WO2019175088A1

WO2019175088A1 - Cosmetic composition refill

Info

Publication number: WO2019175088A1
Application number: PCT/EP2019/055987
Authority: WO
Inventors: Stefania Nuzzo; Mélissa CHAMPEAUX; Gabin Vic; Frédéric Woodland
Original assignee: SEB SA; LOreal SA
Current assignee: SEB SA; LOreal SA
Priority date: 2018-03-15
Filing date: 2019-03-11
Publication date: 2019-09-19
Anticipated expiration: 2020-09-15
Also published as: FR3078871A1; FR3078871B1; US20210030135A1; CN111885941A; EP3764838A1

Abstract

Cosmetic composition refill (20) for a hair treatment device (1), comprising an applicator member (26) initially saturated with liquid cosmetic composition and having an application surface (35) for the composition, said application surface (35) being intended to be placed in contact with a lock of hair during the treatment, and: when the quantity by weight of liquid cosmetic composition initially contained in the refill (20) is greater than 4 g, a discontinuous distribution of the cosmetic composition on the application surface (35) before the first use, with less than 90% of the application surface (35) occupied by the composition before the first use, or when the quantity by weight of liquid cosmetic composition initially contained in the refill (20) is less than or equal to 4 g, a continuous distribution of the composition on the application surface (35) before use, with more than 90% of the application surface (35) occupied by the composition before use.

Description

COSMETIC COMPOSITION REFILL

Technical field

The present invention relates to cosmetic hair product refills for hair treatment devices, and more particularly, but not exclusively, those for devices for shaping the hair, notably intended for straightening, curling or crimping the hair.

The invention also relates to devices provided with such a refill and to methods for treating the hair.

Technological background

Usually, hair straighteners consist of two arms that are connected together with the aid of a hinge which makes it possible to open and close said arms, and of at least one heating element disposed on the arms. During operations of styling a lock of hair, said lock is introduced between the two arms in the open position and then the two arms are closed manually over the lock of hair. The latter is then subjected to the heat output by the heating element, until the two arms are opened and the lock of hair is removed.

Some straighteners also permit application of a cosmetic product to the hair fibres.

This is the case, for example, in the international application WO 2009/078046, which describes a hairstyling appliance comprising two arms that are connected together so as to allow the appliance to be opened and closed, at least one heating member and at least one seat for accommodating a hair treatment device, the latter allowing a haircare product to be dispensed during operation. The hair treatment device comprises a support material impregnated with a haircare product and suitable for a single use.

WO 2009/015027 and US 2009/0025247 also disclose a hair-straightening device that makes it possible to apply a haircare product by contact with the hair. The haircare product to be applied is contained in a removable refill for the application thereof. Said removable refill comprises a reservoir containing the haircare product in a gelled form, and orifices for dispensing and applying the product, said orifices being made directly through a wall of the reservoir. The refill is introduced into a housing disposed on one of the two arms of the hair straightener, by sliding. The application WO 2013/045331 likewise discloses an applicator for applying a care substance to the hair, comprising a cartridge of care substance held in a housing of the applicator. The cartridge comprises a porous support saturated with the care substance.

The application WO 2013/090896 relates to a hair treatment appliance, in particular a hairstyling appliance, comprising a treatment agent holder, notably a saturated porous material, to be applied to the hair or the skin. The holder is fixed to an accessory, which is itself mounted in a removable manner on a hair treatment appliance. The holder is T-shaped, allowing it to be mounted in a complementary groove in the accessory.

The application WO 2013/045331 likewise describes a care product applicator for applying a care product to the hair, and a care product cartridge intended to be used in such an applicator.

The application WO 2014/064660 relates to a device for treating hair, comprising a receptacle containing a product in a fluid state to be applied, two jaws that are movable in relation to each other and can adopt a spread configuration for the insertion of a lock of hair therebetween and a closed configuration for treating the lock of hair, said jaws being movable along the lock of hair in said closed configuration, an application body for applying the cosmetic product, carried by one of said jaws and suitable for coming into contact with the hair in the closed position and a steam outlet on the other one of said jaws, for exposing the hair engaged in the device to the steam.

