WO2018104340A1

WO2018104340A1 - Applicator for applying a cosmetic product, notably a foaming cosmetic product

Info

Publication number: WO2018104340A1
Application number: PCT/EP2017/081581
Authority: WO
Inventors: Soukaï DIOUF
Original assignee: L'oreal
Priority date: 2016-12-09
Filing date: 2017-12-05
Publication date: 2018-06-14

Abstract

The present invention relates to an applicator (1) for applying a cosmetic product, notably a foaming cosmetic product, in particular a cleansing or care product, comprising an elongate main body (10) made from an open-cell porous material that is elastically compressible in at least a substantially longitudinal direction of said elongate body, and having a lateral application surface (11) and two opposite end surfaces (12), said applicator being characterized in that at least one end surface of the main body comprises a stiffener that is intended for gripping and has a rigidity that is higher relative to the main body.

Description

Applicator for applying a cosmetic product, notably a foaming cosmetic product

The present invention relates to applicators for applying a cosmetic product, of the type of compressible porous applicators with open porosity, of the sponge or foam type.

The term "cosmetic product" denotes any composition as defined in EC Regulation No 1223/2009 of the European Parliament and Council of 30 November 2009 relating to cosmetic products.

The present applicator is particularly intended to be used with a foaming cosmetic product, for which the formation and obtaining of an abundant foam is desired during application.

Of course, when it relates to the cosmetic product, the term "foam" means a liquid foam and should be distinguished from the term "foam" used in relation to the applicator, which is thus a solid foam notably of the polyurethane foam type.

The foam of the cosmetic product results from the dispersion of a relatively large volume of gas (in particular air) in a relatively small volume of liquid. More specifically, it is a liquid foam comprising a number of gas bubbles (dispersed phase), notably air, separated by liquid films (continuous phase). The liquid contained in a foam flows between the bubbles under the effect of gravity and capillary forces. Surfactants present in the cosmetic product are adsorbed at the water/gas (air) interface during the introduction of air bubbles into the composition, and ensure the formation of liquid films and the maintenance of the structure of the foam.

A "foaming cosmetic" product is thus understood as meaning a cosmetic product that is able to form a foam when gas bubbles are injected.

To this end, the cosmetic product comprises at least one foaming agent.

A foaming agent is understood to be a surfactant compound having an HLB (Hydrophilic Lipophilic Balance) greater than or equal to 8, preferably greater than 10, or even greater than 13. The HLB characterizes the ratio of the hydrophilic portion to the lipophilic portion in the molecule. This notion of HLB is well known to a person skilled in the art. It is notably described in "The HLB system. A time-saving guide to Emulsifier Selection" (published by ICI Americas, 1984).

The cosmetic product may be a liquid, for example aqueous or oily, product. In a variant, it is a paste or a powder intended to be at least partially dissolved in a solvent, in particular an aqueous solvent, notably water. Within the meaning of the present application, the expression "liquid cosmetic product" will be used, without distinction, for a cosmetic product already in liquid form or a cosmetic product in solid form, notably a paste or a powder, which requires the addition of external water and is in a liquid form following dissolution.

Examples of such products are notably shower products, face cleansers, care products, microemulsions, micellar water, etc.

As indicated above, the production of a foam requires the injection of gas bubbles into the liquid cosmetic product.

When the cosmetic product is dispensed with the aid of an aerosol or pump type device, it is possible to form the foam directly from a diffuser or an associated nozzle for injecting the gas simultaneously with the dispensing of the product.

Alternatively, it is sometimes necessary to manually foam certain products, notably cleansing products which are packaged in a tube, bottle or pot.

This can be carried out with the aid of a compressible porous applicator with open porosity, of the foam sponge type.

The compressible nature of the applicator allows the user to alternately carry out compressing and releasing movements of the applicator which allow the injection of air into and dispersion of air in the liquid cosmetic product previously absorbed into the applicator.

More specifically, a quantity of foaming liquid cosmetic product is deposited on a surface of the porous applicator and then, by alternately carrying out repetitive compressing and releasing movements of the applicator, for example with the aid of their hand, the user allows the introduction of air bubbles into the cosmetic product, this introduction causing the formation of the desired foam.

There is a need to improve and make easier the use of such applicators and thus to make easier the formation of a better quality and/or more abundant foam.

