Device for treating human keratin materials

Abstract

Device for treating human keratin materials Device for treating keratin materials (K) in contact with a fluid (C), in particular a cosmetic composition, the device comprising: - At least one ultrasonic transducer (4) having an emission surface (S) of acoustic waves in said fluid to generate bubbles therein having a mechanical action when they collapse on said keratin materials, the emission surface having reliefs (420) where the bubbles can originate at different levels along the longitudinal axis (X) of the transducer. Figure for the abstract: Fig. 12a[Fig 1]

Description

Title of the invention: Device for treating human keratin materials Technical field

[0001] The present invention relates to the cleaning of human keratin materials, and more particularly but not exclusively to the treatment of the skin, scalp and / or hair, in particular those which have undergone coloring. Prior art

[0002] Application JP 2007-311756 discloses an ultrasonic cleaning device for cleaning a silicon wafer, a mask substrate, etc. The device comprises an ultrasonic transducer mounted in a nozzle through which a cleaning liquid flows, and means for introducing a gas to generate bubbles in the cleaning liquid.

[0003] Application US 2012 / 0227761 describes a device for cleaning a surface, comprising on the one hand a chamber supplied with a liquid and communicating with an outlet duct opening onto the surface to be cleaned, an ultrasonic transducer transmitting acoustic energy to the liquid contained in the chamber and the outlet duct, and on the other hand a bubble generator for generating bubbles of a gas in the outlet duct. The bubble generator may be an electrochemical generator, the liquid containing for example a salt such as potassium chloride to make the liquid electrically conductive. A surfactant may be added to prevent the bubbles from coalescing as they travel through the outlet duct towards the surface to be treated, and to ensure that they have the required size when they reach the surface to be treated.

[0004] The application of the device to cleaning the skin, in particular under the nails of a surgeon, is envisaged, as well as the hands.

[0005] This application mentions the possible addition of surfactant to influence the size of the bubbles produced. No cosmetic application for treating facial skin or hair is disclosed.

[0006] Application ES 2 708 149 discloses a device for cleaning a surface comprising a sonotrode generating ultrasound near a cleaning solution present on the surface, the cavitation making it possible to remove dirt from the surface.

[0007] Patent US8486199 describes a device for treating a surface of a semiconductor wafer comprising a resonator for providing ultrasonic energy to a treatment fluid containing gas bubbles.

[0008] Document EP 1 645 342 describes a method for cleaning equipment consisting of subjecting a liquid comprising bubbles to an acoustic field.

[0009] Patent KR101152920 describes a skin cleansing device comprising a vacuum pump and intended to be used in proximity to a liquid containing microbubbles on the skin.

[0010] Applications US 2017 0080257, KR 2020 0102956, US 2009 / 318853, JP 2016 214424 and WO 2020 / 029429 disclose methods for cosmetic treatment of the skin, in particular its cleansing, using an ultrasound device which generates microbubbles in a cosmetic composition applied to the skin to be cleansed.

[0011] Similar devices are disclosed in applications US 2011 / 21328, US 2010 / 010420 and EP 3 634 643, CN206995178 and EP 2 470 310.

[0012] Application EP 3 542 740 discloses a medical device for cleaning wounds, comprising a removable cleaning tip and an ultrasonic transducer.

[0013] Some devices involve a significant amount of water and new compositions with each use.

[0014] Eco-design of products by promoting the sustainable use of resources is becoming an essential key factor in minimizing the impact of products on the environment. Producers are empowered and encouraged by changes in consumer habits to eco-design their formulas and packaging, while ensuring that industrial processes are optimized and production waste is managed. A virtuous circle is thus structured. Similarly, supporting consumers towards greater sobriety is part of this global movement towards individual responsibility.

[0015] There is therefore a need for products with a reduced environmental footprint, which can meet the increasingly real expectations of consumers.

[0016] Furthermore, when one wishes to apply a coloring treatment to already colored hair, it may be desirable to bleach it beforehand; such a bleaching treatment must, however, ideally be carried out without damaging the hair fiber.

[0017] However, bleaching is currently carried out using compounds that have a chemical action on the hair, such as oxidants, which can have an impact on the environment, and it would be desirable to avoid the use of these compounds or to reduce their quantities. In addition, these compounds can have a relatively aggressive action on the hair fiber.

[0018] Indeed, hair coloring or bleaching treatments are generally carried out using an oxidizing agent, such as hydrogen peroxide, a potassium, sodium, ammonium, perborate or percarbonate salt, persulfate or percarbamide, in an alkaline solution. The oxidizing agents used in these Hair treatments generally cause a breakdown of the disulfide bonds that connect the keratin chains. Repeated treatments with oxidizing agents therefore often result in hair becoming fragile and brittle, and losing its shine.

[0019] Conditioning agents, such as silicones, cationic surfactants or cationic polymers, have been proposed to be applied to the hair after rinsing the composition containing the oxidizing agents.

[0020] These conditioning agents help to reduce damage to the hair by creating a protective film, which improves the feel of the hair, but do not prevent premature hair breakage that can be caused by successive oxidative treatments. Furthermore, these conditioning agents have a significant impact on the environment.

[0021] Many solutions have been proposed to try to respond to this problem.

[0022] US 5,100,436 thus discloses hair dye compositions comprising metal-chelating complexes allowing a reduction in the exposure time of the hair to oxidizing compositions, thus reducing the damage caused by the oxidizing agent. US 6,013,250 discloses a composition for treating hair against chemical damage and photo-damage. US 4,138,478 discloses the use of a particular compound for reducing the damage done to the hair during bleaching or coloring. US 3,202,579 and US 3,542,918 disclose other protective compounds. US 5,635,167 discloses a method for removing exogenous metal ions attached to the hair, comprising a step of contacting the hair with a mixture of chelating agents. WO97 / 24106 discloses hair coloring compositions comprising a bleaching adjuvant for reducing damage to the hair at low pH.

[0023] All these solutions rely on the use of particular chemical compounds, and do not fully satisfy the need to improve the environmental footprint of hair coloring and / or bleaching treatments or hair cleaning treatments. Furthermore, they do not completely prevent damage to the hair caused by the action of bleaching agents such as oxidants. Disclosure of the invention

[0024] The invention aims to propose a method for cleaning human keratin materials, in particular facial skin, scalp or hair, making it possible to effectively clean said materials, and forming part of a responsible sustainable development approach, thanks to a reduced carbon footprint.

[0025] The invention also aims to propose a device and a method for processing human hair that minimizes the use of chemical products for bleaching hair, limits the consumption of water and / or active ingredients and the release of harmful substances into the environment, reduces the risks associated with repeated exposure of the hair and scalp to aggressive substances and treatments, and facilitates hair bleaching and coloring treatments. Summary of the invention

[0026] The invention thus relates, according to a first of its aspects, to a method for treating human keratin materials, comprising the step of subjecting a surface of said keratin materials to a cosmetic composition containing at least one surfactant, and to acoustic waves emitted by at least one ultrasonic transducer excited by a pulsed or non-pulsed electrical signal, having at least one frequency component between 20 kHz and 100 kHz, with a Ton / Toff duty cycle when the signal is pulsed preferably between 20 and 100%, with a Ton pulse duration when the signal is pulsed preferably between 0.01 and 1 s, and with an acoustic intensity Isata on said surface preferably at least equal to 0.1 W / cm 2

[0027] In this way, it is possible to generate bubbles within the cosmetic composition in the vicinity of the surface of said materials to be cleaned and cause them to collapse.

[0028] This process is preferably cosmetic for non-therapeutic purposes.

[0029] The term “cosmetic composition” means a composition containing at least one cosmetic active ingredient, as defined in the Cosmetics Directive 76 / 768 / EEC. This may in particular be an active ingredient contributing to the cleaning and / or bleaching of hair, as detailed below. According to the invention, mineral or tap water does not constitute a cosmetic composition.

[0030] By "human keratin materials" is meant external materials such as the skin and appendages, in particular hair and nails, and internal materials such as the gums or other mucous membranes. The treatment can in particular be carried out on the superficial layers of the skin. The area of ​​skin which is treated according to the invention can be the skin of the face, the bust, the back, the arms, the legs, the hands and / or the feet, the scalp. The method according to the invention is particularly suitable for removing make-up and / or cleaning the skin of the face, in particular the forehead, the cheeks, the chin, the neck, the nose, the scalp.

[0031] The method according to the invention may also be suitable for skin or hair care, or for cleaning and / or preparing the skin, hair or scalp, in particular for preparing the hair for a coloring or bleaching treatment.

[0032] By "at least one frequency component" is meant the frequency in its sense classical for a periodic signal whose spectrum comprises a single line, for example of the sinusoidal type, and for a periodic signal whose spectrum comprises several lines, the frequency of at least one line, in particular that of the highest amplitude.

[0033] The acoustic intensity ISata can be defined as the average acoustic power on the surface subjected to the acoustic waves, divided by said surface:

[0034] 1sat a =: m°y / ,

[0035] the average acoustic power being obtained from the activation voltage of the transducer, and the duty cycle when the electrical signal is pulsed.

[0036] The acoustic intensity ISAta is preferably between 0.1 and 10 W / cm2, better still between 1 and 5 W / cm2, even better still between 2.5 and 5 W / cm2, even better still between 3 and 4 W / cm2.

[0037] The method according to the invention, thanks to the aforementioned parameter ranges for the signal, and in particular a minimum ISata acoustic intensity, makes it possible to effectively eliminate or treat both exogenous impurities and endogenous impurities or defects.

[0038] Among the undesirable dirt that may be present on keratin materials (on the surface and / or anchored deeper in the pores of the skin), one can distinguish exogenous impurities such as makeup, environmental pollution, dust, microorganisms, etc., and endogenous impurities or defects such as excess sebum, sweat, dead cells, dead skin, dandruff, blackheads, light scars and / or acne, pigmented spots, etc.

[0039] The acoustic waves obtained by using the aforementioned parameter ranges for the signal make it possible to cause complete cavitation of bubbles within the composition in order to generate a mechanical effect on the keratin materials to be cleaned.

[0040] By "complete cavitation" is meant here both the generation and the collapse of bubbles causing a mechanical shock on the surrounding surfaces. The cosmetic composition may, or may not, have bubbles already present within it before the application of the acoustic waves.

[0041] The bubbles generated and / or present may also contribute to the release of chemical species contributing to the cleaning of keratin materials, such as free radicals. Surfactant

[0042] The composition preferably has a total concentration of surfactant(s) of between 0.01% and 20% by weight relative to the total mass of the composition, better still between 0.01% and 5%, even better still 0.1% and 1.5%; thus, the composition can have a cleaning action also in the absence of the collapse of the bubbles by acoustic waves.

[0043] Surfactants can contribute to the formation of bubbles and / or their stabilization, being for example chosen from foaming surfactants such as polyoxyalkylenated alkyl(amido) ether carboxylic acid anionic surfactants, anionic surfactants other than the aforementioned polyoxyalkylenated alkyl(amido) ether carboxylic acids, non-ionic surfactants, amphoteric and zwitterionic surfactants, and mixtures thereof and / or are chosen from compounds conventionally present in makeup remover compositions such as alkylpolysaccharides, polyethylene glycol of fatty alcohols, oils, and mixtures thereof. Any surfactant capable of generating micelles in the medium may be used. Acoustic waves

[0044] The acoustic waves can be generated by a single transducer, or alternatively by at least two transducers.

[0045] When the acoustic waves are emitted by several transducers, these are for example all directed towards the area to be treated, being for example of longitudinal axes converging towards it. It is possible to use, if necessary, two transducers arranged towards each other to treat a lock of hair introduced between them. This can make it possible to treat two opposite sides of the lock simultaneously. It is also possible to have transducers arranged side by side to treat a larger area, with or without an overlap of the areas treated by each.

[0046] Each transducer comprises one or more electroactive elements for transforming an electric current into mechanical vibrations, this or these electroactive elements being for example based on piezoelectric materials, as detailed below.

[0047] This or these electroactive elements can be coupled to a sonotrode which can be mechanically resonated by the electroactive element(s) and serves to define a surface for emitting acoustic waves towards the target surface or volume.

[0048] The acoustic waves can be generated permanently as soon as the treatment device is put into operation, or alternatively can only be generated when certain operating conditions are met, such as for example the presence of the composition in contact with the sonotrode and / or the presence of the device in contact with the area to be treated and / or if the device detects that the area contains dirt.

[0049] Alternatively, the acoustic waves can be generated only when the quantity of composition in contact with the surface to be cleaned is sufficient, or when certain conditions for generating cavitation are detected, such as contact between the emission surface of the sonotrode and the surface to be treated, a minimum height of composition, a temperature of composition or transducer within a given range, or other.

[0050] Acoustic waves can be generated by a pulsed electrical signal, or continuous, preferably a pulsed electrical signal.

[0051] They can be generated by a sinusoidal electrical signal or by a signal of more complex shape, for example frequency modulation or amplitude modulation. The acoustic waves are preferably emitted at a single frequency, which can allow them to be focused more precisely in a given area, but alternatively they can be emitted at several different frequencies.

[0052] Said frequency is preferably between 30 and 100 kHz, in particular between 30 and 45 kHz. Such a frequency allows both the generation and satisfactory collapse of the bubbles in the composition, as well as a collapse alone of any bubbles already present in the medium in the composition. The acoustic waves are for example generated by a transducer with a nominal frequency of approximately 34 kHz.

