area, following the movement suggested by the row or rows of hairs implanted in a spiral. Combing time is increased, and since the transition between the concave and convex areas is achieved in a single movement, the lashes are coated with mascara and combed in one continuous application.

[0013]

[0008] Various additive manufacturing processes can be used to form the applicator. In particular, a powder bed fusion process can be used. Preferably, a stereolithography or photopolymerization process can be used.

[0009] A lattice structure refers to any structure in which an intersecting or even interwoven reinforcement forms open meshes. Such a structure can exhibit greater flexibility, in some or all directions, compared to an equivalent solid structure made of the same material. It can also promote the retention and release of the cosmetic product. Such a lattice structure can also increase the volume of cosmetic product that the applicator can hold. It also reduces the amount of material used to construct the applicator.

[0014]

[0010] Thanks to the applicator's design, its bristles make more frequent contact with the eyelashes during application compared to known cosmetic applicator designs. The applicator's design also promotes a variety of bristle positions after the applicator passes through a wiper. The applicator's bristles form a geometric envelope that provides ample space for retaining the cosmetic product. Ultimately, the applicator's design allows for makeup application, particularly of eyelashes, giving them more volume, and avoids the risk of creating clumps of cosmetic product during application.

[0015]

[0011] The core and protrusions are advantageously formed from a flexible material. For example, they can be formed from Hytrel (registered trademark), or from other thermoplastic elastomer materials similar in terms of mechanical properties, particularly flexibility. Generally, materials having similar mechanical properties, particularly flexibility, can be used successfully.

[0012] The row(s) of bristles can form between one-eighth and one turn around the core.

[0016]

[0013] The applicator may have from one to twenty rows of bristles.

[0017]

[0014] The number of hairs per unit area may be greater in the convex area than in the concave area.

[0018]

[0015] We can thus speak of a higher bristle density in the convex area. A higher bristle density tends to improve lash combing, while a lower bristle density tends to improve lash separation. Each area therefore has a distinct primary role, and mascara application to the lashes can be achieved through a process of lash separation and combing, following a movement naturally suggested by the shape of the applicator body and the helical arrangement of the brush bristles.

[0016] The core of the applicator may have a cross-section that gradually decreases from the first end to the second end of the brush.

[0019]

[0017] This gradually increases the flexibility of the applicator towards the free end of the brush.

[0018] Each bristle of the applicator can have a length measured along said bristle from the core of the applicator to a free end of said bristle, and the average length of the bristles is shorter in the concave area than in the convex area.

[0020]

[0019] The average length is obtained, in a conventional way, by dividing the sum of the lengths of each hair in an area by the number of hairs in that area.

[0021]

[0020] Each hair can have, for example, a length between 1 mm and 5 mm. For example, each hair can have a length between 1.5 mm and 4 mm, for example on the order of 2.5 mm.

[0022]

[0021] Each hair can have a circular cross-section and a diameter between 0.1 mm and 0.8 mm, for example between 0.2 mm and 0.6 mm.

[0023]

[0022] Each hair having a free end, each hair can have a constant cross-section or an evolving cross-section which decreases from the nucleus towards the free end of the hair.

[0024]

[0023] Each hair may have a protrusion at its free end, in which a cross-section of the protrusion is greater than a cross-section of the hair at its free end. This protrusion may be ball-shaped. This protrusion may have other shapes, and may, for example, be egg-shaped, disc-shaped, nail-shaped, etc. It improves separation and combing and creates locally, at the tip of the protrusions, on the surface of the protrusion and just below this protrusion, at the interface with the rest of the protrusion, a local retention of cosmetic product which is applied progressively during application to the eyelashes or other hairs of the user.

[0025]

[0024] The core and protrusions of the applicator can be formed from a photopolymerized resin.

[0026]

[0025] Alternatively, the core and the hairs can be formed from a thermoplastic elastomer.

[0027]

[0026] The lattice structure of the core may include meshes, and these meshes may be sealed with an added material. This prevents or limits product retention in the meshes and can allow the mechanical properties of the brush to be adapted. It also protects, where applicable, the material constituting the applicator from degradation, particularly degradation of its mechanical properties, which could be caused by contact with the cosmetic product.