There is also a need to benefit from an applicator that offers new opportunities in the fields of esthetics, hygiene and ergonomics.

To this end, the present application relates to an applicator for applying a cosmetic product, notably a foaming cosmetic product, in particular a cleansing or care product, comprising an elongate main body made from an open-cell porous material that is elastically compressible in at least a substantially longitudinal direction of said elongate body, and having a lateral application surface and two opposite end surfaces, said applicator being characterized in that at least one end surface of the main body comprises a stiffener that is intended for gripping and has a rigidity that is higher relative to the main body.

The stiffness is notably characterized through the modulus of elasticity of the material (see notably ASTM D3574 E), notably by the tensile properties (ISO 527/ISO 1926 depending on the nature of the material) and/or bending properties (ISO 178/ISO 1209 depending on the materials) of the material.

Preferably, both opposite end surfaces comprise a stiffener. Further preferably, the stiffener covers the entire end surface.

Thus, by providing an elastically compressible central main body that is situated between two stiffeners that are relatively rigid compared with the main body, a cosmetic applicator of the concertina type is obtained that is easy to grasp and can be successively compressed and released a large number of times in an ergonomic and comfortable manner, in order to expand and foam up the liquid cosmetic product absorbed into the applicator.

According to a preferred embodiment, the main body defines a substantially cylindrical overall envelope. Such a shape is particularly ergonomic and has a high level of comfort on application.

Advantageously, the lateral application surface extends over at least half the periphery of the main body, preferably over the entire main body.

In a complementary advantageous manner, the main body has at least one longitudinal groove. Such a groove can be used to deposit the desired quantity of cosmetic product without any risk of it running. More generally, such a groove forms a cavity for receiving the cosmetic product.

Preferably, the main body is produced from a foam, in particular a polyurethane foam. The porous material could have a porosity typically of between 60 and 90 PPI ("pores per inch").

According to a variant embodiment, the porous material can be flocked, notably on the lateral application surface (preferably the entire application surface).

Advantageously, the stiffener is impermeable to the cosmetic product. The term impermeable is understood as meaning greatly or even completely limiting the passage of liquid at said ends of the main body. This notably allows the user to keep their fingers clean of cosmetic product which would have diffused through the foam, in particular during a compressing movement. The stiffener may thus be solid (nonporous) or even porous with sufficiently fine porosity to significantly limit the propagation of the cosmetic product through said end stiffener. Thus, the time for the cosmetic product to pass through said end stiffener could be greater than the duration of application of the cosmetic product, and preferably one or more minutes, or even one or more hours.

According to a first embodiment, the stiffeners are in the form of plates attached to the end of the main body.

The end plates could be produced notably from a thermoplastic material of the polyethylene or polypropylene type.

The end plates could be attached and fixed by any means, notably by bonding or welding to the main body (notably by flaming a surface layer of the porous material allowing the adhesion of the stiffener).

According to a second embodiment, at least one stiffener, preferably both stiffeners, is/are an integral part of the main body.

Preferably, the stiffener is produced by permanent compression of a thickness of the main body (felting). The felting thickness extends from the end surface.

The felting of a foam denotes a thermoforming method in which a foam, in particular a polyurethane foam, is compressed permanently by placing a block of foam (obtained beforehand for example by cutting from a larger block) between two heated cavities of a mold and by compressing said block of foam until the deformation is permanent.

The felting treatment thus results from hot compression and allows the open-cell porous material to be shaped rapidly without its structure being damaged, in contrast to grinding, which can cause the material to be torn or shredded.

This felting treatment makes it possible to obtain a "crust" or skin of lower porosity on the face(s) treated. This skin is much stiffer than the initial foam and can thus constitute the stiffener.

This crust or skin may have a thickness of between 0.2 and 3 mm, better still between 0.3 and 2 mm, or even between 0.5 and 1 mm. The thickness of the felted skin will be adapted depending on the desired stiffness and/or impermeability.

The felting method used can be for example as described in the patent US 8 247

466, incorporated herein by reference. More particularly, as indicated in the document US 8 247 466, it is known that a low level of compression during the felting method does not allow a felted structure to be obtained through the entire thickness of the foam.

This method is known under the term variable felting. On account of the low level of compression of the foam in the heated mold and a short heating time, the foam is not felted through its entire thickness and only the upper and lower surfaces, in contact with the heated surfaces of the mold, are "felted". The internal structure of the foam is not substantially modified. The felted upper and lower surfaces thus form stiffening skins, produced directly, and incorporated into the central body.