[0053] The nominal frequency may vary around 34kHz, for example 34 kHz + / - 5 kHz.

[0054] The electrical signal exciting the transducer(s) may be pulsed with a pulse duration preferably between 0.01s and 0.1s, better still between 0.02 and 0.08s.

[0055] The duty cycle, when the signal is pulsed, is preferably between 20% and 100%, better between 50% and 70%, for example approximately equal to 50% + / - 10%, 58.3% + 1- 10% or 66.7% + / - 10%.

[0056] Variations relative to a nominal value may arise, where appropriate, from the rise in temperature of the transducer, for example through the excitation of the ceramics constituting a piezoelectric electroactive element. These variations may also come from the rise in temperature of the liquid where the cavitation is generated.

[0057] The method may include a step of detecting the presence of the cosmetic composition in contact with the sonotrode, and conditioning the operation of the transducer on this detection.

[0058] This avoids the emission of acoustic waves in the absence of composition or when the device is not in a situation of treating keratin materials.

[0059] Preferably, the acoustic waves are emitted without the emission surface of the sonotrode coming into contact with the area to be treated. The distance between the transducer and the surface to be treated is for example between 1 and 30 mm, more particularly between 3 and 5 mm, which makes it possible to limit the acoustic energy emitted in the keratin materials, and to promote the cavitation of the bubbles in the composition.

[0060] “The distance between the transducer and the surface to be treated” should be understood as the distance between the emission surface of the sonotrode and the surface to be treated.

[0061] A composition can be circulated continuously in contact with the sonotrode, with continuous operation of the transducer(s), or alternatively pulsed operation of the transducer(s). The composition can also be supplied in a pulsed manner. Advantageously, a supply of a zone subjected to acoustic waves which is discontinuous, with for example a period of feeding the zone while the acoustic waves are not generated, then a period where the composition present in the zone is subjected to the acoustic waves without being renewed during this exposure. This can prevent the bubbles present in the composition before entering said zone from being repelled by the acoustic waves present in it.

[0062] It is thus possible to control the supply of composition to the treatment zone to the operation of the transducer(s) for producing the acoustic waves or vice versa, and to have a pulsed operation of the transducer(s) and / or the supply of composition. In other words, it is possible to carry out a supply of composition offset in time relative to the period of emission of the acoustic waves in the composition supply zone.

[0063] The propagation of acoustic waves is facilitated by the presence of liquid in the composition. The gas / liquid mass ratio within the composition can thus benefit from not being too high, and the composition can advantageously contain a thickener, as detailed below, or any other compound making it possible to increase the temporal stability of the bubbles.

[0064] Preferably, an activation voltage is delivered to the transducer making it possible to obtain a peak acoustic intensity I greater than or equal to 5 W / cm2. The peak intensity I is preferably between 5 and 10 W / cm2, better still between 6 and 7.5 W / cm2.

[0065] The surface to be treated is preferably subjected to the acoustic waves for a duration of between 0.2 and 10s, better between 2 and 5s, for example 4s + / - 0.4s. Such an “effective” duration of application of the acoustic waves allows effective cleaning while limiting a possible feeling of discomfort for the user. The duration may correspond to the time measured between the start of excitation of the transducer to treat a given surface and the end of excitation of the latter in the treatment of said surface. This time may be applied in a single time or in several times added together.

[0066] The surface to be treated is for example subjected to acoustic waves for a duration equal to 4 s + / - 0.4 s, the peak acoustic intensity is equal to 6.2 + / - 0.6 W / cm2, and: - the composition has a total concentration of surfactant(s) of between 0.8 and 1.5%, the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 50 and 67%, or, - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, and • the pulse duration Ton is between 0.025 and 0.080 s and the duty cycle is between 50 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 52 and 65%.

[0067] As a variant, the surface is for example subjected to acoustic waves for a duration equal to 4 s + / - 0.4 s, the peak acoustic intensity is equal to 6.8 W / cm2 + / - 0.7 W / cm2 and: - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, and • the pulse duration Ton is between 0.027 and 0.080 s and the duty cycle is between 50 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 52 and 67%,

[0068] or - the composition has a total concentration of surfactant(s) equal to 0.8% + / -0.1%, and • the pulse duration Ton is between 0.030 and 0.080 s and the duty cycle is between 50 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 52 and 67%,

[0069] or - the composition has a total concentration of surfactant(s) equal to 1.0% + / -0.1%, and • the pulse duration Ton is between 0.035 and 0.080 s and the duty cycle is between 50 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 52.5 and 67%,

[0070] or - the composition has a total concentration of surfactant(s) equal to 1.2% + / -0.1%, and • the pulse duration Ton is between 0.035 and 0.080 s and the duty cycle is between 51.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 54 and 67%,

[0071] or - the composition has a total concentration of surfactant(s) equal to 1.5% + / -0.1%, and • the pulse duration Ton is between 0.038 and 0.080 s and the duty cycle is between 54 and 67%, or • the Ton pulse duration is between 0.020 and 0.080 s and the duty cycle is between 57.5 and 67%.

[0072] As a variant, the surface to be treated is for example subjected to acoustic waves for a duration equal to 4 s + / - 0.4 s, the peak acoustic intensity is equal to 7.2 W / cm2 + / - 0.7 W / cm2, and: - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 50 and 67%,

[0073] or - the composition has a total concentration of surfactant(s) equal to 0.8% + / -0.1%, and • the pulse duration Ton is between 0.030 and 0.070 s and the duty cycle is between 51 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 52.5 and 67%,

[0074] or - the composition has a total concentration of surfactant(s) equal to 1.0% + / -0.1%, and • the pulse duration Ton is between 0.030 and 0.070 s and the duty cycle is between 52.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 55 and 67%,

[0075] or - the composition has a total concentration of surfactant(s) equal to 1.2% + / -0.1%, and • the pulse duration Ton is between 0.025 and 0.070 s and the duty cycle is between 56 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 59 and 67%,

[0076] or - the composition has a total concentration of surfactant(s) equal to 1.5% + / -0.1%, the pulse duration Ton is between 0.028 and 0.045 s and the duty cycle is between 59 and 63%.

[0077] As a variant, the surface to be treated is for example subjected to acoustic waves for a duration equal to 3 s + / - 0.3 s, the peak acoustic intensity is equal to 6.2 W / cm2 + / - 0.6 W / cm2, and: - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, and • the pulse duration Ton is between 0.070 and 0.080 s and the duty cycle is between 54 and 60.5%, or • the pulse duration Ton is between 0.055 and 0.078 s and the duty cycle is between 56 and 62%,

[0078] or - the composition has a total concentration of surfactant(s) equal to 0.8% + / -0.1%, and • the pulse duration Ton is between 0.040 and 0.080 s and the duty cycle is between 51 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 56 and 67%,

[0079] or - the composition has a total concentration of surfactant(s) equal to 1.0% + / -0.1%, and • the pulse duration Ton is between 0.035 and 0.080 s and the duty cycle is between 51.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 54 and 67%,

[0080] or - the composition has a total concentration of surfactant(s) equal to 1.2% + / -0.1%, and • the pulse duration Ton is between 0.040 and 0.080 s and the duty cycle is between 51.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 54 and 67%,

[0081] or - the composition has a total concentration of surfactant(s) equal to 1.5% + / -0.1%, and • the pulse duration Ton is between 0.035 and 0.080 s and the duty cycle is between 55 and 67%, or • the Ton pulse duration is between 0.020 and 0.080 s and the duty cycle is between 57 and 67%.

[0082] As a variant, the surface to be treated is for example subjected to acoustic waves for a duration equal to 3 s + / - 0.3 s, the peak acoustic intensity is equal to 6.8 W / cm2 0.7 W / cm2, and: - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, and • the pulse duration Ton is between 0.020 and 0.065 s and the duty cycle is between 56 and 67%, or • the pulse duration Ton is between 0.035 and 0.075 s and the duty cycle is between 53.5 and 64%,

[0083] or - the composition has a total concentration of surfactant(s) equal to 0.8% + / -0.1%, and • the pulse duration Ton is between 0.030 and 0.072 s and the duty cycle is between 53 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 55 and 64.5%,

[0084] or - the composition has a total concentration of surfactant(s) equal to 1.0% + / -0.1%, and • the pulse duration Ton is between 0.032 and 0.070 s and the duty cycle is between 54 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 56 and 64.5%,

[0085] or - the composition has a total concentration of surfactant(s) equal to 1.2% + / -0.1%, and • the pulse duration Ton is between 0.032 and 0.070 s and the duty cycle is between 55.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 58 and 64%,

[0086] or - the composition has a total concentration of surfactant(s) equal to 1.5% + / -0.1%, and • the pulse duration Ton is between 0.025 and 0.063 s and the duty cycle is between 61.5 and 67%, or • the Ton pulse duration is between 0.030 and 0.058 s and the duty cycle is between 60 and 67%.

[0087] As a variant, the surface to be treated is for example subjected to acoustic waves for a duration equal to 3 s + / - 0.3 s, the peak acoustic intensity is equal to 7.2 W / cm2 + / - 0.7 W / cm2, and: - the composition has a total concentration of surfactant(s) equal to 0.5% + / -0.1%, and • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 57 and 65%, or • the pulse duration Ton is between 0.030 and 0.065 s and the duty cycle is between 55 and 67%,

[0088] or - the composition has a total concentration of surfactant(s) equal to 0.8% + / -0.1%, and • the pulse duration Ton is between 0.020 and 0.080 s and the duty cycle is between 58 and 67%, or • the pulse duration Ton is between 0.020 and 0.068 s and the duty cycle is between 55 and 67%,

[0089] or - the composition has a total concentration of surfactant(s) equal to 1.0% + / -0.1%, and • the pulse duration Ton is between 0.020 and 0.0725 s and the duty cycle is between 58.5 and 67%, or • the pulse duration Ton is between 0.020 and 0.0575 s and the duty cycle is between 56 and 67%,

[0090] or - the composition has a total concentration of surfactant(s) equal to 1.2% + / -0.1%, and • the pulse duration Ton is between 0.020 and 0.060 s and the duty cycle is between 61 and 67%, or • the Ton pulse duration is between 0.020 and 0.046 s and the duty cycle is between 58.5 and 67%. Gas bubbles.

[0091] Bubbles may be generated during pressure drops in the composition and the lowering of the vapor pressure which generates the release of gases. Preferably, the bubbles are generated by acoustic waves, but alternatively, they are additionally generated by a specific generator.

[0092] The gas bubbles can be air, CO2, oxygen, hydrogen, nitrogen, among other possibilities, as well as a mixture of these gases.

[0093] All the bubbles may be bubbles of the same gas or alternatively the composition may comprise bubbles of a first gas and bubbles of a second gas, different from the first.

[0094] The gas may come from a decomposition of the composition, for example by fermentation, or be extracted from it, or alternatively be introduced into the composition.

[0095] The diameter of the bubbles can range from 50 nm to 700 pm, better from 500 nm to 50 pm. The size here refers to the average size D50 in number at half of the population.

[0096] The dimensionless factor is equal to the ratio d / Rmax, where d is the distance from the geometric center of the bubble to the surface to be cleaned when the expansion of the bubble is maximum, and Rmax is the maximum expansion diameter of the bubble, is preferably less than 3.5, better less than 1.1 in order to have maximum efficiency, as detailed in the publication “Mechanisms of single bubble cleaning”, F. Reuter, Ul-trasonics Sonochemistry 29(2016) 550-562.

[0097] The density of the medium formed by the cosmetic composition with the gas bubbles, exposed to the acoustic waves, can be between 0.1 and 1 g / cm3, better between 0.5 g and 1 g / cm3 (at 20°C and at atmospheric pressure).

[0098] A small bubble size can facilitate their penetration into reliefs and / or follicles of the skin, such as hair follicles, crevices, wrinkles, scars, interstices or folds, and thus exert an effective cleansing action within them. It may thus be advantageous for the bubbles to have a size less than or equal to 300 microns, better still 200 microns, for example a size of 100 microns or less. The bubbles can then penetrate into the follicles before being activated by the acoustic waves. Additional bubble generation

[0099] Preferably, the bubbles are generated only by acoustic waves during the cavitation phenomenon, obtained in particular thanks to a minimum level of Isata and the other aforementioned parameters, as described above.

[0100] Alternatively, additional bubbles may be generated within the composition. These additional bubbles may be generated by any suitable means, for example by mechanical, physical, chemical or electrochemical means. The bubbles may in particular be generated by a depression in the liquid which makes it possible to lower the vapor pressure and generate the formation of gas in the form of bubbles.

[0101] The generation of additional bubbles can be prior, simultaneous or cyclical with respect to the emission of acoustic waves.

[0102] As examples of techniques that can be implemented to generate the bubbles in the invention, include among others the techniques:

[0103] - decompression of liquids using nozzles for example, decompression which may be preceded by pressurization,

[0104] - creation of a turbulent flow, in particular using rotating blades, of a turbine, an ejector, a Venturi, a swirling gas or liquid flow, a static or rotating porous body, including a rotating disk, a generator as described in the publication Performance of a new micro-bubble generator with a spherical body in a flowing water tube by M.Sadatomi Experimental Thermal and Fluid Science 29 (2005) 615-623, a Venturi tube and a vortex, a Venturi as implemented by MEC Co. (lona Shower), or shear forces,

[0105] - creating a laminar flow through small openings, with foca lization or co-focusing of the flow of a porous membrane using an oscillator porous membrane fluidics as described for example in the article Fluidic os-cillator-mediated microbubble generation to provide cost effective mass transfer and mixing efficiency to the wastewater treatment plants Environ Res. 2015 Feb; 137:32-9, of an emulsification microchannel as described in the article Mono-dispersed microbubble formation using microchannel technique; AIChE Journal, 50 (2004), pp. 3227-3233, these bubble creation techniques by laminar flow through small openings being preferred to the previous ones due to the stability of the bubbles produced.