[0028] BRIEF DESCRIPTION OF THE FIGURES

[0029]

[0027] Other features and advantages of the invention will also become apparent from the following description.

[0030]

[0028] In the accompanying drawings, given by way of non-limiting examples: • Figure 1 presents a schematic three-dimensional view of a cosmetic product applicator according to an embodiment of the invention, the applicator being seen in profile;

[0031] • Figure 2 is a cross-sectional view of the applicator shown in Figure 1; and

[0032] • Figure 3 is a diagram of the protrusions that can be formed in certain embodiments of an applicator according to the present invention;

[0033] • Figure 4 is a schematic representation of one aspect of certain embodiments of the invention.

[0034] DETAILED DESCRIPTION OF THE INVENTION

[0035]

[0029] Figure 1 shows a schematic three-dimensional view of a cosmetic product applicator 1 according to an embodiment of the invention. The applicator 1 extends substantially along a longitudinal axis A. The applicator 1 comprises a core 2. The core 2 has a lower end 3 and an upper end 4. The lower end 3 and upper end 4 are substantially aligned along the longitudinal axis A.

[0036]

[0030] The core 2 has a base 5 that extends substantially longitudinally. The base 5 extends from the lower end 3 of the core 2 to a certain longitudinal level of the applicator. The base 5 can be used by the user to grip the applicator 1. Alternatively, and depending on its size and shape, the base 5 can be engaged with an applicator gripping element (not shown). In the example shown here, elements 6 projecting transversely from the base 5 ensure a good connection with a gripping element. The base may have a circular cross-section. In this case, the longitudinal axis A is the principal axis of the base 5.

[0037]

[0031] The applicator 1 also includes a brush 7 located between the upper end 4 of the core 2 and its base 5. In other words, the brush 7 extends from a first end 8 at the end of the base 5 to a second end 9 corresponding to the upper end 4 of the core 2. The brush 7 constitutes the active part of the applicator, enabling the application of a cosmetic product such as mascara. To this end, the brush 7 has protrusions that form the bristles 10 of the brush.

[0038]

[0032] An example of a bristle geometry that can be used in an applicator according to embodiments of the present invention is illustrated in Figure 3, which will be described in more detail below. Throughout this document, the terms "protrusion" and "bristle" 10 will therefore be used synonymously.

[0039]

[0033] In the example shown, the cross-sectional area of ​​the brush decreases between its first end 8 and its second end 9. In particular, this reduction in surface area can be between 20% and 50%. For example, in the example shown, the core 2 has a circular cross-section and the diameter of the core 2 at the first end 8 is 3.2 mm, while the diameter of the core 2 at the second end 9 is 1.8 mm. The decrease in the cross-sectional area of ​​the core from the base 5 to the second end 9 of the brush gives the applicator greater flexibility towards its free end.

[0040]

[0034] In an applicator according to the present invention, the brush 7 has a generally curved shape. This brush 7 therefore has a concave area 11 and a convex area 12. Furthermore, the bristles 10 are arranged in one or more rows. In the example shown here, the bristles 10 are arranged in twelve rows. The rows extend helix-wise from the first end 8 to the second end 9 of the brush 7.

[0041]

[0035] Between the first end 8 and the second end 9 of the brush 7 of the applicator 1, each row of bristles forms one-eighth to one full turn around the core 2. For example, each row of bristles forms a quarter turn around the core 2. In another example, each row of bristles forms a half turn around the core 2. The helical arrangement of the bristle rows improves the combing ability of the applicator 1 and follows the user's movement when applying mascara or another cosmetic product. In particular, it becomes natural for the user to move from the concave area 11 to the convex area 12 during the application movement while maintaining contact between the applicator and the eyelashes.

[0042]

[0036] Figure 2 is a cross-sectional view of the applicator 1 along the CC plane shown in Figure 1. Figure 2 shows in particular that the applicator has more bristles in the convex area 12 than in the concave area 11. More precisely, the number of bristles 10 per unit area (for example, the average number of bristles per cm²) 2The density of hairs is greater in the convex zone 12 than in the concave zone 11. This is explained by the primary role of each zone. The main objective of the concave zone 11 is to maximize product retention and facilitate lash separation. The main objective of the convex zone 12 is to ensure optimal lash combing. Therefore, in the concave zone 11, the goal is to create large volumes to retain the cosmetic product between the lashes. In the convex zone 12, the higher density of hairs allows for efficient lash combing. Furthermore, as can be seen in Figure 2, the distribution of hairs is virtually homogeneous in each of the convex and concave zones, respectively.