The present invention also relates to a method for using an applicator according to the invention, characterized in that it comprises the steps of:

disposing a quantity of liquid cosmetic product, notably a foaming cosmetic product, in particular a cleansing or care product, on the lateral surface of the main body of the applicator,

grasping the applicator by its end stiffeners,

carrying out alternate compressing and releasing movements so as to foam up the liquid cosmetic product,

applying the cosmetic product foam by bringing the lateral application surface into contact with a body surface to be treated, notably a surface of the face.

Preferably, the applicator is grasped in one hand, notably between a thumb and at least one finger from an index finger and a middle finger.

Advantageously, during the application step, the applicator is grasped and compressed so as to have a part of its lateral application surface stretched and an opposite part of its application surface squeezed, compared with a rest configuration of the main body.

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 is a schematic perspective depiction of an applicator according to the invention,

- Figure 2 is a front view depiction of the applicator in figure 1 ,

- Figure 3 is a cross-sectional view on the line A-A of the applicator in figure - Figure 4 is a top view depiction of the applicator in figure 1.

Figure 1 shows a cosmetic product applicator 1 according to the present application.

The applicator 1 is intended to apply a foaming cosmetic product, in particular a cleansing or care cosmetic product.

The applicator 1 comprises an elongate body 10 made from an elastically compressible open-cell porous material.

More specifically, the body 10 is made from a polyurethane foam. If appropriate, other types of foam, notably injected, or porous materials can be envisioned.

It may for example be conceivable to use a polyamide (nylon) foam, a polyurethane (PU) foam, a polyacrylonitrile (PAN) foam, a polyethylene (PE) foam, an EVA foam, a PVC foam, a polyurethane foam impregnated with a thermoplastic elastomer, a cellular EPDM rubber, a cellular NeopreneTM rubber, a cellular nitrile rubber (NBR/PVC), a compact NeopreneTM rubber, a hard EPDM rubber, a solid SBR rubber, a compact nitrile rubber, a spongy rubber (EPDM, NeopreneTM, silicone), a polyether and/or a polyester.

The body 10 has a substantially cylindrical shape. The body 10 has a diameter of around 47 mm.

The body 10 has a length of between 60 and 80 mm, preferably around 70 mm. As will be seen below, such a length allows the applicator to be comfortable to grasp between the fingers of one hand (thumb and index/middle finger, notably) and allows a sufficiently large compressing/relaxing movement.

More generally, in order to maintain good compressibility of the body while having a sufficient lateral application surface, the ratio between the length of the applicator and its width will be greater than 1.4.

In a complementary manner, the body has a longitudinal groove 15. The groove

15 extends substantially over the entire height of the applicator 10.

The groove 15 may notably be produced by stamping in an initial block of porous material. The groove 15 has a cross section that is meniscus-shaped, notably concave, in particular substantially semicircular. The groove has a width of around 20 mm. The groove has a depth of around 3 mm.

The body 10 has a free lateral application surface 11 that extends around the entire periphery of the body 10 and two opposite end surfaces 12. The body 10 is elastically compressible in at least a longitudinal direction of the body 10.

In accordance with the present application, the end surfaces 12 each have a stiffener having a rigidity that is higher relative to the main body.

The end surfaces 12 each have a slightly convex overall shape.

The stiffeners are an integral part of the main body 10 and are obtained by variable felting of the initial block of foam, as explained above and in the document US 8 247 466.

To this end, the initial block of foam is introduced into a mold having an internal cavity with a height much less than the length of the block of foam.

In this case, for such an applicator 1 having a height of around 70 mm, the mold used has an internal cavity 23 mm high.

Preferably, the total height of introduced porous material is greater than twice the corresponding height of the mold cavity.

Thus, when the temperature of the mold surfaces is increased, only the two end surfaces 12 are felted. This corresponds substantially to the height of the mold (23 mm). The porous material is thus felted over around 11.5 mm on either side of a central part of the body 10 which will remain substantially nonfelted. The felted thickness has a firmness (or felting ratio) of greater than 2 while the rest of the body has a firmness of 1.

Preferably, the felting crust or skin will have a thickness greater than 0.5 mm, preferably greater than 1 mm, or even greater than 2 mm, in order to obtain a skin that is sufficiently rigid with respect to the main body.