[0106] - energy supply,

[0107] light, for example by irradiation of microfluidic channels coated with nanoporous gold, as described in Progress in Biomedical Optics and Imaging Proceedings of SPIE Volume 9705, 2016 Article number 97050D, Photothermal generation of microbubbles on plasmonic nanostructures inside microfluidic channels (Conference paper), by laser irradiation, for example as described in An Experimental study on microbubble generation by laser induced breakdown in water; The review of Laser Engineering (Suppl.) (2008), pp. 1273-1275 (2), by laser irradiation on carbon nanotubes, as described in the article Producing single microbubbles with control size using microfiber Advance in Bioscience and Bio-technology, 2 (2011), pp.385-390, by a tapered optical fiber, by a near-infrared plasmonic absorber, as described in the publication Size-controllable micro-bubble generation using a nanoimprinted plasmonic nanopillar array absorber in the near-infrared region. ; Applied Physics Letters. 108. 2016, .

[0108] acoustic, for example by ultrasound as described in the article Ultrasonics Sono-chemistry Volume 29, 1 March 2016, pp. 604-611, Influence of sonication conditions on the efficiency of ultrasonic cleaning with flowing micrometer-sized air bubbles, sonic activation of microbubbles, ultrasound in the presence of nucleation sites, as described in application WO2016 / 055883,

[0109] electrical, for example by a coaxial electrodynamic atomization process as described in the publication Preparation of microbubble suspensions by coaxial elec-trohydrodynamic atomization, Medical Engineering and Physics, 29(2007), pp749-754, by electrolysis, electro flotation, by a micro electrolytic generator as described in the publication Micro-fabricated electrolytic micro-bubblers, International Journal of Multiphase Flow, 31 (2005), pp. 706-722, by electrostatic spraying as described in the publication Microbubble generation for environmental and industrial separations, Separation and Purification Technology, 11 (1997), pp. 221-232, by electrical heating of carbon nanotubes as described in the publication Microbubble generation with micro-watt power using carbon nanotubes heating elements; Proceedings of the 7th IEEE International Conference on Nano- technology, August 2-5, 2007, Hong Kong (2007) or by micro plasma, as described in the article Journal of Physics D; Applied Physics Volume 47 Issue 35, 3 September 2014, Article number 355203; Microbubble generation by microplasma in water.

[0110] The additional bubbles may be generated continuously, as soon as the device is put into operation. Alternatively, the bubbles are generated intermittently, for example only when the composition is dispensed, or in periods at a predefined frequency so as to allow them time to disperse. A certain quantity of bubbles may be present in the composition before the device is put into operation. Alternatively, the bubbles may be generated before or without the device being put into operation.

[0111] The intensity of bubble production can be constant or variable, and where appropriate adjustable by the user or automatically by the device depending on the desired result or at least one operating parameter.

[0112] The bubbles may be generated by any of the techniques mentioned above, in particular by injecting a pressurized gas into the composition, for example by means of a pump or a compressed gas reservoir, by electrolysis of the cosmetic composition, by stirring the composition, sucking a gas into the composition, or vaporizing a liquefied gas mixed with the composition or dissolved in the composition. The bubbles may come from the reaction of two liquids or of a liquid and at least one solid in the form of, for example, powder, granules, tablets, or any other form.

[0113] The flow of liquid containing the bubbles, in the case where bubbles are generated upstream, can range from 0.01 mL / s to 10 mL / s. Abrasion

[0114] The method may comprise abrasion of the keratin materials using abrasive particles and / or by a part of the device in contact with the keratin materials.

[0115] This abrasion can be carried out by a device other than the one which emits the acoustic waves, by the device itself, or by a specific part mounted on the device, such as a grid, blade, scraper or any other suitable accessory.

[0116] The part allowing the abrasion to be carried out is for example put in place to carry out the abrasion, then removed at the time of treatment by the bubbles and acoustic waves, being for example interchangeable with a part of the device used for treatment by the acoustic waves and bubbles.

[0117] The part for carrying out the abrasion may still be present during the treatment of the bubbles and acoustic waves, as will be described below. This part may then have the form of a grid, among other possibilities.

[0118] Abrasion may be carried out prior to exposure of the composition cosmetic and bubbles to acoustic waves, or alternatively concomitantly. When abrasion is prior, it can be carried out by any means, in particular by mechanical or chemical action.

[0119] The abrasion of keratin materials can be caused not only by the shock wave phenomenon which follows the exposure of the bubbles to acoustic waves, but also at least in part by the action of abrasive particles contacting the surface to be treated, these abrasive particles being for example present in the composition or on a surface of the device coming into contact with the external keratin materials.

[0120] The abrasive particles present in the cosmetic composition may be insoluble in the medium of the composition or, alternatively, soluble in it, and preferably then generate a gas during their dissolution, a gas which will then be used to generate all or part of the bubbles subjected to the acoustic waves. The abrasive particles may be formed by a precipitation reaction linked to a chemical reaction.

[0121] The abrasive particles may be chosen from abrasive powders of materials having a hardness on the Mohs scale greater than or equal to 3, for example powders of alumina, silica, aluminosilicates, carbonates, or a material coated with a silica, an alumina or an aluminosilicate.

[0122] It may also be powdered fruit kernels, in particular apricot kernels, wood cellulose, for example crushed bamboo stem, crushed coconut shell, oyster shell, shell, sand, silicas, or a synthetic material such as polyamide, or mixed particles combining organic and inorganic compounds, and particles coated with the above compounds.

[0123] The abrasive particles may have a size between 0.1 and 500 microns, in particular between 0.1 and 50 microns for the treatment of hair, between 10 and 300 microns for the treatment of the scalp or facial skin.

[0124] The solid particles used to exert an abrasive action may have a flattened, spherical, elongated, polyhedral or irregular shape.

[0125] Abrasive particles may be added during processing to the device or liquid.

[0126] The device may contain a chamber dedicated to the controlled storage and distribution of abrasive particles or a compound allowing the formation by reaction or precipitation of these particles. Recycling

[0127] Preferably, the cosmetic composition is sent into contact with the keratin materials so as to be at least partially recovered for recycling.

[0128] The composition that is recovered can be filtered to remove solid debris or its particulate phase, before being returned to the surface to be cleaned.

[0129] Preferably, the composition is recovered by suction or by absorption, for example using a porous support or a suction system, in particular using a pump as detailed below. Application of the cosmetic composition

[0130] Generally speaking, the composition can in itself, by its formulation, already contribute to the removal of the impurities that one wishes to remove by the action of the bubbles subjected to the acoustic waves. The action of the bubbles subjected to the acoustic waves can accelerate this process or improve it. Thus, the association of the wave generated by the collapse of the bubbles in combination with the action of the combination can have, by synergy, an effect greater than that of the waves alone or that of the composition alone.

[0131] The cosmetic composition can be applied initially, with bubbles already present within it or not, then exposed in a second stage, after its application to the keratin materials, to acoustic waves to generate new bubbles, and cause shock waves following the collapse of all the bubbles.

[0132] For example, the user first applies a cosmetic composition, for example in the form of foam, to the area to be cleaned, for example by spraying it onto said area, and then brings a treatment device into contact with the composition, to subject it to acoustic waves.

[0133] The cosmetic composition can also be applied differently, and in particular continuously, that is to say that a circulation of the composition is established in contact with the keratin materials to be treated, this circulation being for example in a closed or open circuit.

[0134] When circulation is carried out in a closed circuit, the composition is recycled at least partially. An additional quantity of composition can be introduced continuously or intermittently into the circuit to compensate for losses.

[0135] At any time, the circulation can be stopped to promote prolonged static contact of the composition on the surface to be cleaned. The circulation can be done without the presence of bubbles allowing initial contact with the keratin material to prepare it for cleaning, for example.

[0136] In an open circuit, the composition is not recycled for the implementation of the process, and for example is eliminated to a collection tank or directly with the wastewater.

[0137] The circulation of the composition in the device is carried out for example with a flow rate of between 0.01 mL per second and 15 mL per second.

[0138] The bubbles can be formed while the cosmetic composition is already in contact with the keratin materials, under the action of acoustic waves and / or with the aid of a bubble generator specific to the device, operating for example by electrolysis. Selection of treated areas

[0139] The method can be carried out on all or part of the skin of the face, scalp or body, to clean it.

[0140] The treated area may in particular be an area of ​​keratin materials coated with a makeup product such as a foundation, a lipstick, a blush, a mascara, an eyeliner, a powder, an emulsion, an oil or a sunscreen product, among others, and the treatment may aim to eliminate this product.

[0141] The method may be carried out by moving a handpiece along the area to be treated, so as to treat the entire area covered by the makeup product or other substance that it is desired to remove.

[0142] The method can also be implemented to treat an area of ​​skin not coated with a makeup product, in order to clean it thoroughly, and remove or treat exogenous or endogenous impurities or defects, for example dead skin cells, traces of sebum or sweat, dandruff, bacteria, traces of pollution, blackheads, pigmented spots, light scars or acne scars. The method can be implemented to treat the scalp. The method can also be implemented on the top of the nails to remove nail polish.

[0143] The method may include a step of detecting the areas to be treated, certain parameters such as the acoustic intensity being able to be adjusted automatically according to the cleaning or treatment needs for the detected areas.

[0144] The device may comprise an optical detector for detecting the presence of a compound to be removed from the surface of the skin, for example a foundation or a sunscreen. The detector comprises, for example, a light emitter and a sensor of the reflected signal, which can be analyzed to detect the presence of the compound to be removed, and possibly determine the quantity present. For example, the emission power of the acoustic waves is automatically adjusted according to the intensity absorbed at a predefined wavelength.

[0145] Detection can also be carried out in the liquid coming from the treated area, in particular in the case of recycling thereof; a high turpidity of this liquid can be representative of the presence of a high quantity of particles removed from the surface. Thus, the intensity of the acoustic waves can be automatically adjusted according to the transparency of the liquid, the intensity being for example automatically increased when the liquid is cloudy, because many particles are removed by the treatment, and decreased when it becomes clear again, a sign that the treatment is no longer removing much.

[0146] The method can also be implemented to clean the hair, in particular with a view to at least partially removing a previously carried out coloring.

[0147] The method can also be implemented on the hair to remove excess sebum or other substances such as biological agents, pathogenic or not, from dandruff. Additional procedures

[0148] The method according to the invention may be preceded or followed by a cosmetic process such as makeup or massage.

[0149] For example, the skin, hair or eyelashes are made up, then the make-up is removed after a certain period of time (for example less than 24 hours) using the cleaning method according to the invention.

[0150] In another example, the skin is cleansed by implementing the method according to the invention, then a treatment is carried out on the cleansed area (for example just after or less than two hours after), for example a massage and / or the application of a care composition. Treatment kit

[0151] The invention also relates to a treatment kit for implementing the method according to the invention, as defined above.

[0152] This kit includes: - the cosmetic composition in which the bubbles are generated, - a device for exposing the bubbles to acoustic waves in the vicinity of the surface to be treated.

[0153] The composition may or may not be packaged with the device in the same packaging.

[0154] The composition may be obtained by diluting a concentrated composition. This dilution may be achieved by a liquid or solid composition, for example in tablets, bars, chips, powder, preferably a liquid composition, containing all or part of the constituents of the concentrated composition (in different proportions).

[0155] Where appropriate, the composition is contained in a container arranged to be mounted on the device, this container constituting for example a cartridge arranged to be fixed in whole or in part in a corresponding housing of the device, or to be connected to the device by a suitable connection such as a pipe. Other compounds

[0156] The composition may generally comprise any compound conventionally included in the formulation of compositions for cleaning and / or caring for human keratin materials, compatible with the generation of sufficiently high bubbles stable before the application of acoustic waves. Device for treating keratin materials

[0157] The invention also relates, according to another of its aspects, to a device for treating keratin materials in contact with a cosmetic composition containing at least one surfactant, in particular for implementing the method according to the first aspect of the invention described above, the device comprising at least one ultrasonic transducer arranged to emit acoustic waves in the vicinity of said materials to be treated, the transducer being powered by a current generator delivering to the transducer an electrical signal, pulsed or not.

[0158] The device may in particular comprise at least one ultrasonic transducer arranged to emit acoustic waves into a fluid present in the vicinity of said materials to be cleaned, the transducer being powered by a current generator delivering to it an electrical signal, pulsed or not, this electrical signal preferably having: - at least one frequency component between 20 kHz and 100 kHz, - a Ton / Toff duty cycle when the signal is pulsed between 20 and 100%, and / or - a pulse duration Ton when the signal is pulsed between 0.01 and 1s,

[0159] the acoustic intensity Isata on the surface of said keratin materials preferably being at least 0.1 W / cm2.