There is a need to further improve haircare product refills, and the devices permitting application of a haircare product, in order to ensure adequate application of cosmetic product, whether the refills are for single use or multiple use.

In particular, the invention aims to make available a cosmetic refill with improved filling, permitting efficient, uniform and reproducible delivery of a cosmetic composition intended for hair treatment, with greater tolerance as regards the conditions, notably the temperature conditions, in which the refill is stored prior to treatment.

Summary of the invention

Cosmetic composition refill

According to a first of its aspects, the present invention thus relates to a cosmetic composition refill for a hair treatment device, comprising an applicator member initially saturated with liquid cosmetic composition and having a composition application surface intended to be placed in contact with a lock of hair during the treatment, and: - when the quantity by weight of liquid cosmetic composition initially contained in the refill is greater than 4 g, a discontinuous distribution of the cosmetic composition on the application surface before the first use, with less than 90% of the application surface occupied by the composition before the first use,

or

- when the quantity by weight of liquid cosmetic composition initially contained in the refill is less than or equal to 4 g, a continuous distribution of the composition on the application surface before use, with more than 90% of the application surface occupied by the composition before use.

By virtue of the invention, it has been observed that, despite storage conditions of the refill of up to two months at 45°C, satisfactory stability and uniformity of distribution on the hair were obtained during use.

The expression“continuous distribution of the composition on the application surface” signifies a uniform presence on the application surface before use of the refill.

The expression “discontinuous distribution of the composition on the application surface” signifies a discrete presence on the application surface before use of the refill; in particular, the application surface may comprise non-interconnected regions where the composition is present, said regions being separated by regions where the composition is absent. The distribution of the composition is advantageously regular, that is to say the regions with composition are identical to each other and are equally distributed on the application surface.

The “initial degree of occupation of the application surface by the composition” is the percentage indicated above, which is less than 90% for a refill initially containing more than 4 g of composition, and which is greater than 90% for a refill initially containing 4 g or less than 4g of composition.

The cosmetic composition is a cosmetic haircare product applied in liquid form. The expression“cosmetic haircare product” denotes a composition comprising one or more active ingredients for haircare use, and in particular a product as defined in directive 93/35/EC dated 14 June 1993. Water in liquid or gaseous form which does not contain any additives for haircare use does not constitute a cosmetic product within the meaning of the present invention. The cosmetic product may be intended to make it easier to shape the hair. Examples of active ingredients are given for example in the publication US 2010/0307528 Al, in paragraphs [0031] and [0032] The product is preferably anhydrous. The product is preferably an oil-based product.

When the initial quantity by weight of liquid cosmetic composition is greater than 4 g, the refill is a multiple-use refill, that is to say it can be used for at least two applications by a user. In this case, the flow rate of composition on paper is preferably between 0.07 g/m and 0.09 g/m on a length corresponding to at least two applications, on the basis of 30 passes per application. The protocol for measuring the flow rate is described below.

When the initial quantity by weight of liquid cosmetic composition is less than or equal to 4 g, the refill is a single-use refill, i.e. it can be used only for one application, on the basis of 30 passes of the refill over the hair. In this case, the flow rate of composition on paper is preferably between 0.07 g/m and 0.59 g/m on the length corresponding to one application, on the basis of 30 passes for this application.

By virtue of the invention, regardless of whether the refill is a single-use or multiple-use refill, the inventors have determined, on the basis of numerous tests, that the refill according to the invention allows cosmetic composition to be delivered to the hair in a manner that is efficient, uniform and reproducible, with great tolerance as regards the conditions in which the refill is stored before treatment, notably the duration of storage, the positioning of the refill during storage, and the storage temperature. In particular, the composition remains sufficiently stable and homogeneous in the refill for a period of two months at 45°C.

Preferably, the applicator member is entirely porous.

The applicator member is made in particular of felt. In the latter case, the fibres of the felt can all be oriented substantially in the same direction, the fibres preferably being oriented perpendicularly to the surface of the lock of hair to be treated or parallel to a longitudinal direction of the applicator member.

The density of the applicator member is, for example, greater than 0.11 g/cm³ and less than 0.250 g/cm³.

