The present invention relates to brushes for applying a cosmetic product to the eyelashes or eyebrows, notably a makeup or care product, for example mascara, and to packaging and application devices comprising such brushes.

Prior art and objectives of the invention

A very large number of applicators, in which the brush comprises a core formed by two arms of a metal wire that are twisted together and grip bristles, are known. Since the bristles used are generally the same length, once the arms are twisted, the brush has an envelope surface in the form of a cylinder of revolution. Such a cylinder of revolution shape has limited effectiveness in terms of loading the eyelashes with product and of lash separation.

Efforts have thus been made to give the envelope surface more complex shapes so as to form on the brush, after wiping, zones that are more heavily laden with product, making it possible to properly load the eyelashes, and zones that are less heavily laden or are laden little, these being usable to separate the eyelashes. Finding the shape that results in the optimum makeup result requires numerous tests, since many factors come into play.

In addition, it is economically advantageous for the brush to be able to be manufactured quickly and easily.

Brushes with a curved core and/or with machined notches or facets have been proposed.

FR 2 821 536 discloses a brush with a curved core having a cross section that varies along at least a portion of the length of the brush in a non-homothetic manner.

FR 2 836 800 discloses a brush comprising at least one notch, a cross section of the brush in a plane intersecting the notch not being circular. The notch makes it possible to store product when the brush is withdrawn from the container containing the product.

US 2009/0199862 discloses a curved brush having an envelope surface with facets.

FR 2 916 328 relates to a brush for applying a product to the eyelashes and/or eyebrows having a twisted core, bristles maintained in twist of the core and a connecting element comprising two elongated portions that are circumferentially spaced and separated from each other by the bristles. WO 2016/174045 discloses a brush for applying a cosmetic product to the eyelashes or eyebrows, comprising a core and bristles, the free ends of the bristles defining an envelope surface, the envelope surface having two ribs delimited by notches formed by two longitudinally extending flanks, the two flanks of at least one notch comprising flat portions.

WO 2016/169863 relates to a brush for applying a product to the eyelashes and/or eyebrows, comprising a core with a rectilinear proximal portion and a rectilinear distal portion forming a non-zero angle with the proximal portion, and bristles.

FR 2 991 560 discloses an applicator for applying a product to the keratinic fibers, having a brush comprising a core and bristles retained in a portion of the core. The free ends of the bristles define an enveloppe surface of general flattened form according to a flatness plane. The envelope surface defines two opposed principal faces. Each principal face presents a longitudinal notch extending on a half of the length of the portion of the core carrying the bristles. An edge and the notches are not parallel to a longitudinal axis of the core.

FR 2 932 657 concerns a reservoir and application device comprising an applicator having a stem and a brush at the end of this stem, the brush presenting a largest transversal dimension between 9 and 14 mm, the brush being at least 30% wider than it is thick in cross-section, a reservoir containing the product to be applied having a wiper member defining a wiper orifice traversed by the brush when it is removed from the reservoir, the diameter of the wiper orifice being between 2,5 et 5,5 mm.

At last, WO 2015/079358 relates to a method for manufacturing a brush for applying a product to the eyelashes or eyebrows, the brush having a twisted core and bristles held in the core, wherein a brush blank is produced. The core of the brush is deformed after it has been twisted, so as to obtain a core with a non-rectilinear longitudinal axis and then, the bristles are cut so as to give the brush a defined shape.

There is a need to make it easier to apply makeup along the entire row of eyelashes, and notably at the corner of the eye.

There is also a need to improve brushes, notably to benefit from brushes that are capable of satisfactorily making up the eyelashes and eyebrows, by providing a sufficient load of product and satisfactory combing. Brush

The invention aims to meet all or some of these needs and therefore the subject thereof, according to a first of its aspects, is a brush for applying a product to the eyelashes and/or eyebrows, comprising:

- a core that extends along a curved longitudinal axis, in a plane of curvature,

- bristles that are held by the core in a portion of the core bearing the bristles, the bristles having free ends that define an envelope surface, the envelope surface having a convex portion and a concave portion, on the opposite side from the convex portion, on account of the curvature of the core,

- at least one furrow that extends longitudinally, in the concave part of the envelope surface (S), along at least a part of the length of the portion of the core bearing the bristles, said at least one furrow having a total length greater than or equal to 50%, better still at least 60%, or even at least 70%, of the length of the portion of the core bearing the bristles.