[0160] The characteristics of the method described above apply to the device in combination or independently of each other. Hair treatment device

[0161] The invention also relates, according to another of its aspects, to a device for treating human hair, in particular with a view to cleaning the hair, removing previous coloring, and / or bleaching it, this device being intended to treat the hair while it is in contact with a fluid, in particular an aqueous fluid, in particular a cosmetic composition, within which bubbles of a gas are present and / or generated, this device comprising: - at least one transducer having an emission surface for emitting acoustic waves in the vicinity of the hair to be treated, in order to generate a collapse of said bubbles, - at least one guiding and / or combing member arranged to guide the hair in its movement near and / or in contact with said emission surface.

[0162] The acoustic waves emitted by the emission surface of the transducer make it possible in particular to cause, by cavitation, the formation and collapse of bubbles within the fluid, and thus to generate a mechanical effect on the hair which promotes the detachment of exogenous or endogenous elements, and in particular causes them to discolor.

[0163] The cosmetic composition may contain very small amounts of surfactants, for example less than 5% of surfactants. This low level of surfactants may prove particularly favorable to the action of acoustic waves on the fluid and the bubbles present therein.

[0164] Among the undesirable impurities that may be present on the hair, we can distinguish exogenous impurities such as environmental pollution, dust, microorganisms, etc., and endogenous impurities or defects such as excess sebum, dead cells, etc.

[0165] The cosmetic composition may, or may not, have bubbles already present within it before the application of the acoustic waves.

[0166] The bubbles generated and / or present may also contribute to the release of chemical species contributing to the cleaning and / or bleaching of hair, such as free radicals.

[0167] The device according to the invention is particularly suitable for bleaching hair, in particular hair which has already undergone a coloring treatment, and which has a color which is not its natural color.

[0168] The device can be used to bleach a lock of hair only on the outside, so as to give a highlighting effect to the hair.

[0169] The device can also be used to bleach specific areas of the hair, in particular specific areas of a lock of hair, using intermittent emission of ultrasound.

[0170] The device, and in particular at least part of the guiding and / or combing member, can heat and / or diffuse light, this making it possible, for example, to activate certain compounds present in the fluid, in particular in the cosmetic composition. Device with pump and tanks

[0171] The device according to the invention preferably comprises a system for distributing and / or recovering the composition, comprising at least one composition reservoir and at least one pump, in particular electrically driven, arranged to circulate the composition in a fluid circuit between the reservoir and the keratin materials to be treated.

[0172] Thus, the invention also relates to a device for treating keratin materials in contact with a fluid, in particular a cosmetic composition, the device comprising: - a handpiece comprising a treatment head to be placed in contact with the keratin materials to be treated, - carried by the handpiece, at least one ultrasonic transducer arranged to emit acoustic waves in the vicinity of said materials to be treated and generate bubbles in the fluid, the bubbles preferably being generated by the transducer exclusively, without an additional bubble generator, and - a fluid distribution and / or recovery system, comprising at least one fluid reservoir and at least one pump arranged to circulate the fluid in a fluid circuit between the reservoir(s) and the keratin materials to be treated.

[0173] Preferably, the device is for non-therapeutic purposes, in particular for the topical application of a cosmetic composition.

[0174] The device according to the invention makes it possible to effectively treat both exogenous impurities and endogenous impurities or defects, while meeting certain environmental requirements and safety standards in force.

[0175] The fluid distribution and / or recovery system allows for savings in water and chemical compounds.

[0176] Preferably, the handpiece comprises a handle, which may be arranged non-coaxial with the treatment head. The handle may at least partially contain the fluid delivery and / or recovery system. Alternatively, the device may comprise a base station connected to the handpiece by a cord, the pump and / or the reservoir(s) being arranged in the base station. Pump

[0177] The pump can be driven by any type, in particular manually or electrically, preferably electrically.

[0178] The pump can be of various types. The pump is for example a volumetric or centrifugal pump, in particular peristaltic, diaphragm, piston, or a combination of several types.

[0179] The pump can be powered by direct or alternating current. Preferably, the supply voltage of the pump is less than 50V, for example being powered at a voltage ranging from 5 to 12V.

[0180] The pump is preferably compatible with liquids of various types, in particular aqueous, oily, mixed liquids, liquids containing particles or suspended charges, or even polymers.

[0181] When the pump is driven by an electric motor, the motor is for example direct current with or without brushes, in particular with permanent magnets. These magnets can be based on ferrites or rare earths.

[0182] The motor has, for example, when used to drive the pump, a rotation speed of between 1 and 10,000 rpm.

[0183] Such a speed can be fixed, or variable, the motor being for example controlled by a speed variator, for example pulse width modulation, resistance (passive or active) acting on the supply current or voltage, or by a frequency variation variator.

[0184] The motor can be single-phase or three-phase.

[0185] The pump mechanism can be driven directly by the motor or in a reduced manner.

[0186] When the drive is manual, the device may include a handle that is operated by the user to operate the pump.

[0187] Preferably, the pump is configured to provide a fluid flow rate between 0.01 mL and 15 mL per second.

[0188] The pump may or may not be removable. The pump may generate negative and / or positive pressure on the fluid to allow the fluid to circulate and come into contact with the skin. The pump may also be used for internal cleaning of all or part of the device.

[0189] The pump may contain a filter in one or more parts. The pump may be mechanically or electrically isolated in the device, for example to be removed from the device for cleaning. Tanks

[0190] The device may comprise one or more fluid reservoirs, this fluid preferably being the aforementioned cosmetic composition.

[0191] The reservoir(s) may be arranged in the handpiece, in particular in its handle, or at least partially outside the handpiece, for example in a base station connected to the handpiece.

[0192] Alternatively, the reservoir(s) may be arranged to project relative to the handpiece.

[0193] The device may comprise several separate reservoirs, for example a reservoir of fluid to be distributed to the area to be treated and a reservoir for receiving the used fluid which has been at least partially recovered following the treatment.

[0194] The reservoir(s) may or may not be removable. The reservoir(s) are, for example, disposable and may be replaced when there is no more fluid, or when the recovered fluid must be evacuated.

[0195] It is also possible to provide reservoirs of varying capacities depending on the treatment to be carried out on the keratin materials, the device being able to be configured to allow the user to put in place the reservoir of his choice, chosen from several with different respective capacities.

[0196] The tank(s) can be cleaned, filled or emptied, for example manually from the outside after having been removed from the device beforehand, or even directly while they are still present in the device, for example using the pump and fluid circuit.

[0197] In this case, the device comprises, for example, a selector which makes it possible to change the circulation of the fluid from a first configuration where the circulation takes place between the reservoirs and the treatment zone, and a second configuration used for purging and / or filling the reservoir.

[0198] The reservoir(s) may comprise several compartments, in particular several compartments integrated into the same body and separated by a wall, or several communicating compartments, for example connected by a tube. The reservoir(s) may comprise a compartment containing the composition to be distributed to the areas to be treated, and a compartment collecting the composition used, for example for recycling. The two compartments may communicate, for example through a filter.

[0199] The reservoir(s) may also comprise several compartments in which different compositions may be stored. These compositions may be mixed at the time of use and some may be solid and / or in the form of rapidly soluble powders.

[0200] For example, a reservoir may contain a first compartment comprising a solid composition, for example in the form of powder or crystals, and a second compartment comprising a fluid composition, the two compartments being able to communicate during use so that the fluid composition solubilizes the solid composition.

[0201] The first compartment may also comprise a mixture of a suspended solid composition and a liquid in which the solid composition is insoluble, the fluid composition of the second compartment solubilizing the mixture during use of the device.

[0202] The reservoir(s) may include one or more filters to filter impurities from the collected fluid before redistributing it to the area to be treated. The reservoir may also include a vent.

[0203] The reservoir(s) may comprise a device for heating or cooling the fluid, in particular an electrical resistor.

[0204] The reservoir(s) are preferably compatible with one or more liquids of various natures, in particular different types of composition, miscible or not, and cleaning liquids.

[0205] The reservoir(s) are preferably at least partially transparent, which allows the user to visually see their filling level and / or the level of cleanliness of the fluids they contain.

[0206] The tank(s) may be deformable, or made of rigid material, in particular glass or plastic.; A tank may include a removable part, and thus be of adjustable volume according to what is desired. The tank(s) can be fitted with valves allowing them to be disconnected from the housing receiving them without loss of fluid.

[0207] The reservoir(s) may be in the form of cartridges, generally cylindrical or otherwise shaped, or flexible pouches.

[0208] The capacity of the reservoir(s) is for example between 1 ml and 200 ml, better between 1 and 50 ml. Fluidic circuit

[0209] The fluid circuit preferably comprises a plurality of conduits, which are connected in a suitable manner to achieve the desired fluid circulation, for example with end-to-end or parallel connections, being connected together by suitable connections.

[0210] The fluid circuit connects together the different parts of the device concerned with the circulation of the fluid, such as the treatment head, the pump(s) and the fluid reservoir(s), as well as the filter(s) or other purification or disinfection systems, or even additional bubble generation.

[0211] The fluid circuit may comprise one or more modifiable bypasses or valves, for example one or more manual or electrically controlled valves.

[0212] The pump may contain a one or more part filter.

[0213] The fluid circuit may include a water intake allowing it to be charged with water. and / or clean it from an external network.

[0214] The fluid circuit can also be modular with removable sections, for example sections that are added when cleaning the circuit. For example, a section can be added comprising a cleaning powder that dissolves at least in part when a liquid passes through the circuit. The section that is thus added can be used only for cleaning, and removed afterwards, or left in place until the next cleaning, then being replaced by a new one.

[0215] The reservoir(s) and the fluid circuit allowing the circulation of the fluid may belong to the same assembly forming a refill, capable of being handled as a single unit for its placement on the device and removal from the latter; refilling with product is then made easier. Such a refill may, if necessary, have a mechanical interface with the pump or other drive mechanism, allowing, when actuated, a circulation of product to be established from the cartridge to the treatment zone.

[0216] The refill assembly may be arranged to be fixed, for example by snap-fastening or otherwise, in the handpiece, for example in the same housing as that containing another component of the device, for example an electric generator. Fluid treatment and purification unit

[0217] The device according to the invention may comprise a system for at least partial recycling of the fluid, comprising a conduit opening near the area to be treated and communicating with a suction system, in particular a suction pump.

[0218] The suction system is preferably arranged to send the recovered fluid to a treatment and purification unit, the fluid being for example returned at the outlet of the treatment and purification unit to a reservoir in order to be distributed again to the area to be treated.

[0219] The treatment and purification unit can be arranged inside the handpiece, in particular in its handle, or be at least partially moved outside, for example in a base station connected to the handpiece by a cord.

[0220] The treatment and purification unit preferably comprises one or more removable parts. It can be washable and reusable in whole or in part.

[0221] The treatment and purification unit may comprise a filtration system capable of at least partially filtering any fluid circulating in the device, in particular the cosmetic composition used for the treatment, or any additional liquid used to clean the device.

[0222] Preferably, the filtration system comprises at least one filter, in particular a filter having a pore size less than or equal to 50 microns.

[0223] The filter may be a non-woven material, with or without pleats. The filter may comprise one or more elements chosen from a fabric, a porous material, activated carbon particles, sand, silica, a porous polymer, a natural or synthetic foam.

[0224] The filter can have a high capture power, in particular a nano-filter.

[0225] The filtration system may also include a pre-filter, which may be positioned in downstream or upstream of the suction system.

[0226] The filtration system may include a filter efficiency sensor, configured to indicate to the user whether a filter needs to be changed or cleaned, for example by changing color when the filtration system is saturated. Such a sensor may also be a pressure sensor capable of detecting filter clogging.

[0227] Where appropriate, the fluid circuit of the device is arranged to circulate the fluid counter-currently during a cleaning phase, in order to unclog the filter.

[0228] The treatment and purification unit may comprise several elements distributed in different parts of the device; for example, this unit may comprise a filtration system present in at least one conduit of the fluid circuit, and a disinfection system or one intended to carry out another treatment, arranged in a compartment of a tank.

[0229] The treatment and purification unit may comprise a separator of the type centrifugal, designed to extract, using the centrifugal force imparted to the fluid by making it swirl, the impurities from the used fluid which has been in contact with the keratinous materials, towards a collection area.

[0230] The treatment and purification unit may include a disinfection unit which destroys any living organisms present in the recycled fluid, such as bacteria, viruses, spores or other pathogenic or non-pathogenic biological agents.

[0231] The disinfection unit may comprise for this purpose any suitable biocidal means, preferably at least one UV lamp and / or an oxidant or ozone generator, in particular a UVC LED type lamp. Ultrasonic transducer

[0232] The device comprises an ultrasonic transducer.

[0233] As described above, the transducer comprises one or more electroactive elements for transforming an electric current into mechanical vibrations, this or these electroactive elements being able to be advantageously coupled to a sonotrode put into mechanical resonance and defining a surface for emitting acoustic waves towards the target surface or volume.

[0234] These acoustic waves can cause rapid pressure changes that can lead to bubble cavitation; the acoustic waves can, as described above, lead to the formation of bubbles and their collapse, or to the collapse of bubbles already present in the medium.

[0235] The longitudinal axis of the transducer may designate that of the sonotrode. The latter may be symmetrical in revolution around its longitudinal axis, or of another shape. It may be an axis of symmetry of the transducer, the latter being for example symmetrical in revolution around said axis or of another shape.

[0236] The longitudinal axis may also correspond to the direction in which the electroactive element(s) have the greatest amplitude of movement when excited.

