WO2012084732A1

WO2012084732A1 - Applicator and/or separating member having a high density of elements protruding from a support

Info

Publication number: WO2012084732A1
Application number: PCT/EP2011/073112
Authority: WO
Inventors: Vincent De Laforcade; Olivier Voisin
Original assignee: L'oreal
Priority date: 2010-12-21
Filing date: 2011-12-16
Publication date: 2012-06-28
Also published as: FR2968907A1; FR2968907B1

Abstract

A member (1), in particular for applying and/or separating, comprising a support (2) and a plurality of elements (3) protruding from a surface (4) of this support, each element extending along a main axis of extension (X) and being connected by way of its base (6) to the support and having a free end (7) opposite this base, the elements being produced in one piece with the support, wherein at least some of the elements are arranged on the support such that the density of the free ends is greater than 3 free ends per mm2, and preferably greater than 4.

Description

Applicator and/or separating member having a high density of elements protruding from a support

The present invention relates to a member, in particular an applicator and/or separating member, having a high density of elements protruding from a support. The invention is most particularly used in the field of the application of a cosmetic product to keratin materials, and/or the separation of keratin fibres, such as the eyelashes, eyebrows or hair. The expression "keratin materials" describes together the skin, the lips, the eyelids, the cheeks, the nails and keratin fibres.

The expression "cosmetic product" is understood to mean a product as defined in Council Directive 93/35/EEC of 14 June 1993.

Known in the field of the application of mascara to the eyelashes are what are known as "twisted" brushes, which are formed by an assembly of strands arranged in a helical manner by the twisting of metal wires around a layer formed by these strands. In this technology, there is known by way of example the teaching in document FR-2607373. Numerous brushes for the application of mascara, said brushes being obtained by moulding plastic, are also known.

Known in the field of the application of product to the skin are applicator members having a support made, for example, of cellular foam covered with a flocked surface to render it soft. Known from the teaching of document FR2917276 is a method for moulding a brushing or combing member using a very particular mould. This mould is obtained in particular by the assembly of two half-shells around each element to be formed, and of a third component for closing off the cavities formed between the two half-shells so as to define the shape of the elements to be moulded therein. This document enables the manufacture of a member provided with elements that protrude in relation to their support such that the elements are approximately cylindrical. A generatrix of a cylinder that defines the envelope surface of an element forms an angle of less than 2° in any position in relation to a main axis of extension of this element. This method enables the manufacture of a support provided with elements having a diameter of less than 1 mm.

Although satisfactory, these elements did not make it possible to obtain, at low cost, applicator and separating members that have a high density of elements protruding from their support. These prior art devices also do not make it possible to obtain, at low cost, a high density of fine elements in order to provide the softness and flexibility that is necessary for a cosmetic treatment of keratin materials. The object of the invention is to at least partly solve the problem set by the solutions known from the prior art. To this end, the subject of the invention is a member, in particular for applying and/or separating, comprising a support and a plurality of elements protruding from a surface of this support, each element extending along a main axis of extension and being connected by way of its base to the support and having a free end opposite this base, the elements being produced in one piece with the support, characterized in that at least some of the elements are arranged on the support such that the density of the free ends is greater than 3 free ends per mm², and preferably greater than 4 per mm². In particular, in order to have such a density of protruding elements for at least some of the elements of the support, a distance between two free ends of two adjacent elements within this part may be less than 1 mm. Preferably, this distance may be less than 0.5 mm and more preferably less than 0.3 mm. Advantageously, at least some of the elements may be configured such that they have a length measured along the main axis of extension of greater than 1 mm, and preferably greater than 5 mm, in particular greater than 8 mm, or even 10 mm. For example, at least some of the elements may be configured such that they have an approximately cylindrical portion such that the generatrix of the cylinder forms an angle of less than 2° in any position in relation to the main axis of extension. Thus, these particular elements may be non-conical. For example, at least some of the elements may be configured such that they have a cross section that has a diameter of less than 0.5 mm, and preferably less than 0.3 mm. Thus, the elements may have a certain flexibility on account of their fineness. The diameter may be greater than 0.1 mm.

Likewise, or alternatively, at least some of the elements may be configured such that a distance between two adjacent elements is less than 0.5 mm, and preferably less than 0.3 mm. Thus, these particular elements provide optimal product loading and progressive releasing of the product onto the keratin materials. This distance may be greater than 0.2 mm.

At least some of the elements may be configured such that they do not have a joint face parallel to their axis of extension. At least some of the elements may be disposed in an apparently random manner on the support. Specifically, inasmuch as the elements are obtained by moulding, this technique is not random, but highly reproducible. The appearance of a random arrangement makes it possible to give a "natural" character to these particular elements. Alternatively, an arrangement in rows may also be produced, but the advantage of the invention is that it provides a high density which at the same time is random, thereby making it possible to reproduce at low cost the density of the tufts of bristles or layers of bristles on the brushes and combs obtained by assembly on a support. Advantageously, the elements and the support may be produced by injection-moulding, for example from a thermoplastic elastomeric material, for example styrene-ethylene-butadiene-styrene (SEBS) or a polyester elastomer such as Hytrel^®. Thus, the elements have a very desirable flexibility for the application of cosmetic product to keratin materials, and in particular the skin. More generally, the member could be manufactured from elastomer material, or thermoplastic, or any material that can be moulded.