[0043]

[0037] The shape of the bristles of the applicator 10 is also optimized to improve the performance of the applicator 1 in terms of cosmetic product retention and combing, and more generally, the effectiveness of the applicator 1 during the application of the cosmetic product. An example of bristle geometry that can be used within the framework of the present invention is illustrated in Figure 3. According to various embodiments, each bristle 10 may have, over all or part of its length, a cross-section that is constant or that decreases from the core 2 of the applicator towards the free end of said bristle. Each bristle may thus have a generally cylindrical shape, or generally conical or frustoconical, or any other suitable shape.In the example shown in Figure 3, the hair 10 has a first part 13 with a constant circular cross-section, then a second part 14 with a cross-section that decreases regularly towards the free end of the hair.

[0044]

[0038] In any event, whether the cross-section of the hair is constant or changes along its length 10, each hair can advantageously have a protrusion 15 at its free end. The largest cross-section of the protrusion 15 is greater than the cross-section of said hair at its free end 16, just before said protrusion 15. The protrusion 15 can have different shapes. In the example shown here, it is ball-shaped. It can be, among other things, egg-shaped, disc-shaped, nail-head-shaped, or mushroom-shaped. At the protrusion, the hair thus transitions from a thin section, i.e., one with a small cross-section, to a significantly larger cross-section. This creates a recessed area, a concavity, allowing the cosmetic product to be retained in this area, under the protrusion.Such a protrusion 15 thus offers a larger surface area for product retention and also creates a product retention effect on the hair just below this protrusion 15. This protrusion 15 has also been found to improve eyelash combing. The protrusion 15 also softens the tip of the hair to prevent an unpleasant sensation on the eyelid. As an example only, assuming that the hair 10 has a circular cross-section, the dimensions of the hair 10 can be as follows. The hair can have a length L between 1 mm and 5 mm, preferably between 1.5 mm and 4 mm, for example, on the order of 2.5 mm. The diameter D1 at the first part 13 can be on the order of 0.5 mm. The diameter D2 at the free end 16 can be on the order of 0.2 mm. The diameter of the protrusion D3, which is ball-shaped here, can be on the order of 0.3 mm.The expression "in the order of" is understood as the value indicated plus or minus 30%.

[0045]

[0039] It should also be noted that in order to ensure the functions assigned to the concave and convex parts of the applicator, respectively, the average hair length is advantageously shorter in the concave part 12 and longer in the convex part 11. The average hair length in an area is defined as the sum of the length of each of the hairs in said area divided by the number of hairs.

[0046]

[0040] Furthermore, the diameter, or more generally the cross-sectional area, of the bristles can be larger in the concave area than in the convex area. As mentioned above, the shape of the core 2 can be adapted to give it flexibility. Moreover, the composition of this core 2 can itself be adapted to increase this flexibility.

[0041] Figure 4 is a schematic view of an applicator according to an embodiment of the invention. In Figure 4, the protrusions (bristles) of the applicator 1 have been omitted to better illustrate the appearance described with reference to Figure 4. Thus, the core 2 of the applicator shown here has a lattice structure 17, clearly visible in the detail view of Figure 4. The protrusions or bristles of the applicator, although not shown, may have a similar lattice structure.

[0047]

[0042] By lattice structure, it is understood that a framework 18 is formed by the material constituting the applicator, said framework forming meshes 19, or even, within the thickness of the applicator, pores. Such a lattice structure of the core 2 can be obtained by various additive manufacturing processes, in particular by stereolithography. A photosensitive resin, in particular a photopolymer resin, for example a photosensitive polyurethane resin, can be used to form the core 2.

[0048]

[0043] Other additive manufacturing techniques, such as powder bed fusion, can be used. Additive manufacturing can create thin frameworks of material that interlock and bond to form the desired structure.