[0237] The sonotrode may be made of metal, preferably titanium, which enhances the effects of bubble cavitation. The sonotrode may also be at least partly made of aluminum, stainless steel, or ceramic. The sonotrode may comprise several metals or alloys.

[0238] The transducer may comprise at least one piezoelectric material, in particular lead zirconate titanoate (PZT)

[0239] Preferably, the sonotrode is made of a corrosion-resistant material allowing it to be at least partially immersed in the composition.

[0240] The acoustic wave emission surface of the sonotrode may be covered with a protective layer to protect the sonotrode from possible degradation due to cavitation of bubbles in contact with it, and / or from corrosion.

[0241] The invention is not limited to a particular shape or a given size for the sonotrode. However, a size compatible with the portable nature of the handpiece is preferred, in order to allow it to be handled with one hand by the user.

[0242] The sonotrode may have an emission surface in contact with the composition which ranges, for example, from the surface of a circle with a diameter of 5 mm to a circle with a diameter of 100 mm, better still from the surface of a circle with a diameter of 5 mm to that of a circle with a diameter of 50 mm, even better still from the surface of a circle with a diameter of 5 mm to that of a circle with a diameter of 40 mm.

[0243] The sonotrode can be given any shape adapted to that of the surface to be treated, for example round, oval, or polygonal, in particular square or triangular.

[0244] The emission surface of the transducer may be removable relative to the transducer, for example so that it can be replaced by the user, in particular to offer different solutions for guiding and / or combing the hair and / or adapting to the type of relief of the guiding and / or combing member.

[0245] Preferably, the transducer as a whole or the sonotrode are removable, that is to say they can be easily detached by the user from the device, preferably without using a tool. This facilitates cleaning and allows, if desired, to interchange several transducers or sonotrodes according to the use and the desired energy parameters, for example by choosing the type of transducer or sonotrode best suited to generating acoustic waves at a given frequency.

[0246] By interchanging the transducers, the acoustic intensity can be varied as required.

[0247] Thus, the device can be used for a wide range of applications, depending on the transducer and / or sonotrode chosen. The choice of transducer and / or sonotrode may depend on various parameters, for example the nature of the treatment sought, the type of keratin materials to be treated, or the frequency of use of the device (daily, weekly, etc.).

[0248] The device may further comprise a mechanical element with adjustable opening, such as a diaphragm, arranged in front of the sonotrode so as to limit the surface area of ​​emission of the ultrasonic waves. The diaphragm may be adjustable by the user to adjust the power of the treatment and / or the extent of the treatment area.

[0249] The transducer and / or the sonotrode may comprise means of attachment to the rest of the device by snap-fastening, by screwing, by bayonet, by friction, magnetic, by clamping, in particular using at least one clamping screw, a clamp, a magnet, or by any other suitable means.

[0250] The transducer can move longitudinally and / or transversely, in particular to move closer to or further away from the hair to be treated. It can rotate around its longitudinal axis and / or vibrate.

[0251] The sonotrode can have any shape at the level of the surface of emission of the acoustic waves.

[0252] The device may comprise means for driving the transducer or the sonotrode, configured to generate an oscillating, vibrating and / or rotating movement thereof, independently of the generated acoustic waves.

[0253] The transducer can be powered continuously or alternatively, in particular independently of the other elements of the device such as the pump.

[0254] The transducer or the associated sonotrode may comprise a conduit preferably opening onto the emission surface, connected to the fluid circuit so that they are crossed by the fluid circulating in the device. Such circulation makes it possible to cool the transducer.

[0255] The device may comprise several transducers, in particular two transducers. This makes it possible, for example, to increase the effectiveness of the treatment by the device. Reliefs at the level of the emission surface

[0256] The surface for emitting acoustic waves towards the liquid medium may include reliefs where the bubbles may originate at different levels along the longitudinal axis of the transducer. In particular, these reliefs may offer nucleation sites at their top and at their base.

[0257] Thus, the invention also relates, according to another of its aspects, to a device for treating keratin materials in contact with a fluid, in particular a cosmetic composition, the device comprising: - At least one ultrasonic transducer having a surface for emitting acoustic waves into said fluid to generate bubbles therein having a mechanical action when they collapse on said keratin materials, the emission surface having reliefs where the bubbles can originate at different levels along the longitudinal axis of the transducer.

[0258] Reliefs can allow for more homogeneous bubble production. In comparison, a smooth emission surface tends to generate nucleation sites randomly distributed over the surface, and non-optimal bubble production. These reliefs can also promote bubble collapse, because the differences in levels along the longitudinal axis allow for the generation of relatively large cavitation zones, not limited to a single plane.

[0259] The reliefs can also make it possible to generate a turbulent flow in the fluid, which can participate in the production of bubbles, in particular when the fluid contains a surfactant.

[0260] The reliefs can be formed in various ways.

[0261] The reliefs can be produced by any process allowing a predefined shape to be created by removing material, for example by machining, chemical attack, electroerosion, laser engraving, by molding or additive synthesis, or by inlaying foreign bodies.

[0262] The reliefs can be monolithic with the sonotrode, being for example produced by machining the latter.

[0263] The reliefs can also be formed on at least one insert, which is fixed to the sonotrode.

[0264] This insert receives at least part of the vibrations of the sonotrode and transmits them to the liquid medium; it defines at least part of the surface for emitting acoustic waves in the fluid.

[0265] The insert may be made of the same material as the sonotrode, or of a different material, in particular a harder one. Preferably, the insert which includes the reliefs is made of a rigid material, in order to transmit the acoustic waves without too much attenuation. It may be metallic, made of an alloy or made of ceramic.

[0266] The use of an added part to define the emission surface of the acoustic waves in the liquid medium can facilitate its replacement in the event of wear of the emission surface, the collapse of the bubbles being likely to produce wear of the latter.

[0267] The insert may be fixed by any means to the sonotrode, in particular held thereon by a removable fastener. For example, the insert is screwed onto the sonotrode. When the fastener does not have to be removable, the insert may be welded or otherwise fixed to the sonotrode.

[0268] The sonotrode may be made of a material harder than aluminum, for example titanium or stainless steel.

[0269] The reliefs can thus be made of titanium with the sonotrode, for example by machining the end face of the latter.

[0270] The insert may be made of a material harder than aluminum, for example titanium or stainless steel. In this case, the sonotrode may be made of titanium or a material less hard than it, for example aluminum, because it is not directly exposed to cavitation.

[0271] The reliefs preferably have a predefined shape, but alternatively, they can be created randomly, and have, for example, at least one parameter which is random, for example their size or their location. Thus, all or part of the reliefs can have a distribution on the emission surface and / or a random size.

[0272] The reliefs can be arranged in a regular arrangement, in other words a structured shape, for example in a regular network in two dimensions (the third being the longitudinal axis of the sonotrode).

[0273] The reliefs may be identical; for example, the emission surface comprises the same elementary pattern which is repeated in two directions perpendicular to each other.

[0274] This pattern may have a prismatic shape, for example pyramidal, or other, for example hemispherical, cylindrical, hemicylindrical, ogival, etc.

[0275] The reliefs may be in the form of ribs or grooves, where appropriate, which may be parallel to each other or not, rectilinear or circular, or in the form of a grid, or have a random distribution. The grooves may be formed by scratching the surface for example. The reliefs may be formed by subjecting the surface to shot blasting or sandblasting, which may lead to a random distribution and / or relief shapes.

[0276] The emission surface may have reliefs having a height, measured parallel to the longitudinal axis of the sonotrode, of between 0.001 mm and 50 mm, better still 0.01 mm and 30 mm, even better still between 0.1 and 1 mm.

[0277] In front view, that is to say when the emission surface is observed in the longitudinal axis of the sonotrode, the largest dimension of the reliefs can be between 0.001 mm and 100 mm, better between 0.1 and 1 mm.

[0278] The free end of the reliefs may be rounded or flat, in order to avoid injury to the skin in the event of contact with it.

[0279] The surface for emitting acoustic waves may thus comprise at least one relief having a non-regular pyramidal, truncated cone, cylindrical, hemispherical or prismatic shape. The emitting surface may comprise a regular network of four-sided pyramidal reliefs.

[0280] The surface for emitting the acoustic waves may comprise at least one relief having at least two facets oriented differently towards the area to be treated.

[0281] The reliefs may, if necessary, have another additional function, for example guiding and / or combing hair in the treatment area.

[0282] When the reliefs are formed by the presence of successive patterns in one or two directions, the size of the patterns and the distance between consecutive patterns are for example chosen such that the pattern density is between 1 and 106 patterns / cm2.

[0283] When the patterns have vertices, all of the vertices belong, for example, to the same plane or to the same spherical, cylindrical, parabolic or ellipsoidal surface.

[0284] In addition to the reliefs of the emission surface which contribute to improving the production of bubbles, the emission surface may have reliefs which pursue another purpose, for example to exert an action of retaining the fluid or cleaning the area to be treated. These are, for example, reliefs made of a flexible material, for example bristles, in particular flocking bristles.

[0285] The emission surface of the transducer may have one or more reliefs, such as teeth, and / or natural and / or synthetic bristles, and / or engravings, and / or micro-protrusions, and / or metal spikes, for example to comb and / or help guide the hair, upstream or downstream of the treatment area, or even at the level of the latter.

[0286] The emission surface may have the same type of reliefs as the guide and / or combing member, or alternatively different reliefs.

[0287] The emission surface may also have one or more reliefs when the guide and / or combing member does not have any. As a variant, the guide and / or combing member may have one or more reliefs when the emission surface does not have any. Additional vibrations

[0288] The invention also relates to a device for treating keratin materials in contact with a fluid, in particular a cosmetic composition, the device comprising: - At least one ultrasonic transducer having a surface for emitting acoustic waves in said fluid to generate bubbles therein having a mechanical action when they collapse on said keratin materials, - a vibrator for subjecting at least part of the emission surface to additional vibrations, of a frequency lower than that of the acoustic waves.

[0289] It is possible to subject at least part of the emission surface to additional vibrations, of a frequency lower than that of the acoustic waves, for example vibrations of a frequency lower than or equal to 1500 Hz, even better lower than or equal to 150 Hz, or even 50 Hz.

[0290] The entire device may be subjected to said additional vibrations. Alternatively, only a part is, for example only the transducer, the sonotrode or a part thereof, or the treatment head.

[0291] The device may comprise a vibrator for this purpose, for example a vibrator comprising a motor driving a rotating unbalance.

[0292] The emission surface is thus subjected by the vibrator, for example, to additional transverse and / or longitudinal and / or angular vibrations, preferably longitudinal. The direction of the vibrations can be adjusted, for example, by adjusting the orientation of the axis of rotation of the unbalance relative to the longitudinal axis of the transducer.

[0293] These additional vibrations can promote greater homogeneity of the cavitation and can improve the wetting of the acoustic wave emission surface by the fluid.

[0294] The additional vibrations can be emitted simultaneously with the emission of the acoustic waves or alternatively; the device can be arranged to allow, where appropriate, the generation of these vibrations to be activated or not, for example by starting or not starting the motor driving the unbalance, or even adjusting its rotation speed.

[0295] It may be particularly advantageous to subject the emission surface to these additional vibrations in the presence of reliefs as defined above on the emission surface, the combination of reliefs and vibrations making it possible to more easily obtain additional turbulence in the fluid in contact with the materials to be treated, which improves, as described above, the production and collapse of bubbles within the fluid. Treatment head

[0296] The device may comprise a treatment head in contact with the keratin materials to be treated, the head preferably being arranged to distribute the fluid to the area to be treated via at least one fluid outlet, and / or to recover at least partially the fluid used from the area to be treated via at least one fluid return inlet.

[0297] The hair treatment device may comprise a treatment head in which the fluid circulates, in particular the cosmetic composition, the transducer and the guide and / or combing member extending at least partially in this treatment head.

[0298] Preferably, the transducer extends at least partially into the treatment head. In particular, it may be housed entirely therein.

[0299] The outlet and / or the inlet are for example connected to the aforementioned fluid circuit. In particular, the fluid circuit may be arranged relative to the head so as to distribute and / or partially recover the fluid in front of and / or behind the emission surface of the sonotrode, for example through at least one orifice on the emission surface.

[0300] The treatment head may comprise a heating element such as an electrical resistor, for heating the composition for example, and / or a light source arranged to illuminate the treatment area during use and / or activate certain constituents of the fluid in which the cavitation occurs.

[0301] The treatment head may comprise at least one filter, which is used for example to filter the composition which is recycled, this filter being for example arranged on the return path of the fluid.

[0302] The treatment head may comprise a porous material and / or one capable of releasing or diffusing a fluid, in particular an open-cell foam, preferably carried by a removable support, in particular in the form of a frame.

[0303] The treatment head may comprise distribution orifices such as slots, closed at rest, opening under the pressure of the upstream composition, and have elasticity allowing an increase in volume during filling and a distribution of the fluid continuing after the end of the filling action.

[0304] The treatment head may comprise a chamber for storing a sufficient quantity of fluid to enable the cleaning of keratin materials and the contact of the bubbles with the surface to be cleaned.

[0305] The treatment head may comprise several compartments, independent or communicating with each other.

[0306] The treatment head may comprise parts made of flexible and / or deformable material, in particular elastically deformable, in particular for the parts in contact with the keratin materials to be treated.

[0307] The treatment head can be of various shapes, depending on the intended use for the device.

[0308] The treatment head may comprise one or more removable parts, easily detachable by the user of the device, preferably without using a tool.