Preferably, in order to mould the member according to the invention, a polymer material will be chosen having stretching properties, to standard IS0527, of between 5% and 800%, and/or a flexural modulus, to standard IS0178, at 23°C, of between 50 MPa and 2000 MPa, and/or tensile strength, to standard IS0527, of between 10 and 3000 MPa, and/or a hardness, to standard IS0868, of between 10 Shore A and 85 Shore D, and/or a melt flow index, to standard IS01 133, of between 2 and 70 g/10 minutes at 190°C/2.16 K.

For example, the applicator and/or separating member may comprise a gripping region at the end of which the support is fixed. In this case, the complementary part, for example the gripping region, could be obtained either by bi-injection moulding, or by overmoulding, or by being joined to the support by any desired joining method.

The invention will be understood better from reading the following description and with reference to the accompanying figures. These are only presented by way of non-limiting indication of the invention. In the figures:

- Figure 1 shows a top view of one embodiment of an applicator member according to the invention;

- Figure 2 shows a top view of a particular implantation of elements protruding from a surface of an applicator member according to the invention;

- Figure 3 shows an enlarged view of a region of a number of mm² of a surface of the support from which the elements of an applicator member according to the invention protrude;

- Figure 4 shows a profile view of two elements of an applicator member according to the invention.

Figure 1 shows a comb 1 , used for example for applying a hair dye product to the hair. This comb 1 is an applicator member within the meaning of the invention. Other members may be produced according to the invention, for example brushes for styling the hair, brushes for applying mascara to the eyelashes, combs for applying product to the eyelashes, blusher-type brushes for spreading powder on the skin, cheeks or eyelids. The member may likewise or alternatively be configured to separate the eyelashes when they are already covered with mascara, or in order to arrange them before making them up. According to the invention, the member may also be used to scrape a powder sifter, or else be in the form of a wiper. In the case of the wiper, the free ends of the elements converge radially towards a centre of an approximately tubular support. In Figure 1 , the member 1 comprises a support 2 and a plurality of elements

3 protruding from a surface 4 of the support. The support 2 is defined at the end of a handle 5 that serves to make it easier to grip the member. The handle 5 has a main axis of extension X, which corresponds approximately to the main axis of extension of the member 1 . The handle 5 comprises a part that tapers along the axis X, then flares and is formed integrally with the support 2. In this example, the handle 5 and the support 2 are produced in one piece.

The plurality of elements 3 comprise at least two elements, preferably at least 50 elements protruding from the support. The surface 4 is defined here in a plane approximately perpendicular to the axis X. Also, in this example, the elements all protrude respectively along main axes of extension that are parallel to one another and also parallel to the axis X. Within the invention, not all of the bristles are necessarily parallel to one another, nor are they necessarily parallel to the axis X.

At least some of this plurality of elements are formed integrally with the support 2. In this example, the support and the plurality of elements are produced in one piece. In particular, all of the elements protruding from the surface 4 are produced in one piece with the support. Alternatively, it is conceivable for the member to comprise other types of protruding elements which are not formed integrally with the support.

The expression "form integrally" is understood to mean production from thermoplastics that are able to be overmoulded one on the other. This definition covers the case in which the assembly is moulded from one and the same thermoplastic.

In the example, all of the elements have the same length L1 along the axis X. The length L1 is 10 mm here. In comparison, the length L2 defined between the end of the handle, opposite the surface 4, and this surface 4 is of the order of a number of centimetres, for example at least 8 cm.

Each element comprises a base 6, by way of which it is secured to the surface 4, and a free end 7. The free end 7 is axially opposite the base 6.

Figure 2 is a view, perpendicular to that in Figure 1 , of the surface 4 and of the elements protruding therefrom. The surface 4 has a thickness e. For example, the thickness e is between 5 and 15 mm. In this example, the surface has an approximately parallelepipedal shape, such that the length L3 is much greater than the thickness e. For example, the length L3 is 3 times greater than the thickness e. The length L3 is for example between 10 and 45 mm.

In the example in Figure 2, the elements 3 are not implanted in regular rows. For example, elements which are respectively adjacent in pairs have bases which are not aligned along a straight line. Specifically, inasmuch as the elements are obtained by being moulded with the support by means of a very particular mould, this disposition can be obtained. The mould that is particularly useful for producing a member according to the invention comprises at least one block in which there are formed cavities respectively intended to form the elements. These cavities are for example obtained by electrical discharge machining of a block of steel intended to form the mould. The higher the quality of the steel, for example the higher its purity, the more the cavities can be formed with precision and miniaturization. The various cavities can be produced close to one another but do not have to be aligned. The cavities are open-ended and have a depth of the order of the length L1 of the element to be formed. Thus, the elements do not have a joint face along their axis of extension, and they thus have a very smooth surface over the entirety of their outer perimeter.