The convex portion advantageously does not have a furrow.

The lengths are measured after the core has been straightened so as to render it rectilinear, or on a blank of the brush before the core is curved.

By virtue of the invention, a loading zone can be created within the zone of the curved brush that is least accessible to the product, that is to say on the concave side in which the bristles are closer together on account of the curvature of the brush.

Specifically, when brushes are curved, the bristles are moved apart on the convex side and toward one another on the concave side in the hollow of the brush. The closer- together bristles leave less room for the product. By virtue of the invention, a space is created between the bristles in the region of the furrow, which is filled with the bristles when the core is curved. Thus, the furrow(s) formed in the brush make it possible to open up the concave side of the brush. They improve the properties of loading and curling the eyelashes on the concave side of the brush, rather than carrying out two makeup steps by loading the eyelashes or eyebrows with product with the domed convex side and then shaping and combing the eyelashes or eyebrows with the concave side. It is thus possible to carry out loading and combing with the same side, notably the concave side.

Within the meaning of the invention, the "convex portion" and "concave portion" are understood to be a "portion that is convex toward the outside" and "portion that is concave toward the outside", respectively, that is to say as seen by a viewer of the brush, when the latter is viewed in a direction perpendicular to the plane of curvature.

Said at least one furrow may be configured such that it is substantially not visible at least when the brush is viewed in a direction perpendicular to the plane of curvature of the core. In particular, less than 10% of the total area of the furrow may be visible in this direction.

The length of the portion of the core bearing the bristles may be between 15 mm and 45 mm, better still between 20 mm and 40 mm, for example between 25 mm and 35 mm. Said at least one furrow may extend, along the brush, along a total length of between 8 mm and 23 mm, notably between 11 mm and 21 mm, or even between 13 mm and 18 mm.

Said at least one furrow may have, at least before the core is curved, an angular extent, in a section plane transverse to the core, strictly less than 20°, notably less than or equal to 18°, preferably less than or equal to 15°.

The brush may comprise a single furrow.

The furrow may be centered on a median plane for the curvature of the core.

Said at least one furrow may be substantially rectilinear when viewed in a direction perpendicular to the plane of curvature.

In a variant, the brush may comprise at least two furrows, the distance between two adjacent furrows being between 1 mm and 10 mm. The furrows may be aligned with one another. In the case of a plurality of furrows, the lengths of the furrows are added together to determine the total length of said at least one furrow.

Advantageously, none of the furrows is visible in the direction perpendicular to the plane of curvature. In a variant, less than 10% of the total area of each furrow is visible.

Said at least one furrow may have a substantially V-shaped cross section, at least before the core is curved. In a variant, the cross section of said at least one furrow may substantially form a U, at least before the core is curved.

At least a part of the bottom of said at least one furrow may be coincident with the core.

The "bottom of the furrow" is understood to be the part of the furrow that is closest to the core. The bottom may be formed by a line or a point. Away from the bottom, the furrow comprises sides that extend from the bottom of the furrow. The whole of the area formed by the sides and the bottom forms the total area of the furrow. It is possible for the bottom of the furrow not to be visible when the brush is viewed in a direction perpendicular to the plane of curvature of the core.

The bottom of said at least one furrow may be at a minimum distance from the core of between 0 and 5 mm, preferably between 1 mm and 4 mm. The bottom of said at least one furrow may be curved or flat. It advantageously has a curvature substantially similar to that of the core, thus being parallel to the curved longitudinal axis of the latter. In a variant, provision may be made for the curvature of the bottom of the furrow to be different than the curvature of the core.

Said at least one furrow has, for example, a maximum depth of between 1 mm and 5 mm. The maximum width of said at least one furrow, before the core is curved, may be less than 6 mm, notably between 1 mm and 5 mm.

Said at least one furrow may exhibit symmetry with respect to the plane of curvature and/or with respect to the median plane perpendicular to the plane of curvature. When there are at least two furrows, these may be substantially identical to one another and exhibit symmetry with respect to the plane of curvature and/or with respect to a median plane perpendicular to the plane of curvature.

Said at least one furrow may be deeper than it is wide. The width of the furrow may be constant or variable. Similarly, the depth of the furrow may be constant or variable.