[0309] This makes it easier to clean between uses.

[0310] The removable part(s) of the treatment head may be attached to the rest of the device via any suitable attachment means, in particular a ball joint, spring, or a piston. The treatment head is preferably movable; in examples it may tilt or be rotated through more than 180°, 270° or 360° around at least one axis.

[0311] The transducer is preferably arranged relative to the treatment head so as to keep the acoustic wave emission surface of the sonotrode away from the surface of the keratin materials to be treated.

[0312] Where appropriate, the transducer is movable relative to a fixed part of the device, for example driven by a rotational or back-and-forth movement, as described elsewhere.

[0313] Cavitation thus occurs in the front part of the head, in a space provided between the emission surface of the sonotrode and the surface of the keratin materials to be treated.

[0314] Thus, the fluid can be made to circulate in this space, which is possibly adjustable.

[0315] This circulation can be carried out continuously, as mentioned above, or intermittently. It is also possible to fill said space with the fluid while the handpiece is in place, then generate the acoustic waves within the fluid filling this space. Guiding and / or combing organ

[0316] In the case of hair treatment, the device according to the invention may comprise at least one guiding and / or combing member arranged to guide the hair in its movement near and / or in contact with the emission surface of the transducer.

[0317] The guiding and / or combing member ensures that the hair is at an appropriate distance from the surface emitting the acoustic waves during the treatment, and thus maintains the effectiveness of the treatment.

[0318] The guiding and / or combing member can keep the hair at a predefined distance from the emission surface, for example by acting as a spacer.

[0319] The guiding and / or combing member can retain the hair in the vicinity of the emission surface, by opposing the movement away of the hair in a direction parallel to the longitudinal axis of the transducer or in a direction both perpendicular to the longitudinal axis of the transducer and the longitudinal direction of the hair; the guiding and combing member does not oppose the movement of the hair in front of the emission surface of the acoustic waves.

[0320] The guiding and / or combing member may not prevent the hair from coming into contact with the acoustic wave emission surface, in the absence of a spacer placed in front of it.

[0321] The guiding and / or combing member also allows for good division of a lock of hair and for obtaining a homogeneous thickness of hair in the treatment area, which allows for homogeneous treatment of the lock.

[0322] In examples, the hair is combed by said guiding and / or combing member, which can make it possible to spread it in front of the emission surface in order to facilitate the action of the bubbles.

[0323] The guiding and / or combing member may be arranged to guide the hair laterally, for example by having stops between which the hair is engaged.

[0324] The guiding and / or combing member may comprise at least one lateral hair guiding surface, making it possible to hold the hair during treatment.

[0325] At least one lateral guide surface, better two lateral guide surfaces, of the guide and / or combing member, can be perpendicular to the surface for emitting the acoustic waves.

[0326] The guiding and / or combing member may be made at least partially from a metallic material and / or a polymer, for example a rigid plastic material.

[0327] The guiding and / or combing member may have, on its surface, a treatment which makes it possible to reflect the acoustic wave, which makes it possible to amplify the treatment of the hair.

[0328] The guide and / or combing member may be removably or non-removably attached to the device.

[0329] At least a portion of the guiding and / or combing member can vibrate, and / or rotate, and / or move longitudinally and / or transversely.

[0330] The guiding and / or combing member may be in the form of a single-piece element or of several elements assembled together or on the device to perform the desired guiding and / or combing function(s).

[0331] The guide and / or combing member may comprise at least one guide portion intended to come into contact with the hair and at least one support portion which serves to maintain the guide portion in the desired configuration during treatment.

[0332] Guide portion of the guide and / or combing member

[0333] The guide portion may be fixed or movable relative to the rest of the device, and in particular it can be movable relative to the transducer, for example in order to move it closer to or further away from the surface emitting the acoustic waves. It is thus possible to control relatively precisely the distance between the emitting surface and the surface of the hair to be treated, which makes it possible to improve the action of the bubbles in the vicinity of the surface of the hair, while avoiding, if desired, direct contact of the emitting surface with the hair.

[0334] When movable, the guide portion may be rotatable or axially movable, for example rotating about its own longitudinal axis and / or moving along its own longitudinal axis and / or moving along an axis perpendicular to its own longitudinal axis.

[0335] The guide portion may have a guide surface extending at least partially opposite the emission surface and / or on either side thereof, in particular defining with the emission surface a treatment space.

[0336] The distance between the emission surface and this guide surface may be between 0.1 mm and 50 mm, in particular between 0.1 mm and 30 mm, and where appropriate adjustable by the user, in particular to adapt the device to the thickness of hair to be treated.

[0337] The guide surface may be of a width greater than or equal to that of the emission surface, for example being of a width between 1 mm and 180 mm, the emission surface being for example of a width between 1 and 150 mm. By "width" is meant here the dimension in a direction perpendicular to the direction of travel of the hair, and perpendicular to the longitudinal axis of the transducer.

[0338] The guide portion may be hollow to define a cavity for guiding the hair to be treated, the cavity defining a treatment space. This cavity may be open at two opposite ends and the hair may extend between these two ends. The guide portion may be moved along a strand of hair to be treated, the hair moving in the cavity between its ends.

[0339] The cavity may be opened laterally between its ends to allow the introduction of hair. Alternatively, the hair is introduced through one end before exiting through the other.

[0340] The cavity may be formed by a guide portion of generally tubular shape, in particular cylindrical, in particular axially split tubular.

[0341] The inner surface of the cavity may have reliefs which contribute to the combing and / or retention of the hair. These reliefs may be in the form of ridges for example, or have another shape as detailed below.

[0342] The guide portion may be, at least in part, permeable to acoustic waves and the transducer placed outside the guide portion, such that the acoustic waves emitted by the emission surface of the transducer reach the fluid, in particular the cosmetic composition, present in the cavity with the hair, generate bubbles and / or cause them to collapse.

[0343] The guide portion may also form all or part of the transducer, in particular all or part of a sonotrode thereof, while defining the aforementioned cavity, the emission surface being in this case formed by at least part of the surface of the cavity.

[0344] The cavity may have a constant or variable internal diameter. By "internal diameter" we mean that of the largest circle inscribed in the cross-section of the cavity.

[0345] The guide portion may be located between at least two transducers, for example two diametrically opposed transducers.

[0346] For example, the guide portion defines a hair guide cavity which is located between two transducers; this cavity is for example open at its axial ends and between them to define a hair insertion slot.

[0347] The guide portion may be in contact with the two transducers, forming for example all or part of the sonotrode thereof, and / or be permeable to the acoustic waves emitted by them.

[0348] The guide portion may comprise at least two parts which are movable relative to each other, for example in the form of jaws, between a spaced-apart configuration for introducing the hair between them, and a close-together configuration for holding the hair in the treatment space.

[0349] The guide portion comprises, for example, a proximal part, closest to the transducer, and a distal part, furthest away.

[0350] The proximal portion may be permeable to acoustic waves, and may overlap at least partially, in front view, the emission surface. By "front view" is meant the view in a direction generally perpendicular to the emission surface.

[0351] The proximal part of the guide portion may, in order to be permeable to acoustic waves, include holes, in particular be made in the form of a grid, or even be made of a specific material permeable to acoustic waves.

[0352] The distance between the proximal and distal parts can vary between 0 mm in the close configuration and 100 mm in the spaced configuration, in particular between 0 mm in the close configuration and 50 mm in the spaced configuration.

[0353] The proximal portion may be fixed relative to the transducer or movable relative to it.

[0354] The distal portion may be fixed relative to the transducer or movable relative to the latter, given that at least one of the portions is movable relative to the other.

[0355] At least one of the distal and proximal portions may be biased towards a rest position by at least one elastic return means, such as a spring.

[0356] In particular, the proximal and distal portions may be biased by one or more resilient biasing means into the close configuration, or alternatively, into the spaced configuration, and preferably further configured to allow the user to exert a force opposite the biasing action, in order to move the proximal and distal portions in the opposite direction when necessary, for example when inserting hair between said portions, when extracting hair, and / or during treatment.

[0357] The guide member may comprise a single guide portion or several guide portions.

[0358] Support portion of the guide and / or combing member

[0359] The guide and / or combing member may comprise at least one support portion which ensures its maintenance during use of the device.

[0360] The support portion may comprise a mechanism allowing translation of the guide and / or combing member along the longitudinal axis of the transducer, in particular a mechanism including one or more springs allowing the support portion to be returned to a rest position. This rest position corresponds, for example, to the hair being pressed against the guide and / or combing member and / or against the emission surface during treatment.

[0361] The support portion may be movable relative to the transducer in order to free up space opposite the emission surface, and allow, for example, the introduction of hair into the treatment area.

[0362] The portion may be movable in translation or rotation or according to a kinematic combining at least one translation and one rotation.

[0363] For example, the support portion may pivot relative to the transducer about an axis of rotation perpendicular to the longitudinal axis of the transducer.

[0364] If the guide and / or combing member comprises a two-part support portion, the latter can pivot simultaneously in order to tilt the member. guiding and / or combing on the side of the transducer. Reliefs on the guide and / or combing member

[0365] The guide and / or combing member may comprise at least one guide and / or combing relief on its surface.

[0366] The guide and / or combing relief may extend continuously, or non-continuously, over the guide and / or combing member. The guide and / or combing relief may be absent from certain parts of the guide and / or combing member.

[0367] The guiding and / or combing member may comprise, on its surface, at least one guiding and / or combing macro-relief capable of engaging in the hair, in particular at least one tooth, and / or a natural or synthetic bristle.

[0368] The guide and / or combing member may comprise on its surface, in particular on the surface of at least one tooth, at least one micro-relief, in particular an engraving and / or a micro-protrusion, resulting in particular from a sandblasting type treatment of the guide and / or combing member.

[0369] These guiding and / or combing reliefs make it possible to guide and / or comb and / or hold and / or put under tension the hair during treatment.

[0370] At least one guiding and / or combing relief, in particular at least one tooth and / or at least one bristle, may extend into a space located opposite the emission surface.

[0371] The guide and / or combing member may comprise at least one guide and / or combing relief, in particular a tooth and / or a bristle, extending outside a space located opposite the emission surface. The guide and / or combing member may in particular comprise at least one row of teeth, or bristles, extending outside a space located opposite the emission surface.

[0372] The guide and / or combing member may comprise at least one row of teeth, or bristles, between which the hair can engage.

[0373] The distance between the longitudinal axes of the teeth, or bristles, of a row may be between 0.1 mm and 10 mm.

[0374] The teeth, or bristles, of a single row may all be aligned. Alternatively, the teeth, or bristles, of a single row may be arranged in a staggered pattern.

[0375] At least one tooth may be conical, circular or elliptical in shape. Alternatively, at least one tooth may be pyramidal in shape with a square or rectangular base, or cylindrical in shape.

[0376] At least one tooth, or one bristle, in particular at least one tooth of a row of teeth, or one bristle of a row of bristles respectively, may have a height of between 0.1 mm and 50 mm, in particular between 0.5 mm and 20 mm.

[0377] At least part of the guiding and / or combing member may be in the form of a twisted core brush type brush comprising natural bristles and / or synthetic.

[0378] At least a portion of the guiding and / or combing member, for example a portion of the guiding and / or combing member in the form of a twisted core brush, can rotate about its longitudinal axis, under the emission surface as the hair passes between the guiding and / or combing member and the emission surface.

[0379] The guide and / or combing member may have a single type of guide and / or combing reliefs, or alternatively several different types of guide and / or combing reliefs.

[0380] Circulation of fluid in the guide and / or combing member

[0381] At least a portion of the guide and / or combing member may be hollow, in order to allow the circulation of fluid, in particular the cosmetic composition, inside.

[0382] At least part of the guiding and / or combing member may be traversed by a conduit capable of bringing the fluid, in particular the cosmetic composition, into the treatment space for example.

[0383] In its hollow part, the guiding and / or combing member can accommodate an anhydrous composition, such as a composition of a carbonate, in particular sodium or calcium, and an acid, citric for example, which can dissolve as the fluid circulates, in particular the cosmetic composition, and which can release gas bubbles.

[0384] The guiding and / or combing member may comprise at least one orifice allowing the fluid, in particular the cosmetic composition, circulating inside, to exit, this orifice opening for example at the treatment space. The orifice opens for example in the direction of the emission surface, for example it is located opposite the emission surface.

[0385] Such an orifice can allow the release of the fluid, in particular the cosmetic composition, directly into contact with the hair, which can contribute to the effectiveness of the treatment.

[0386] The guiding and / or combing member may comprise between 1 and 100,000 or more orifices, allowing the fluid, in particular the cosmetic composition, circulating inside to exit. These orifices may be produced by machining, for example, or may be created by the intrinsic structure of the material used.

[0387] The guiding and / or combing member can thus be made at least in part from a porous material, having a very large number of pores allowing the fluid, in particular the cosmetic composition, circulating inside to escape.

[0388] The guide and / or combing member may comprise at least one orifice allowing the recovery of the fluid, in particular the cosmetic composition, after treatment, for example by suction of the fluid, in particular of the cosmetic composition.

[0389] The guide and / or combing member may be covered, at least in part, with a fabric or non-woven sleeve, the sleeve may be made at least in part of a polymer, so as not to damage the hair fibers. The sleeve may be made so as to allow the fluid, in particular the cosmetic composition, to pass through the orifices of the guide and / or combing member, and thus allow better diffusion of the fluid, in particular the cosmetic composition.