In order to close the mould, a shell is connected to this steel block in order to close off each of the through-cavities. After demoulding, this shell is spaced apart from the steel block in order to make cleaning easier, in particular at the cavities. At the junction between the steel block and the half-shell, it is possible for air to escape, thereby ensuring reproducible moulding of the elements. This junction contributes towards the formation of an annular joint face at the free end 7.

Thus the plurality of elements may have any desired distribution over the surface 4. However, although this distribution is as desired, it may be regular, although this is not a constraint imposed by the moulding technique for obtaining such a member 1 .

For example, in the case of an irregular distribution of the protruding elements, if consideration is given to a plurality of rectilinear lines P1 , P2, P3 and P4 which are parallel to one another and parallel to the surface 4, these lines will intersect a random number of protruding elements, and this random number will be different from one line to another. Alternatively, or as a complement, in the case of an irregular distribution, the distance between the adjacent elements intersected by one and the same line will have variable spacings along the line. In addition, it will be possible for these spacings not to be correlated with those of the adjacent line, or even those of the other lines. It is thus possible to obtain a member having a plurality of protruding elements that are nevertheless implanted in an "apparently random" manner in the surface 4.

As shown schematically in Figure 3, the advantage of the invention is that it provides a dense implantation of protruding elements on the support. The expression "dense implantation" is understood to mean implantation in which at least 3 free ends of elements are counted in at least one square of 1 mm² defined on the surface 4. The 3 free ends each have a cross section, more than half of which is in said square of 1 mm² in order to be counted in said mm². In the example in Figure 3, a square of 1 mm² can be seen, said square having 4 protruding free ends such as 4, all having a circular cross section of approximately the same diameter. In particular, if consideration is given to two lines P1 and P2, then the distance between the two elements intersected by P1 is greater than that observed for the intersections with P2. The base of the elements could have any desired cross-sectional form, for example a fillet or bevel, but at least one element will have neither a bevel nor a fillet, its base forming a right angle between the outer perimeter of the element and the surface 4. For example, all the elements comprise a base having a circular cross section and an identical diameter. Alternatively, it is conceivable to produce elements each having different forms and in particular different cross sections. Alternatively, the elements could have a plurality of lengths. The bristles are cylindrical. They have virtually no taper, by which it is understood that their outer perimeter is defined by a generatrix Z which, whatever its position around the base 6, intersects the axis of extension Y of said element so as to form an angle of less than 2°. In this case, the maximum diameter d1 of the cross section of the element is more or less always constant. In the example, d1 is equal to 0.3 mm. In the case in which the free end is slightly rounded and not perfectly flat, this maximum diameter is considered to remain constant over 95% of the height of the element along its axis Y.

The expression "distance between two adjacent elements" is understood to mean the shortest distance that can be defined between these two elements. It is thus the distance d2 which can be measured at the base 6 of said two elements, between their respective outer perimeters. In the example shown, d2 is equal to 0.3 mm. In the entire description, the expression "comprising a" should be understood as meaning "comprising at least one", unless specified to the contrary.

In the entire description, the expression "at least some of the elements" should be considered to include the expression "all of the elements", unless specified to the contrary.

Claims

1 - Member (1 ), in particular for applying and/or separating, comprising a support (2) and a plurality of elements (3) protruding from a surface (4) of this support, each element extending along a main axis of extension (X) and being connected by way of its base (6) to the support and having a free end (7) opposite this base, the elements being produced in one piece with the support, characterized in that at least some of the elements are arranged on the support such that the density of the free ends is greater than 3 free ends per mm², and preferably greater than 4.

2 - Member according to Claim 1 , characterized in that at least some of the elements are disposed in an apparently random manner on the support.

3 - Member according to Claim 1 or 2, characterized in that a distance (d2) between two free ends of two adjacent elements is less than 1 mm.

4 - Member according to any one of the preceding claims, characterized in that a distance (d2) between two free ends of two adjacent elements is less than 0.5 mm, and preferably less than 0.3 mm.

5 - Member according to any one of the preceding claims, characterized in that at least some of the elements are configured such that they have a length (L1 ) measured along their main axis of extension (Y) of greater than 1 mm, and preferably greater than 5 mm, in particular greater than 10 mm.

6 - Member according to any one of the preceding claims, characterized in that at least some of the elements are configured such that they have an approximately cylindrical portion such that the generatrix of the cylinder (Z) forms an angle of less than 2° in any position in relation to the main axis of extension.

7 - Member according to any one of the preceding claims, characterized in that at least some of the elements are configured such that they have a cross section that has a maximum diameter (d1 ) of less than 0.5 mm, and preferably less than 0.3 mm. 8 - Member according to any one of the preceding claims, characterized in that at least some of the elements are configured such that they do not have a joint face parallel to their axis of extension.

9 - Member according to any one of the preceding claims, characterized in that the elements and the support are produced from a thermoplastic elastomer material, in particular Hytrel ®. 10 - Member according to any one of the preceding claims, characterized in that it comprises a gripping region (5), at the end of which the support is fixed.