The core may be free of any sharp bends, that is to say its curvature is distributed along its length.

The radius of curvature of the longitudinal axis of the core may be between 20 mm and 60 mm, for example around 45 mm.

The core may be twisted, that is to say formed by two arms of a wire that are twisted together and grip the bristles. Said at least one furrow differs from the helical groove created when the core is twisted.

One advantage of the invention is that more bristles can be put on the core. Specifically, with the core being curved after one or more furrows have been created, this/these furrows create a space for accommodating more bristles. The furrow(s) may create a clearance in the curvature.

When the core is twisted, the number of bristles per turn may thus be greater than 5, better still between 10 and 30 bristles per turn, for example around 15 bristles per turn of the core. The "number of bristles per turn" denotes the number of bristle ends counted for a rotation of 180° about the longitudinal axis of the core.

The core may be twisted to the left or to the right. The bristles may extend from the core in two helical layers. The number of turns corresponds to the total number of revolutions of the two layers about the core. The bristles may be made of a natural or synthetic material, for example chosen from PP, PA, PET, PS, PE or PVC. The bristles may have a magnetic filler or one for improving sliding, for example graphite, PTFE or molybdenum disulfide.

Packaging and application device

The invention also relates to a packaging and application device comprising: a container containing a product to be applied,

a brush as defined above.

The container may be provided with a wiping member for removing the excess product present on the stem and on the brush. This wiping member comprises, for example, a lip made of an elastomer material, defining a wiping orifice which preferably has a circular cross section, the diameter of which corresponds substantially to that of the stem.

Manufacturing method

According to another of its aspects, the invention relates to a method for manufacturing a brush as defined above, comprising the following steps of:

i. taking a brush blank, comprising a core and bristles, that extends along a rectilinear longitudinal axis (Y),

ii. forming at least one furrow that extends longitudinally, along at least a part of the length of the portion of the core bearing the bristles, said at least one furrow having a total length greater than or equal to 50%, better still at least 60%, or even at least 70%, of the length of the portion of the core bearing the bristles,

iii. curving the core in a plane of curvature, the bristles having free ends that define an envelope surface (S), the envelope surface (S) having a concave portion and a convex portion, on the opposite side from the concave portion, on account of the curvature of the core, the curvature of the core being realized such that said at least one furrow extends at least partially in the plane of curvature in the concave part of the envelope surface of the brush. Advantageously, said at least one furrow is formed such that less than 10% of its total area is visible at least when the brush is viewed in a direction perpendicular to the plane of curvature of the core.

In one particular embodiment, said at least one furrow is formed at least partially as far as the core.

Said at least one furrow may be produced by melting bristles, for example by exposing them to laser radiation, or by bringing them into contact with a hot former, the material of the bristles then being chosen so as to allow the bristles to melt in contact therewith. Said at least one furrow may also be produced by clipping the brush before changing the shape of the core by curving.

Said at least one furrow may be partially eliminated when the core is curved.

Makeup method

A further subject of the invention is a method for making up the eyelashes or eyebrows, wherein the concave part of a brush according to the invention is used to load and separate the eyelashes. In particular, the entire makeup application process may be carried out using the concave part of the brush.

Figures

The invention may be understood better from reading the following detailed description of nonlimiting illustrative embodiments thereof and from studying the appended drawing, in which:

- Figure 1 shows an example of a packaging and application device according to the invention, in schematic and partial longitudinal section,

- Figure 2 is a side view of an example of a brush according to the invention,

- Figure 3 is a view of the brush in figure 2 before the core is curved, - Figure 4 is a schematic view along the arrow IV,

- Figures 5 to 7 are analogous views to figure 4 along the arrows V, VI and VII, respectively,

- Figure 8 is a view similar to figure 2 of another example of a brush according to the invention,

- Figure 9 is a view of the brush in figure 8 after the core has been straightened,

- Figure 10 is a view in schematic and partial longitudinal section of another example of a brush according to the invention, - Figure 11 is a schematic side view of an example of a brush according to the invention before the core is curved,

- Figure 12 is a schematic view along the arrow XII, and

- Figure 13 is a side view of another example of a brush according to the invention before the core is curved.