[0390] The sleeve may be at least partially soluble, in particular entirely soluble, as the fluid, in particular the cosmetic composition, exits through the orifices, and may thus participate in the treatment of the hair thanks to the compounds released during its dissolution. For example, the sleeve may be made at least in part from polyvinyl alcohol (PVA) fibers or any other soluble polymer which may be in the form of a fabric, a sheet or even in a non-woven form.

[0391] At least one guide and / or combing relief may be hollow, in order to allow the circulation of the fluid, in particular of the cosmetic composition, inside.

[0392] At least one guide and / or combing relief may comprise at least one orifice allowing the fluid, in particular the cosmetic composition, circulating inside to exit. Tip

[0393] The treatment head may comprise a tip, preferably removable, in contact with the keratin materials to be treated.

[0394] The tip, when removable, is for example chosen according to the use, for example by selecting the type, size, hardness and / or shape best suited to the morphology of the area to be cleaned. Grid

[0395] The invention also relates to a device for cleaning human keratin materials in contact with a cosmetic composition within which bubbles of a gas are present and / or generated, the device comprising: - at least one ultrasonic transducer arranged to emit acoustic waves in the vicinity of said materials to be cleaned, - a grid, preferably non-absorbent, in particular at least partially made of a non-absorbent material, defining a contact surface with said materials to be cleaned, having at least one opening, preferably at least two openings, through which the waves emitted by the transducer can propagate towards the materials to be cleaned.

[0396] Thanks to the grid, it is possible to control more precisely the distance between the transducer and the surface of said keratin materials, which makes it possible to improve the action of the bubbles in the vicinity of the surface of the keratin materials, while avoiding direct contact of the transducer with these keratin materials.

[0397] The grid is preferably non-absorbent, i.e. it is not porous.

[0398] The grid may in particular not have the capacity to soak up water when immersed in water, and retain for example less than 10% of water, better still less than 5% of its water weight.

[0399] The grid can in particular be made from a solid material, therefore different from foam, fabric or felt.

[0400] The contact surface of the device with the keratin materials can be defined by a non-absorbent surface of the grid.

[0401] The region of the grid defining the openings thereof may be defined by a non-absorbent portion of the grid.

[0402] The grid is preferably removable, that is to say it can be easily detached by the user of the device, preferably without using a tool. This facilitates cleaning and allows it to be replaced between uses, or, if desired, to interchange several grids depending on the use, for example by choosing the type of grid best suited to the morphology of the area to be cleaned.

[0403] The contact surface defined by the grid may be substantially flat, for example in order to maintain a substantially constant distance between the transducer and the keratin materials to be cleaned located opposite the acoustic wave emission surface.

[0404] Alternatively, the grid may define a contact surface adapted to the morphology of the area to be cleaned, for example of a curved shape.

[0405] The grid may further have, where appropriate, an adjustable effective diameter. The device may comprise a variable aperture mechanical element such as a diaphragm, arranged in front of or behind the grid, so as to adjust the accessible diameter of the opening(s). For example, the device comprises a diaphragm centered on the longitudinal axis of the transducer.

[0406] Some or all of the openings of the grid can be closed in whole or in part in a controlled manner. This makes it possible, depending on the area to be treated, and in particular for more sensitive areas such as those located in the vicinity of the eyes, to limit the surface area and intensity of treatment, if desired. The device may comprise a shutter movable between a position of non-occultation of one or more openings of the grid and a occultation position where the opening(s) are occulted at least partially, or even totally. This shutter is for example adjusted manually by the user as required.

[0407] Preferably, the grid has a thickness of between 0.1 and 10 mm, better still between 0.5 and 5 mm. Thus, a minimum distance of at least this thickness is ensured between the transducer and the keratin materials, regardless of the position of the grid relative to the transducer.

[0408] The grid is preferably formed from a rigid or semi-rigid material, for example metal, or rigid plastic. The grid is for example made from a material chosen from a metal, in particular steel, stainless steel, an alloy, silicone, a polymer, in particular of the polyurethane (PU), polyethylene terephthalate (PET) or polythiophene (PT) type, or a combination of several of these elements.

[0409] The grid may not deform visibly to the naked eye during normal use, due to its rigidity. Alternatively, the grid may be deformable. For example, its diameter may be reduced by applying mechanical pressure to its contour.

[0410] The grid may comprise recesses, in particular extending along its thickness. The grid comprises, for example, deformable channels, the diameter of which may vary according to the pressure applied, extending for example in a non-longitudinal direction. Alternatively, the channels may be rigid in order to allow the passage of fluid even if pressure is applied to the grid.

[0411] The grid may still have reliefs or be flocked, or not.

[0412] The grid can be made with reliefs or in an intrinsically rough, in order to have a non-smooth contact surface with keratinous materials. Such a surface condition makes it possible to obtain a mechanical abrasive effect which can participate in cleaning when the device is moved over the area to be cleaned during use.

[0413] The device may comprise a grid drive element configured to generate an oscillating, vibrating and / or rotating movement of the grid to the keratin materials. For example, the device comprises a motor for driving the grid in movement, for example rotary, linear, eccentric or other, reciprocating or not. The device may comprise a vibrator, if necessary, to vibrate the grid. The amplitude of the movement may be fixed or adjustable.

[0414] The mechanical abrasive effect can thus be obtained automatically due to the movement imposed by the device on the grid, and the impurities cleaned more efficiently.

[0415] The grid can be made in different ways.

[0416] The grid may comprise a peripheral frame, which defines the outer contour of the grid in front view. This frame may be rigid, in particular more rigid than a central part of the grid, openwork.

[0417] The outline of the grid, in front view, may be circular, oval, polygonal or other in shape, and preferably the grid has a closed outline.

[0418] The opening(s) of the grid may be substantially the same size. The grid may comprise a plurality of openings arranged in a regular array, for example in rows or columns.

[0419] Alternatively, the opening(s) may be arranged concentrically.

[0420] The openings may have various shapes, in particular shapes in the form of portions of disc(s) or ring(s).

[0421] The grid may have a single opening, in particular of non-circular outline, for example in the form of a slot, a cross, a polygon, regular or not, or an oval. Preferably, the grid has at least two openings, in particular two openings having substantially the same size.

[0422] In the presence of a single opening, this may or may not be centered.

[0423] A grid having a fine mesh improves the maintenance of keratin surfaces at treat when using the device, which allows better control of a constant distance between said materials and the surface of emission of the acoustic waves, and thus of the phenomenon of cavitation.

[0424] An opening of the grid may have an area of ​​at least 1mm2. A smallest dimension of an opening of the grid, in front view, is for example at least 0.5mm.

[0425] Preferably, the grid has a ratio of the total surface area of ​​the openings relative to the contact surface area of ​​the grid with the keratin materials greater than or equal to 0.3, better still 0.5, even better still 0.8.

[0426] Such a ratio makes it possible to prevent keratin materials, in particular the skin, from rising up on contact with the transducer or from becoming deformed, while maintaining enough openings for the ultrasonic waves to reach the area to be treated or its vicinity over a sufficient extent with regard to the desired result. Leg spacer(s)

[0427] The invention also relates, according to another of its aspects, to a device for cleaning human keratin materials (K) in contact with a cosmetic composition (C) within which bubbles of a gas are present and / or generated, the device comprising: - at least one ultrasonic transducer having an emission surface for emitting acoustic waves in the vicinity of said materials to be cleaned, - a spacer contributing to maintaining the keratin materials at a predefined distance from the emission surface, this spacer advantageously comprising at least one leg extending axially over less than 360° around the axis of the transducer, in front of the emission surface.

[0428] By "forward" it is meant that the leg extends beyond the emission surface in the direction of the keratin materials to be treated.

[0429] The spacer may be in the form of a tip attached to the rest of the head of processing by means of a fixing part, or be monolithic with the body of the latter, for example.

[0430] The leg(s) may bear at one end directly against the keratin materials; this end may have a rounded head or a pad, in order to be able to slide more easily on the skin, for example. Alternatively, the leg(s) are connected to a part which extends for example transversely to the leg(s), for example in the form of a ring or grid, and which bears on the keratin materials.

[0431] The device may thus comprise a spacer without the aforementioned grid, a grid alone without a spacer with one or more legs, or even a spacer having at least one leg connected to the aforementioned grid.

[0432] Thus, the grid may be carried by a spacer comprising a grid support portion connected to at least one leg extending axially over less than 360° around the axis of the transducer, in front of the emission surface.

[0433] The leg(s) are preferably generally rectilinear, preferably parallel to the longitudinal axis of the transducer.

[0434] The leg(s) may extend towards the keratin materials in a direction substantially perpendicular to the surface of emission of the ultrasonic waves.

[0435] Alternatively, the leg(s) may extend away from the ultrasonic wave emission surface, which may improve the stability of the support of the device against keratin materials.

[0436] The spacer may comprise a distal portion intended to bear against the keratin materials, to which the leg(s) are connected.

[0437] This distal portion may extend at least partially opposite the surface for emitting the ultrasonic waves, or alternatively around it, when the device is observed along the longitudinal axis of the transducer.

[0438] This distal part has for example an annular shape, a bar, or a sliding pad, being for example provided with at least one opening, and being able to form the aforementioned grid.

[0439] Preferably, the spacer is laterally perforated. For example, the spacer comprises several legs, and the legs define openings between them. For example, the support legs are less than five. The angular intervals between the legs, around the longitudinal axis of the transducer, may be greater than the angular extent of each leg, measured around said longitudinal axis.

[0440] The leg(s) may also themselves have one or more openings.

[0441] Such openings allow the composition to circulate more easily in contact with the transducer when using the device, and possibly for the user to more easily visually check the position of the transducer and the presence of composition in contact with keratin materials, the openings forming windows allowing visual access to the space located in front of the transducer.

[0442] The openings also facilitate the possible passage of a gas or a light source, or temperature variations, in particular induced by a heat or cold production member of the device.

[0443] The fixing part of the tip which allows the leg(s) of the spacer to be fixed to the rest of the device, in particular to the treatment head, may be of any shape, in particular annular, and may include fixing means by snap-fastening, screwing, bayonet, friction, magnetic, clamping, in particular using at least one clamping screw or a clamp, or by any other suitable means.

[0444] Preferably, the position of the attachment part of the tip relative to the rest of the device is adjustable and can be adjusted so as to adjust the distance at rest between the emission surface of the transducer and the keratin materials. The device can in particular be made in such a way that this position can be adjusted by the user, for example by acting on an adjustment member such as a wheel or the like.

[0445] The spacer may have an adjustable height. For example, the tip may have several stackable sub-parts depending on the desired spacing.

[0446] The spacer may comprise an elastic return member, preferably at least one helical or blade spring, arranged to elastically bias the distal end of the spacer away from the surface emitting the acoustic waves and to enable the pressure of application of the spacer to the keratin materials to be controlled, which provides greater comfort in using the device.

[0447] The leg(s) are for example made telescopically, and the elastic return member acts to force them into deployment.

[0448] The legs can still be received in a sliding manner on the side of their proximal end in a guide, and the elastic return member opposes their insertion into this guide.

[0449] The grid, when fixed to the spacer, can thus be movable relative to the rest of the device, and returned by an elastic return means to an initial position, the elastic return means acting to apply the grid against the keratin materials to be treated.

[0450] Where appropriate, the recoil movement of the grid or of a movable part of the spacer, following the application of the device against the keratin materials to be treated, is limited by a stop against which the grid or the movable part comes to bear. The recoil movement of the grid or of this movable part can also be detected in order to automatically trigger the emission of acoustic waves when the device is applied against keratinous materials.

[0451] The grid and its support part which holds it in place relative to the emission surface may be formed of different materials, or not. Where appropriate, the support part and the grid are made of a single piece, for example are produced monolithically by injection molding, machining or 3D printing.

[0452] The leg(s) and / or the grid may also be current-conducting, for example to deliver an electric current into the composition and / or onto the materials to be treated.

[0453] Circulation of the composition in the spacer and / or the grid

[0454] The device according to the invention may comprise at least one supply conduit plugging near the keratin materials to be treated and allowing the composition to be distributed in contact with them, in particular at least one conduit extending along the leg(s), or in them, or more generally in the support part of the grid and / or in the latter.

[0455] When the spacer carries a grid at its end in contact with the keratin materials, the supply conduit may extend into the grid or the support part of the grid.

[0456] Such a device makes it possible to apply the cosmetic composition continuously, that is to say that a circulation of the composition is established in contact with the keratin materials to be treated, this circulation taking place for example in a closed or open circuit.

[0457] When the circulation is established in a closed circuit, the device may comprise at least one return conduit connected to a suction pump, making it possible to recover at least partially the composition in the vicinity of the keratin materials to be cleaned, in particular at least one conduit extending along the leg(s), and possibly in the grid or the support part of the grid.

[0458] Process for cleaning keratin materials with grid and / or spacer

[0459] The invention also relates to a method for cleaning human keratin materials in contact with a cosmetic composition within which bubbles of a gas are present and / or are generated, this method comprising the steps consisting of: - Bringing the grid or spacer of the device into contact with said keratin materials to be cleaned, - Subjecting gas bubbles to acoustic waves emitted by the ultrasonic transducer in the vicinity of the said materials to be cleaned, in particular in order to cause them to collapse and generate a mechanical shock on the surface to be cleaned to remove the dirt.