The applicator member can have an elongate form, with a cross section in the shape of a rectangle or cross, and with one end forming the application surface intended to be in contact with the hair to be treated. The application surface is preferably flat. The application surface can have a rectangular shape. The application surface can have a greater dimension, notably a length, of between 50 mm and 150 mm and a smaller dimension, notably a width, of between 5 mm and 30 mm. The applicator member can be parallelepipedal. The dimensions of the applicator member are for example 8 mm x 20 mm x 90 mm, the application surface having dimensions of 8 mm x 90 mm.

The applicator member is made at least partially, better still entirely, of polyethylene, of polypropylene, or of a mixture of polyethylene and polypropylene, the mixture preferably comprising between 45 and 55% polyethylene by weight and between 55 and 45% polypropylene by weight, notably 50% polyethylene and 50% polypropylene.

The cosmetic composition at least partially saturating the applicator member is advantageously an anhydrous composition, of which the viscosity can be between 100 centipoise and 600 centipoise, preferably between 100 centipoise and 500 centipoise, better still between 100 centipoise and 120 centipoise, or even between 100 centipoise and 115 centipoise. The viscosity of the composition is measured at a pressure of 1013.25 hPa, at a temperature of 22°C and at a shear rate of 1 s ¹. The viscosity may be measured using a cone/plate viscometer, notably using a Haake R600 rheometer or a similar device.

An“anhydrous composition” is understood here to be a composition containing less than 5% by weight of water, and more preferably less than 1% by weight of water, relative to the total weight of the composition. Preferably, the anhydrous composition does not contain any water added during the preparation of the composition, the only water present originating from the residual water provided by the mixed ingredients. Even more preferably, the anhydrous composition is free of water.

The cosmetic composition, when it consists of an anhydrous composition, advantageously comprises one or more natural or synthetic oils.

The natural oils may be chosen from among mineral oils and plant oils. The mineral oils may be chosen from mixtures of hydrocarbon-based oils derived from petroleum, volatile or non-volatile liquid paraffin, liquid petroleum jelly, polyolefins. The natural oils may be chosen from plant oils, preferably chosen from triglyceride plant oils.

The synthetic oils may be chosen from silicone oils, preferably from linear, branched or cyclic, volatile or non-volatile, optionally organomodified silicone oils. Silicone is understood to mean compounds comprising one or more atoms of silicon in their structure. When anhydrous, the cosmetic composition may comprise one or more silicone oils, preferably in a content of between 0.05% and 99.9% by weight, relative to the total weight of the composition.

When it is anhydrous and comprises at least one oil, the cosmetic composition advantageously comprises one or more oils in a content ranging from 1% to 100%, preferably from 5% to 99%, more preferably from 10% to 99%, better still from 25% to 99% and even better still from 50% to 99% by weight relative to the total weight of the composition.

The cosmetic composition may also comprise one or more ingredients chosen from natural or synthetic waxes, cationic, nonionic, anionic or amphoteric non-silicone polymers, UV-screening agents, colorants, surfactants, pigments, preservatives, and fragrances.

The applicator member may be saturated with cosmetic composition with an initial degree of filling of less than or equal to 90% and/or greater than 30%.

The expression“initial degree of filling” signifies the ratio between the volume occupied by the composition after filling, notably by absorption or injection by needle, and before use of the refill, and the total volume of the applicator member.

The refill may comprise a body delimiting a cavity that is formed at least partially by two opposite walls and a bottom and opens towards the outside by way of an opening, the applicator member being partially received in the cavity and extending partially out of the cavity, through the opening.

Cosmetic article

According to another aspect, in combination with the preceding one, the invention relates to a cosmetic article comprising a closed package and at least one cosmetic composition refill as defined above, contained in the package.

Device for treating hair

The invention also relates to a hair treatment device, comprising:

- at least one arm,

- a cosmetic composition refill as defined above, which is mounted on the arm.

Preferably, the refill is disposed in a removable manner in a housing of the arm. Preferably, the hair treatment device comprises two arms that are movable relative to each other between a moved-together configuration for treating the hair and a spaced-apart configuration for inserting hair to be treated between said arms.

The device may also comprise, on at least one of the arms, at least one heating element.