In the rest of the description, identical elements or elements having identical functions bear the same reference signs. Their description is not repeated for each of the figures, only the main differences between the embodiments being mentioned.

The packaging and application device 1 shown in figure 1 comprises a container 2 containing a product C to be applied to the eyelashes or eyebrows and an applicator 3 which may be fixed removably to the container 2 in the example in question. The product C comprises, for example, one or more pigments, notably an iron oxide. It is, for example, a mascara.

The applicator 3 comprises a stem 5, of longitudinal axis Z, provided at a distal end 5 a with a brush 10 according to the invention and at the other end with a gripping member 11 , which also constitutes a cap for closing the container 2 in a sealed manner. As can be seen notably in figure 1, said container 2 has a body 13 provided at the top with a threaded neck 14 onto which the gripping member 11 can be screwed in order to close the container 2 in a sealed manner. In a variant, the applicator may be fixed to the container in some other way.

The neck 14 may accommodate, as illustrated, a wiping member 20 which is for example inserted into the neck 14. This wiping member 20 comprises a lip 26 that defines a wiping orifice having a diameter adapted to that of the stem 5.

The brush 10 may be fixed, in a conventional manner, in a seat provided at the distal end 5a of the stem 5, which is advantageously made of a thermoplastic material. The brush 10 comprises a twisted metal core 40 comprising a portion 43 bearing bristles 41. The core is fixed at a proximal end 40a in the corresponding seat of the stem 5, via a portion without bristles that may have a length of around 8 mm. The portion 43 of the core bearing the bristles has a free end 40b.

The core 40 is formed conventionally by two arms of a metal wire folded in a U- shape, the bristles 41 being held between the turns of the core 40 thus twisted. The diameter of the metal wire is for example between 0.1 and 1 mm. The diameter of the bristles is for example between 0.06 and 0.35 mm.

The core 40 of the brush 10 according to the invention is curved, extending along a curved longitudinal axis X. It is curved in a plane of curvature P which, in the example described, is a plane that contains the longitudinal axis X and corresponds to the plane of the drawing as regards figure 2. This plane of curvature P is a plane of symmetry for the brush in this example. The brush is curved along the entire length of the portion 43. The distal end 40b of the core is situated on the longitudinal axis X.

As illustrated in figure 2, the free ends of the bristles 41 define an envelope surface S of the brush 10. The envelope surface S has a portion 30 that is convex toward the outside and portion 31 that is concave toward the outside, on the opposite side from the convex portion 30, on account of the curvature of the core 40.

The bristles 41 extend over the portion 43 of the core that has a length L of the core of preferably between 25 mm and 35 mm, for example equal to 30 mm, measured after the core 40 has been straightened or on a blank of the brush before the core is curved, as is visible in figure 3.

The brush also comprises at least one furrow 45, indicated by dotted lines in figures 2 and 3, that extends longitudinally in the concave part of the envelope surface, along a length Li equal to at least 50% of the length L of the portion of the core bearing the bristles 41 , said lengths being measured as can be seen in figure 3. In this example, the furrow 45 is configured such that it is not visible, at least when the brush is viewed in a direction perpendicular to the plane of curvature P of the core, as in the example in figure 2.

In the example illustrated, the furrow 45 is centered on the median plane M for the curvature of the core 40. It does not extend along the entire length L of the portion 43 of the core bearing the bristles 41. In this case, Li<L. The depth a of the furrow 45 is variable at least in the end portions 45a and 45b of the furrow 45, in which the depth decreases. The bottom 46 of the furrow 45 is, for example, at a distance d equal to 3 mm from the core 40 in the central part of the furrow 45, which is the deepest part thereof.

By virtue of the invention, the densification brought about by the curvature of the core in the concave portion is not as great as in the absence of a furrow, such that the bristles located in the concave portion can occupy clearances formed by the furrow 45. In order to produce the brush 10, a brush blank that comprises a core 40 and bristles 41 and extends along a rectilinear longitudinal axis Y is taken, as can be seen in figure 3, and then at least one furrow 45 that extends longitudinally along at least a part of the length of the portion 43 of the core 40 bearing the bristles 41 is formed, advantageously by melting the bristles 41 with the aid of laser radiation, as can be seen in figure 3.

Figures 4 to 7 show cross sections through the blank in section planes transverse to the longitudinal axis Y of the core before it is curved.