Advantageously, the felting crust or skin will have a thickness less than 5 mm, preferably less than 2 mm, in order to keep the maximum porous material nonfelted.

On account of the shape of the mold and a minimum radius of deformation of the material inside the mold, the felted end surfaces 12 have a slightly domed surface.

Moreover, the felting of the end surfaces 12 results in a significant reduction in the size of the pores of the porous material at the felted layer. Thus, the end surfaces 12 are more or less impermeable to the liquid absorbed into the main body 10 and the applicator can be compressed with a limited quantity of liquid emerging from the end surfaces 12.

The applicator 1 is used as follows:

First of all, the user disposes a quantity of liquid cosmetic product on the lateral surface 11 of the body 10 of the applicator 1. As indicated above, the liquid cosmetic product may already be in a liquid form or be in the form of a dissolved solid (for example powder or paste). In the latter case, the user will add a quantity of solvent, in particular water, to the solid product.

The cosmetic product is notably a foaming cosmetic product.

Loaded with cosmetic product in this way, the user grasps the applicator 1 by the end surfaces 12 forming stiff eners.

Preferably, the applicator 1 is grasped in one hand, notably between a thumb and at least one finger from an index finger and a middle finger.

The user then carries out alternate compressing and releasing movements of the body 10 so as to foam up the cosmetic product.

Once the foam has been sufficiently developed, the user applies the cosmetic product foam by bringing the lateral application surface 11 into contact with a body surface to be treated, notably a surface of the face.

Advantageously, during the application step, the applicator 1 is grasped and compressed so as to have a part of its lateral application surface 11 stretched and an opposite part of its application surface 11 squeezed, compared with a rest configuration of the main body 10.

Claims

1. An applicator (1) for applying a cosmetic product, notably a foaming cosmetic product, in particular a cleansing or care product, comprising an elongate main body (10) made from an open-cell porous material that is elastically compressible in at least a substantially longitudinal direction of said elongate body, and having a lateral application surface (11) and two opposite end surfaces (12), said applicator being characterized in that both opposite end surfaces of the main body comprise a stiffener that is intended for gripping and has a rigidity that is higher relative to the main body.

2. The applicator (1) as claimed in claim 1, characterized in that the stiffener covers the entire end surface (12).

3. The applicator (1) as claimed in any one of claims 1 or 2, characterized in that the main body (10) defines a substantially cylindrical overall envelope.

4. The applicator (1) as claimed in any one of claims 1 to 3, characterized in that the lateral application surface (11) extends over at least half the periphery of the main body (10), preferably over the entire main body.

5. The applicator (1) as claimed in any one of claims 1 to 4, characterized in that the main body (10) has at least one longitudinal groove (15).

6. The applicator (1) as claimed in any one of claims 1 to 5, characterized in that the main body (10) is produced from a foam, in particular a polyurethane foam.

7. The applicator (1) as claimed in any one of claims 1 to 6, characterized in that the stiffener is impermeable to the cosmetic product.

8. The applicator as claimed in any one of claims 1 to 7, characterized in that the stiffener is in the form of a plate attached to the end surface (12) of the main body (10), said end plate being notably produced from a thermoplastic material of the polyethylene or polypropylene type.

9. The applicator (1) as claimed in any one of claims 1 to 8, characterized in that at least one stiffener is an integral part of the main body (10).

10. The applicator (1) as claimed in claim 7, characterized in that the stiffener is produced by permanent compression of a thickness of the main body (10).

11. A method for using an applicator (1) as claimed in any one of claims 1 to 10, characterized in that it comprises the steps of:

- disposing a quantity of cosmetic product, notably a foaming cosmetic product, in particular a cleansing or care product, on the lateral surface (11) of the main body (10) of the applicator,

grasping the applicator by its end stiffeners,

carrying out alternate compressing and releasing movements so as to foam up the cosmetic product,

12. The method as claimed in claim 11, characterized in that the applicator (1) is grasped in one hand, notably between a thumb and at least one finger from an index finger and a middle finger.

13. The method as claimed in claim 12, characterized in that, during the application step, the applicator (1) is grasped and compressed so as to have a part of its lateral application surface (11) stretched and an opposite part of its application surface squeezed, compared with a rest configuration of the main body (10).