The device is preferably a hair straightener, notably a straightening iron.

Hair treatment unit

According to another aspect, the invention relates to a ready-to-assemble hair treatment assembly, comprising:

- a hair treatment device, comprising at least one arm provided with a heating element for the hair, the hair treatment device comprising, on one of these arms, a receiving housing suitable for receiving a cosmetic composition refill as defined above, and

- a cosmetic article as defined above, in all the combinations thereof.

Hair treatment method

According to another aspect, the invention relates to a method for treating the hair, comprising the step of applying a cosmetic composition to a lock of hair with the aid of the device according to the invention.

Brief description of the figures

The invention may be better understood from reading the following detailed description of non-limiting illustrative embodiments thereof and from examining the appended drawing, in which:

Figure 1 shows a perspective and schematic view of an example of a hair treatment device,

Figure 2 is a schematic cross-sectional view on II-II in Figure 1,

Figure 3A is a schematic side view of an example of an applicator member, viewed in isolation, that can be employed in the hair treatment device in Figure 1,

Figure 3B is a schematic view of the application surface on IIIB in

Figure 3A,

Figure 4A is a schematic side view of a comparison example of an applicator member, viewed in isolation, not included in the invention, Figure 4B is a schematic view of the application surface on IVB in

Figure 4 A,

Figure 5A is a schematic side view of another comparison example of an applicator member, viewed in isolation, not included in the invention,

Figure 5B is a schematic view of the application surface on VB in

Figure 5A,

Figure 6A is a schematic side view of an example of an applicator member, viewed in isolation, that can be employed in the hair treatment device in Figure 1,

Figure 6B is a schematic view of the application surface on VIB in

Figure 6 A,

Figure 7A is a schematic side view of an example of an applicator member, viewed in isolation, that can be employed in the hair treatment device in Figure 1,

Figure 7B is a schematic view of the application surface on VIIB in

Figure 7A,

Figure 8 schematically illustrates two graphs with different curves showing the flow rate as a function of the number of passes carried out on the basis of measurements made on the applicator member from Figure 3A after different storage conditions,

Figure 9 is a graph showing a curve of the flow rate as a function of the number of passes carried out on the basis of measurements made on the applicator member from Figure 3A under given conditions,

Figure 10 schematically illustrates graphs similar to those of Figure 8 for the examples of applicator members shown in Figures 3A, 3B, 4A, 4B, 5A, 5B, 6A, 6B and 7A, 7B, and

Figure 11 is a schematic view of an example of a ready-to-assemble assembly for treating the hair.

Detailed description of embodiments of the invention

In the rest of the description, identical elements or elements having identical functions bear the same reference sign. In order to make the present description concise, they are not described for each of the figures, only the differences between the embodiments being described.

Figures 1 and 2 show a handpiece 2 of an example of a hair treatment device 1.

This handpiece 2 has two jaws 3 and 4 that are movable with respect to each other between a spaced-apart configuration (not shown) for introduction of a lock of hair between said jaws, and a moved-together configuration, shown in Figure 1, for treating the lock of hair.

The jaws 3 and 4 are carried by an upper arm 5 and a lower arm 6, respectively, which, in the example in question, are connected together at one end by an articulation 8, the handpiece 2 thus forming tongs.

The upper arm 5 and lower arm 6 each preferably have a total length of between 22 cm and 37 cm and define, between the articulation 8 and the jaws 3 and 4, respective half- handles 10 and 11 on which the user can press in order to move the jaws 3 and 4 together.

An elastic return member (not visible) is preferably provided to return the jaws 3 and 4 to a spaced-apart configuration, this elastic return member being for example a spring disposed around an articulation pin 8.

The invention is not limited to a particular manner of connecting the upper arm 5 and lower arm 6 together, and the jaws 3 and 4 may be rendered movable in some other way without departing from the scope of the present invention. However, the presence of an articulation is largely preferred for the ergonomics it provides.

The jaws 3 and 4 define between them a region for treating the hair, said region being intended to receive a lock of hair to be treated, the handpiece 2 being moved along said lock during the treatment, for example in the direction from the root to the end of the hair.