In figure 4, the section plane is located in a portion of the core 40 in which there is no furrow 45. The bristles 41 occupy the entire circumference about the core 40.

In figure 5, the cross section shows the furrow 45 having, at this level, a depth ai and a maximum width ei, ai and ei being equal to 2 mm and 3 mm, respectively.

In the cross section visible in figure 6, the depth a ₂ is the maximum depth of the furrow 45, equal to about 3 mm in this example, located at a distance d ₂ of 2 mm from the core 40. Furthermore, the maximum width of the groove 45 is equal to ei, i.e. the width of the furrow 45 is constant along the entire length thereof, in this example. The furrow 45 covers an angular sector a less than or equal to 18°, preferably less than or equal to 15°.

Figure 7 illustrates a cross section close to the proximal end 40a of the core 40, which does not comprise the furrow 45, like the cross section in figure 4.

As can be seen notably in figures 2 and 4 to 7, in this example, the convex portion 30 does not have a furrow.

In the example illustrated, the plane of curvature P is a plane of symmetry for the furrow 45.

Once the blank with the furrow 45 has been produced, the core 40 is curved in the plane of curvature P, such that, in this example, the plane of curvature P forms a plane of symmetry for the furrow 45, and such that the latter is located in the concave portion 31 of the envelope surface S.

When viewed from the side, in a direction perpendicular to the plane of curvature P, the furrow 45 is substantially not visible.

When the core is curved, the clearance produced by the furrow 45 allows the bristles to extend further where, in the absence of a furrow 45, the density of bristles could prevent proper loading of the bristles. By virtue of the invention, the loading of the bristles in the concave portion of the brush is satisfactory. Also by virtue of the invention, the quantity of bristles per turn of the twisted core can be densified so that a furrow 45 in the concave portion of the core will make it possible to form a clearance.

In the example in figures 2 to 7, a single furrow 45 is formed.

Figures 8 and 9 show the possibility of producing a plurality of furrows 45, there being five thereof in the example illustrated. The number of furrows may be equal to two, three, four or more than five without departing from the scope of the invention. The total length∑L ₂ of the furrows 45, which is equal to the sum of the lengths L ₂ of each of the furrows 45, is greater than 50% of the length L of the portion 43 of the core 40 bearing the bristles 41. The lengths L and L ₂ are measured as illustrated in figure 9, after the core has been straightened.

The distance d ₃ between two adjacent furrows 45 is 1 mm in this example. This distance d ₃ between furrows may be the same or different depending on the adjacent furrows 45 in question. In the example illustrated, it is constant. The length L ₂ of the furrows 45 is identical for all the furrows 45 in this example, but it could be different without departing from the scope of the invention.

In the example illustrated in figures 2 to 7, it can be seen that the furrow 45 is V-shaped in cross section, as can be seen in figures 5 and 6.

When there are a plurality of furrows 45, these can extend in an aligned manner, as can be seen in figures 8 and 9. In this example, the furrows 45 shown are V-shaped, longitudinally, but this shape may be different, U-shaped or more elongate, without departing from the scope of the invention. In cross section, they may each be similar to the furrow 45 in figures 2 to 7, or not.

In figures 2 and 8, only some of the bristles 41 are shown, but, as can be seen in figures 3 to 9, these occupy the entire portion 43 of the core bearing the bristles.

In the examples in figures 2 to 7, for the one part, and 8 and 9, for the other part, the envelope surface S has a frustoconical shape close to the distal end 40b of the core.

In the example illustrated in figure 10, the brush 10 comprises a curved core 40 such that the distal end 40b of the brush is located on the axis Z of the stem. In the example in figures 1 1 and 12, it can be seen that the furrow 45, of which there is only one in this example, extends as far as the core 40 and has a constant depth along its entire length.

In the example in figure 13, the furrow 45 extends along the entire length L of the portion 43 of the core 40 bearing bristles 41. In this example Li=L. This furrow 45 likewise has a constant depth. It should be noted that, in this example, the length of the bristles 41 is constant substantially over the entire portion 43 of the core bearing the bristles.

The invention is not limited to the examples which have just been described, the characteristics of which can be combined with one another as parts of variants which are not illustrated. The envelope surface may have various overall shapes.