[0049]

[0044] However, when it is desired to prevent the cosmetic product from penetrating the core 2, a material can be attached to the core and, more generally, to the applicator. The attached material then seals the meshes formed by the lattice structure of the core, and can, if necessary, fill the core structure.

[0050]

[0045] Even if the core does not have a lattice structure 17, an additive manufacturing process can be used to produce a complex shape of applicator and protrusions that resemble fine hairs.

[0051]

[0046] The present invention therefore proposes an applicator for cosmetic products, the performance of which is improved. This improvement is due to the generally curved shape of the applicator brush and a particular helical arrangement of the bristle rows. Furthermore, the bristle distribution and geometry are improved to maximize product retention and the applicator's combing capacity.

[0047] In addition to application performance, the helical arrangement of the bristle rows on the applicator has a positive effect on applicator handling. The core structure of the applicator is also improved in certain embodiments. Such an applicator can be obtained, in particular, using various additive manufacturing techniques.

[0052]

[0048] Nomenclature of reference symbols:

[0053] • 1. Applicator

[0054] • 2. Core

[0055] • 3. Lower end

[0056] • 4. Upper end • 5. Base

[0057] • 6. Elements (projecting transversely from the base)

[0058] • 7. Brush

[0059] • 8. First end of the brush * 9. Second end of the brush

[0060] • 10. Brush bristles

[0061] • 11. Concave zone

[0062] • 12. Convex area

[0063] • 13. First part of the hair • 14. Second part of the hair

[0064] • 15. Outgrowth

[0065] • 16. Free end of the hair

[0066] • 17. Lattice structure

[0067] • 18. Frame • 19. Mesh

Claims

1. Demands 1. Applicator for applying a cosmetic product, comprising an elongated core (2), the core comprising a brush (7) comprising protrusions forming bristles (10) projecting from the core (2), in which the core (2) and the bristles (10) are formed as a single piece, the core (2) has a curved shape, such that the brush (7) has a concave area (11) and a convex area (12), the brush (7) has a first end (8) and a second end (9), and the bristles (10) are implanted in at least one row extending helically from the first end (8) to the second end (9), the core (2) and the bristles (10) being formed by additive manufacturing, characterized in that the core (2) has a lattice structure (17).

2. Applicator according to claim 1, wherein the row or rows of bristles (10) form between one-eighth of a turn and one turn around the core (2).

3. Applicator according to claim 1 or claim 2, wherein it comprises from one to twenty rows of bristles (10).

4. Applicator according to any one of the preceding claims, wherein the number of bristles (10) per unit area is greater in the convex area (12) than in the concave area (11).

5. Applicator according to any one of the preceding claims in which the core (2) has a cross-section gradually decreasing from the first end (8) to the second end (9) of the brush (7).

6. Applicator according to any one of the preceding claims, wherein each hair (10) has a length measured along said hair from the core (2) of the applicator to a free end (16) of said hair, and the average length of the hairs (10) is shorter in the concave area (11) than in the convex area (12).

7. Applicator according to claim 6, wherein each hair (10) has a length between 1 mm and 5 mm, for example between 1.5 mm and 4 mm.

8. Applicator according to claim 7, wherein each bristle (10) has a circular cross-section and a diameter between 0.1 mm and 0.8 mm, for example between 0.2 mm and 0.6 mm.

9. Applicator according to any one of the preceding claims, wherein each hair (10) has a free end (16), and each hair (10) has a constant cross-section or an evolving cross-section which decreases from the core (2) to the free end (16) of the hair.

10. Applicator according to claim 9, wherein each hair (10) has a protrusion (15) at its free end (16), and wherein a cross-section of the protrusion (15) is greater than a cross-section of the hair (10) at its free end (16).

11. Applicator according to claim 10, wherein the protrusion (15) is ball-shaped.

12. Applicator according to any one of the preceding claims, wherein the core (2) and the bristles (10) of the applicator are formed of a photopolymerized resin.

13. Applicator according to any one of the preceding claims, wherein the core (2) and the bristles (10) are formed of a thermoplastic elastomer.

14. Applicator of any one of the preceding claims, wherein the lattice structure (17) of the core (2) comprises meshes (19), said meshes being closed by an added material.

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