In the example in question, the handpiece 2 is configured to apply a cosmetic composition, to treat the hair by way of steam and then to carry out a heat treatment of the hair by contact with two hot surfaces of heating elements 15 and 16 that are carried by the upper arm 5 and the lower arm 6, respectively.

The direction D of movement of the handpiece 2 over the hair, illustrated in Figure 1 or 2, is preferably substantially perpendicular to the upper arm 5 and lower arm 6 and to the longitudinal axis of the device. The handpiece 2 is connected by a line 18, in the example in question, to a base station (not shown) that is fixed during the treatment and is connected to the mains.

This base station provides the electric power supply to the handpiece 2 and also its supply with water in order to generate steam, and may also carry out additional functions of processing electrical signals received from the handpiece 2. The line 18 which connects the handpiece 2 to the base station can thus comprise various electrical conductors and a water supply pipe.

A user interface (not shown in the figures) can be present on the handpiece 2 so as to allow the user for example to start up certain components thereof, or not.

The cosmetic product is applied by a refill 20 carried by one of the two arms, 5 or 6, in this case the upper arm 5, which comes into contact with a pressing element 21. The latter may be removable.

The refill 20 comprises a body 23 and an applicator member 26 disposed so as to come into contact with the hair extending through the treatment region.

The refill 20 may be fastened to the arm 5 or 6 by any means, notably, as illustrated in Figure 2, by sliding a rib of the body 23 into a groove with a complementary shape.

As illustrated in Figure 2, the body 23 has a cavity 30 that opens towards the outside by way of an opening 31 into which the applicator member 26 is inserted, along an insertion axis X, while the refill is being manufactured. More specifically, the cavity 30 is formed at least partially by two opposite lateral walls 34, 36, parallel to the longitudinal axis of the device, and by a bottom 37 of the body 23. The applicator member 26 is partially received in the cavity 30 and extends partially out of the latter, through the opening 31. The body 23 may comprise coupling reliefs that extend into the cavity 30.

The body 23 substantially has an elongate shape along the longitudinal axis of the device. In cross section, the body 23 is U-shaped, as illustrated in Figure 2.

As illustrated in Figure 2, the applicator member 26 may be in the form of a rectangular parallelepiped. The applicator member 26 thus has a substantially flat application surface 35 that is intended to be in contact with the hair to be treated. The dimensions of the applicator member 26 are for example 8 mm x 20 mm x 90 mm, the application surface 35 intended to be in contact with the hair having dimensions of 8 mm x 90 mm. In the example illustrated, the applicator member 26 is porous. It comprises, for example, a mixture of 50% polyethylene and 50% polypropylene.

In this embodiment, the material from which the applicator member 26 is made is a felt. The fibres of the felt may be oriented parallel to the surface of the lock of hair to be treated, the fibres preferably being oriented substantially in a longitudinal direction of the applicator member, perpendicularly to the direction D of passage over the hair. In one variant, the fibres of the felt of the applicator member are oriented perpendicularly to the surface of the lock of hair to be treated, i.e. perpendicularly to the direction D and to the longitudinal direction of the applicator member 26.

By way of examples or comparison examples, five applicator members have been shown in Figures 3A to 7B.

Examples:

Cosmetic composition C below was prepared from the ingredients indicated in the table below. The concentrations are expressed as weight percentages of active material in the composition.

This anhydrous cosmetic composition has a viscosity of 113 centipoise at

22°C.

First sample tested

Figures 3A and 3B show, on its own, an example of an applicator member 26 that can be used in the refill 20 in the hair treatment device 1. This is the first sample El .

The density of the porous material from which the applicator member 26 is made is 0.180 g/cm³.

In this embodiment, the initial quantity by weight of cosmetic composition C, before use, is 3 g.

The initial degree of absorption of cosmetic composition C in the applicator member is 30%. The initial degree of occupation of the application surface 35 by the cosmetic composition C, as can be seen in Figure 3B, is 100%. The distribution of the cosmetic composition C on the application surface is continuous, the cosmetic composition C being shown in Figures 3A and 3B by hatching. Second sample tested, comparison example

Figures 4 A and 4B show, on its own, an example of an applicator member 26’ (given as a comparison example) that can be used in a refill in a similar hair treatment device. This is the second sample E2.

The density of the porous material from which the applicator member 26’ is made is 0.210 g/cm³.

In this embodiment, the initial quantity by weight of cosmetic composition C, before use, is 10.5 g.

The degree of absorption of cosmetic composition C in the applicator member is 100%. The initial degree of occupation of the application surface 35’ by the cosmetic composition, as can be seen in Figure 4B, is 100%. The distribution of the cosmetic composition C on the application surface is continuous, the cosmetic composition C being shown in Figures 4 A and 4B by hatching.

Third sample tested, comparison example

Figures 5 A and 5B show, on its own, another example of an applicator member 26’ (given as a comparison example) that can be used in a refill in a similar hair treatment device. This is the third sample E3.

In this embodiment, the initial quantity by weight of cosmetic composition C, before use, is 7.7 g.

The initial degree of absorption of cosmetic composition C in the applicator member 26’ is 70%. The initial degree of occupation of the application surface 35’ by the cosmetic composition C, as can be seen in Figure 5B, is 100%. The distribution of the cosmetic composition C on the application surface is continuous, the cosmetic composition C being shown in Figures 5A and 5B by hatching.

Fourth sample

Figures 6A and 6B show, on its own, an example of an applicator member 26 that can be used in the refill 20, in the hair treatment device 1. This is the fourth sample E4.

The density of the porous material from which the applicator member 26 is made is 0.210 g/cm³. In this embodiment, the initial quantity by weight of cosmetic composition C, before use, is 3 g.

The initial degree of absorption of cosmetic composition C in the applicator member is 30%. The initial degree of occupation of the application surface 35 by the cosmetic composition C, as can be seen in Figure 6B, is 100%. The distribution of the cosmetic composition C on the application surface is continuous, the cosmetic composition C being shown in Figures 6A and 6B by hatching.

Fifth sample

Figures 7A and 7B show, on its own, an example of an applicator member 26 that can be used in the refill 20, in the hair treatment device 1. This is the fifth sample E5.

The density of the porous material from which the applicator member 26 is made is 0.210 g/cm³.

The initial degree of absorption of cosmetic composition C in the applicator member is 70%. The initial degree of occupation of the application surface 35 by the cosmetic composition C, as can be seen in Figure 7B, is 50%. The distribution of the cosmetic composition C on the application surface is discontinuous, the cosmetic composition C being shown in Figures 7A and 7B by hatching.

For all the samples, the applicator members have a parallelepipedal shape with fibres oriented substantially in a longitudinal direction of the applicator member, parallel to the surface to which the cosmetic composition is applied. They are composed of a felt comprising a mixture of 50% polyethylene and 50% polypropylene.

For the first, fourth and fifth samples, in order to introduce the cosmetic composition C into the applicator member 26, use has been made at the factory of a conventional method for injecting the composition with the aid of needles inserted into the material.

For the second and third samples, the applicator member has been placed into a composition which it has absorbed. The exact quantity of composition needed has been provided, notably to impregnate the applicator member of the third sample by 70%. The “initial quantity” is understood here to be the quantity of cosmetic composition present in the applicator member or at the application surface before use, that is to say before the first pass over the hair to be treated.

The“degree of absorption of cosmetic composition in the applicator member” is understood to be the ratio between the mass of cosmetic composition effectively present in the applicator member and the maximum mass of composition that the applicator member is able to absorb. This degree of absorption is measured at atmospheric pressure of 1.01325 * 10⁵ Pa and a temperature of 22°C.

The“initial degree of occupation of the application surface by the cosmetic composition” is understood to be the ratio between the surface area of cosmetic composition effectively present at the application surface and the total surface area of the application surface before use, that is to say before the first pass over the hair to be treated.

The test to which the different applicator members are subjected entails:

- storing applicator members according to the five samples tested under all or some of the following different conditions: 0 month at ambient temperature of 25°C, 0.5 month at a temperature of 45°C, 1 month at ambient temperature of 25°C, 2 months at temperature of 45°C and 2 months at ambient temperature of 25°C, and, for each sample tested, the applicator member being disposed with the application surface facing downward or upward;

- for each of the samples stored under the conditions listed above, performing the flow rate measurement protocol that is to say: carrying out fifteen passes of 15 seconds each of the applicator member, placed on the treatment device, over strips of paper of 80g/m² from the manufacturer Clairefontaine, each strip measuring 27 cm in length and 10.5 cm in width, a force of 35 N +/- 2 being applied to the treatment device, in the direction of the strip of paper, so as to deliver a quantity of cosmetic composition onto the fifteen strips. The flow rate of cosmetic composition C can be measured every five passes, for example by weighing the applicator member at every five passes.

It is important to note that the strips have to be saturated along their entire length. In other words, the applicator member is moved over the strip at a speed of around 1.8 cm/s. The result obtained for the first sample has been illustrated in Figure 8. The result obtained for the first, second, third, fourth and fifth samples, respectively El, E2, E3, E4 and E5, has been shown in Figure 10.

For the first sample El, one hundred passes similar to those described above were also made on strips of paper, with the applicator member being weighed at every five passes. The resulting graph has been illustrated in Figure 9.

Figure 8 shows two graphs labelled E1B and E1H. The graph E1B was obtained after storing the applicator member with the application surface facing downwards, while the graph E1H was obtained after storing the applicator member with the application surface directed upwards.

On each of these graphs, and also on the graphs in Figures 9 and 10, the abscissa axis represents the number of passes n, while the ordinate axis represents the mass flow rate g of the composition, that is to say the quantity of cosmetic composition deposited on the strip of paper according to the protocol specified above. Therefore, these graphs in Figures 8 to 10 indicate the mass flow rate of the cosmetic composition C as a function of the number of passes carried out.

On each of these graphs:

- the curve a corresponds to measurements performed at 0 month of storage at ambient temperature;

- the curve b corresponds to measurements performed at 0.5 month of storage at a temperature of 45°C;

- the curve c corresponds to measurements performed after 1 month of storage at a temperature of 45°C;

- the curve d corresponds to measurements performed after 1 month of storage at ambient temperature;

- the curve e corresponds to measurements performed after 2 months of storage at a temperature of 45°C; and

- the curve/ corresponds to measurements performed after 2 months of storage at ambient temperature.

The curves h and i in plain dashed lines delimit between them the zone Z of acceptability measured in vivo. If the curves a to/ are essentially within this zone Z, then, despite the different storage conditions, the distribution of cosmetic composition can be considered to be stable and uniform.

Thus, it is noted that the first, fourth and fifth samples corresponding to the graphs E1B, E1H, E4B, E4H and E5B, E5H, respectively, satisfy this criterion. Indeed, looking at the curves on these graphs, it is seen that the curves are essentially located within the zone Z, between the curves Zl and Z2.

However, as regards the second and third samples, corresponding to the graphs E2B, E2H, E3B and E3H respectively, these do not satisfy the criterion according to which the curves a to/ are essentially within the zone Z of acceptability. Consequently, they are not acceptable for the desired stability.

The first and fourth samples correspond to a single-use refill, the initial quantity of cosmetic composition C being less than 4 g.

The fifth sample corresponds to a multiple-use refill permitting at least two uses, the initial quantity of cosmetic composition C being greater than 4 g.

The graph in Figure 9 shows the curve illustrating the number of possible passes with the applicator member according to the first sample. One use has been realized after approximately 30 passes. However, when the flow rate is less than 0.07g/cm³, the quantity of composition deposited is insufficient. This is why Figure 9 illustrates the fact that only a single use can be effected, i.e. approximately 30 passes, with the first sample.

It has thus been found that, for a single-use refill (initial quantity of composition less than 4 g), the best stability of distribution of the applicator member, regardless of the length of storage (between 0 month and 2 months) and the temperature (between ambient temperature and 45°C), is obtained with an applicator member whose application surface is occupied to at least 90% by the composition, distributed continuously.

It has also been found that, for a multiple-use refill (initial quantity of composition greater than 4 g), the best stability of distribution of the applicator member, regardless of the length of storage (between 0 month and 2 months) and the temperature (between ambient temperature and 45°C), is obtained with an applicator member whose application surface is occupied to at least 90% by the composition, distributed discontinuously.

The invention is not limited to the examples that have just been described. Thus, the invention also relates to a ready-to-assemble assembly 200 as illustrated schematically in Figure 11. This ready-to-assemble assembly 200 comprises a hair treatment device 1 and a cosmetic article 202. This article comprises a cosmetic product refill 20 in a package 204 which is closed so as to avoid, notably, any evaporation of the cosmetic product from the applicator member. In a variant, the package 204 may comprise a plurality of cosmetic product refills 20. In this case, it is preferred for the package to be able to be reclosed so that the other cosmetic product refills do not dry out when a refill is withdrawn from the package. In a variant, in this case, each individual refill is preserved in an individual package, inside a package common to the multiple refills.

Claims

1. Cosmetic composition refill (20) for a hair treatment device (1), comprising an applicator member (26) initially saturated with liquid cosmetic composition and having a composition application surface (35) intended to be placed in contact with a lock of hair during the treatment, and:

- when the quantity by weight of liquid cosmetic composition initially contained in the refill (20) is greater than 4 g, a discontinuous distribution of the cosmetic composition on the application surface (35) before the first use, with less than 90% of the application surface (35) occupied by the composition before the first use,

or

- when the quantity by weight of liquid cosmetic composition initially contained in the refill (20) is less than or equal to 4 g, a continuous distribution of the composition on the application surface (35) before use, with more than 90% of the application surface (35) occupied by the composition before use.

2. Refill (20) according to Claim 1, the initial quantity by weight of liquid cosmetic composition being greater than 4 g, in which the flow rate of composition on paper is between 0.07 g/m and 0.9 g/m on the length corresponding to at least two applications, on the basis of 30 passes per application.

3. Refill (20) according to Claim 1, the initial quantity by weight of liquid cosmetic composition being less than or equal to 4 g, in which the flow rate of composition on paper is between 0.07 g/m and 0.59 g/m on the length corresponding to one application, on the basis of 30 passes for this application.

4. Refill (20) according to any one of the preceding claims, in which the applicator member (26) is entirely porous.

5. Refill (20) according to any one of the preceding claims, in which the applicator member (26) is made of felt.

6. Refill (20) according to Claim 5, the fibres of the felt all being oriented substantially in the same direction, the fibres preferably being oriented perpendicularly to the surface of the lock of hair to be treated or parallel to a longitudinal direction of the applicator member (26).

7. Refill (20) according to any one of the preceding claims, in which the density of the applicator member (26) is greater than 0.11 g/cm³ and less than 0.250 g/cm³.

8. Refill (20) according to any one of the preceding claims, in which the applicator member (26) has an elongate form, with a cross section in the shape of a rectangle or cross, and with one end forming the application surface intended to be in contact with the hair to be treated, the application surface being flat.

9. Refill (20) according to any one of the preceding claims, in which the applicator member (26) is made at least partially, better still entirely, of polyethylene, of polypropylene, or of a mixture of polyethylene and polypropylene, the mixture preferably comprising between 50% polyethylene and 50% polypropylene by weight.

10. Refill (20) according to any one of the preceding claims, in which the liquid cosmetic composition is an anhydrous composition, notably comprising an oil, of which the viscosity is preferably between 100 centipoise and 600 centipoise.

11. Refill (20) according to any one of the preceding claims, comprising a body (23) delimiting a cavity (30) that is formed at least partially by two opposite walls (34, 36) and a bottom (37) and that opens towards the outside by way of an opening (31), said applicator member (26) being partially received in said cavity (30) and extending partially out of the cavity (30), through the opening (31).

12. Cosmetic article (202) comprising a closed package (204) and at least one cosmetic composition refill (20) according to any one of the preceding claims, contained in the package (204).

13. Hair treatment device (1) comprising:

- at least one arm (5, 6),

- a cosmetic composition refill (20) according to any one of Claims 1 to 11, which is mounted on the arm.

14. Device according to Claim 13, comprising at least one heating element (15, 16), and preferably constituting a hair straightener, notably a straightening iron.

15. Method for treating the hair, comprising the step of applying a cosmetic composition to a lock of hair using a device according to Claim 13 or 14.