[0460] Acoustic waves can propagate through at least one or two openings in the grid.

[0461] The grid or spacer may be moved during treatment, for example intermittently, remaining stationary for a certain period of time, and then moved incrementally along the surface to be treated. The grid or spacer may still be moved continuously over the surface to be treated.

[0462] As mentioned above, the grid or spacer can be animated by a movement, in particular oscillatory, which combines with the movement imparted by the user.

[0463] The grid or spacer may, when moved in contact with the keratin materials to be cleaned, cause abrasion of the latter. Soft lip

[0464] The treatment head may comprise at least one flexible lip, which may also act as a spacer to maintain the aforementioned distance between the acoustic wave emission surface of the transducer and the surface to be treated.

[0465] The flexible lip, when the treatment head is applied to the keratin materials to be treated, can participate in the confinement of the fluid in the treatment area.

[0466] The lip may consist of sub-lips between which the fluid can be recovered.

[0467] The flexible lip is preferably made with a material comprising silicone, polyurethane (PU), natural or synthetic rubber, plastic, polyethylene terephthalate (PET) or polythiophene (PT), or a combination of several of these elements.

[0468] The flexible lip may be made with reliefs or from an intrinsically rough material, in order to have a non-smooth contact surface with the keratin materials. The flexible lip may thus contribute to the cleaning of the keratin materials thanks to a mechanical abrasive effect obtained when the device is moved over the area to be cleaned during use.

[0469] This flexible lip may also help to deliver, spread, collect and / or recycle the fluid. Battery

[0470] Preferably, the device comprises at least one battery, in particular a removable type battery. The battery can be used to power the entire device, or only a part, in particular the pump.

[0471] The battery may be of various types, for example Li-ion or NiMH, preferably of a type suitable for wet conditions or which can be immersed in a liquid at least partially.

[0472] The battery is preferably rechargeable, in particular by cable or induction, or when the device is placed on a support and / or a docking station allowing the battery recharge.

[0473] The battery is preferably selected to ensure, without having to be recharged, the power supply of the device during several consecutive treatments, or even several treatments and cleaning of the device. Other items

[0474] The device may include an electronic circuit controlling the operation of the transducer and possibly other elements of the device such as the electric pump.

[0475] The electronic circuit preferably comprises a control unit, for example a microcontroller, which can be carried by the handpiece and / or distributed between a possible base station and the handpiece, or present on the base station only.

[0476] The device may include several other sensors than those previously described, such as a contact sensor of the treatment head on the keratin materials to be treated, or a reservoir filling sensor, which can communicate data to the control unit.

[0477] The device may further comprise a human-machine interface communicating with the control unit. The human-machine interface may comprise a display screen and / or control buttons.

[0478] The interface may offer various functions and / or programs allowing, for example, certain operating parameters of the device to be adjusted, or certain information to be indicated to the user, such as the battery level, the time of use, the level of liquid in the tank, the level of fouling of the various washable elements (tank, filters, etc.), information specific to the user, or information relating to the safety and / or the conditions of use of the device.

[0479] The interface can also communicate via a wired or wireless connection, for example via Wifi or Bluetooth, with a terminal such as a mobile phone, in order for example to receive updates or send data related to the use of the device.

[0480] The interface may also include functionalities allowing a diagnosis of the keratin materials to be treated.

[0481] The device may include various switches, in particular a start and / or standby switch, a switch for selecting programs or certain parameters specific to ultrasonic waves, or for selecting the flow rate of the pump.

[0482] The device may also include one or more LED-type light sources, which may be used to illuminate the area to be treated or act as indicators, for example notifying the user of the need to change, fill or empty the tank, or to clean the filtration system.

[0483] As described above, the device may comprise a base station connected to the handpiece, which may be a handpiece charging and / or storage station. Bubble generator

[0484] Preferably, as described above, the bubbles are generated only by the acoustic waves during the cavitation phenomenon, obtained thanks to a minimum level of the Isata parameter and the other aforementioned parameters.

[0485] Thus, preferably, the device does not include a bubble generator.

[0486] Alternatively, the device may comprise a bubble generator for generating additional bubbles within the fluid.

[0487] The bubble generator may be arranged in the device so as to generate bubbles beforehand, simultaneously or cyclically with respect to the emission of the acoustic waves.

[0488] The bubble generator can implement any technique suitable for generating bubbles, for example using the aforementioned mechanical, physical, chemical or electrochemical means.

[0489] The bubble generator can thus implement the techniques of decompression of liquids, creation of a turbulent flow or supply of energy, as described above. Hair treatment process

[0490] The invention also relates to a method for treating human hair, in particular for cleaning and / or bleaching the hair, in contact with a fluid, in particular a cosmetic composition, within which bubbles of a gas are present and / or are generated, the method comprising the step consisting of: subjecting the gas bubbles to acoustic waves emitted by a transducer in the vicinity of the hair to be treated, in order to cause the collapse of said bubbles and generate a mechanical shock on the surface of the hair to be treated, in particular to remove impurities and / or dyes.

[0491] The transducer may in particular belong to a treatment device according to the invention, as defined above, comprising a hair guiding and / or combing member.

[0492] The method may thus comprise guiding and / or combing the hair upstream and / or downstream of its passage through a treatment space, and / or in the treatment space itself.

[0493] The method may comprise guiding the hair in order to bring it into or maintain it in the treatment space, and / or to maintain it during its passage in the treatment space at a predefined distance from the surface of emission of the acoustic waves, in particular to prevent it from moving away more than a given distance from the surface of emission of acoustic waves.

[0494] The method may comprise vibration and / or rotation and / or longitudinal and / or transverse movement of the guiding and / or combing member and / or the transducer.

[0495] The method according to the invention may comprise the step of adjustment by the user of the distance between a guide surface of the guide and / or combing member and the emission surface of the transducer, in order to adapt the method to the desired treatment and / or to the hair treated.

[0496] The method may include the step of adjustment by the user of the internal section, in particular the diameter, of a cavity defined by the guide and / or combing member, in order to adapt the method to the hair treated and to the desired treatment.

[0497] The method may include the step of adjusting by the user the distance between a proximal portion, closest to the transducer, of the guiding and / or combing member and a distal portion, furthest from the latter. This adjustment may make it possible to adapt the method to the hair and / or the desired treatment.

[0498] The method according to the invention may comprise heating by the device and / or diffusion of light by the latter, in order for example to activate certain compounds present in the fluid, in particular in the cosmetic composition.

[0499] The hair treatment method may include a step of applying the fluid, in particular the cosmetic composition, to the lock of hair.

[0500] The fluid, in particular the cosmetic composition, may be brought into the treatment space by the guide and / or combing member, in particular when the latter is hollow or when a conduit runs through it. This application may be carried out continuously or not. The fluid, in particular the cosmetic composition, may be delivered to the hair through one or more orifices of the guide and / or combing member. Alternatively, the fluid, in particular the cosmetic composition, is delivered in another way, for example by an application element other than the device, or applied to the hair in a way other than with the device.

[0501] Generally speaking, the fluid, in particular the cosmetic composition, can in itself, by virtue of its formulation, already contribute to the bleaching and / or removal of impurities or colorants that it is desired to remove by the action of the bubbles subjected to the acoustic waves. The action of the bubbles subjected to the acoustic waves can accelerate this process or improve it. Thus, the association of the wave generated by the collapse of the bubbles in combination with the action of the fluid, in particular the cosmetic composition, can have, by synergy, an effect greater than that of the waves alone or that of the fluid, in particular the cosmetic composition, alone.

[0502] Preferably, the bubbles are generated within the fluid, in particular the cosmetic composition, by acoustic waves, which can then cause their collapse. The process can thus involve the application of a bubble-free fluid, the bubbles forming under the action of acoustic waves. This avoids the use of a bubble generator, and simplifies the production of the device.

[0503] Alternatively, or additionally, the fluid, in particular the cosmetic composition, is applied, initially, with bubbles already present within it or not, then exposed in a second stage, after its application to the lock of hair, to acoustic waves to cause shock waves following the collapse of the bubbles. The bubbles can be formed using a bubble generator of the device, operating for example by electrolysis.

[0504] For example, the user first applies a cosmetic composition in the form of a foam to the area to be treated, for example by spraying it onto said area, in particular along the strand, and then brings a treatment device into contact with the composition, to subject it to acoustic waves.

[0505] The fluid, in particular the cosmetic composition, can be applied continuously, that is to say that a circulation of the fluid, in particular of the cosmetic composition, is established in contact with the hair to be treated, this circulation being for example in a closed or open circuit.

[0506] When the circulation takes place in a closed circuit, the fluid, in particular the cosmetic composition, can be recycled at least partially. An additional quantity of fluid, in particular cosmetic composition, can be introduced permanently or intermittently into the circuit to compensate for losses.

[0507] In an open circuit, the fluid, in particular the cosmetic composition, is not recycled for the implementation of the process, and for example is eliminated into a collection tank or directly with the wastewater.

[0508] The circulation of the fluid, in particular of the cosmetic composition, is carried out for example with a flow rate of between 0.01 mL per second and 50 mL per second.

[0509] The method may comprise the dissolution of a fabric or non-woven sleeve, in particular made of polymer, covering a portion of the guide and / or combing member. This dissolution may be carried out as the fluid exits, for example through one or more orifices located on the guide and / or combing member.

[0510] The method according to the invention can be applied to hair that has undergone a coloring treatment, for example a so-called permanent coloring, a so-called semi-permanent coloring, a so-called tone-on-tone coloring, a coloring of highlights, a so-called sweeping coloring, a coloring with henna, or even by the use of a tinted shampoo.

[0511] The method according to the invention can be implemented to bleach hair, without being followed by a new coloring within 24 hours. The method can also be implemented, then followed within 24 hours by a new treatment for coloring the bleached hair using the ultrasound treatment according to the invention.

[0512] The method according to the invention can also be implemented to create a bleaching gradient and / or at least one pattern along the strand by varying, for example, the intensity of the treatment and / or the duration depending on the position along the strand.

[0513] The method can be implemented to bleach the hair only on the outside of the hair (i.e. on the side opposite the scalp), so as to give a balayage effect to the hair.

[0514] The method according to the invention, when used on hair to bleach it in conjunction with a chemical bleaching means, can make it possible to reduce the content of bleaching active ingredients and / or the exposure time to these active ingredients.

[0515] Thus, the method may comprise exposing the hair both to acoustic waves in accordance with the invention and to at least one bleaching active agent, for example a persulfate, an alkali or an oxidizing agent, such as hydrogen peroxide, potassium, sodium or ammonium salts of perborate or percarbonate.

[0516] The risks of irritation linked to the use of bleaching active ingredients can be reduced or even eliminated.

[0517] The method may comprise the selective treatment of a portion of the hair, by generating the emission of acoustic waves only in certain areas of the hair, for example by operating the device intermittently.

[0518] The invention also relates, independently or in combination with the above, to a method for treating at least one lock of hair having undergone a permanent or semi-permanent coloring treatment, in which said lock is exposed, in contact with a fluid, such as a cosmetic composition containing at least one surfactant, to acoustic waves generated by a transducer, of frequency and intensity chosen to generate bubbles in the composition by cavitation, and to cause them to collapse, the bubbles present in the treatment zone being or having been mainly generated by the transducer.

[0519] By "permanent coloring", or oxidation coloring, we mean a dye that covers the entire head of hair while penetrating to the heart of the hair and which, as its name indicates, is made to last.

[0520] By "semi-permanent coloring" we mean a type of coloring, notably without ammonia, which colors superficially without reaching the heart of the hair, and which fades gradually over time with shampooing.

[0521] The bleaching process according to the invention may include, after exposure to acoustic waves, drying the hair using a hair dryer.

[0522] The bleaching process may be followed by coloring, for example a co permanent or semi-permanent hair color, with the same color as that used to color the hair that was treated to bleach it, or with a different color.

[0523] Throughout the following description, the invention is implemented with a fluid which is an aqueous medium. However, it can be implemented more generally with any fluid compatible with use at home by a consumer or in a hairdressing salon. Brief description of the drawings

[0524] The invention may be better understood by reading the detailed description which follows, non-limiting examples of its implementation, and by examining the attached drawing, in which:

[0525] [Fig 1] schematically illustrates the use of an example of a treatment device according to the invention,

[0526] [Fig.2] is a schematic view, in longitudinal section, of another example of processing device for implementing the invention,

[0527] [Fig.3] is a view similar to [Fig.2] of an alternative implementation of the invention,

[0528] [Fig.4] schematically and partially represents an alternative embodiment of the device according to the invention,

[0529] [Fig.5] is a perspective view of the variant of [Fig.4],

[0530] [Fig.6a] and [Fig.6b] represent details of the example of [Fig.4],

[0531] [Fig.7] schematically and partially represents a circuit variant fluidic according to the invention,

[0532] [Fig.8] is a block diagram illustrating an example of operation of the device of the invention,

[0533] [Fig.9] schematically and partially represents another circuit variant fluidic according to the invention,

[0534] [Fig. 10] schematically and partially represents an alternative embodiment,

[0535] [Fig. 1 la] to [Fig. 1 le] schematically and partially illustrate variants of transducers according to the invention,

[0536] [Fig. 12a] and [Fig. 12b] schematically and partially represent examples of transducers having reliefs,

[0537] [Fig. 13a] to [Fig. 13c] schematically and partially represent examples of such reliefs,

[0538] [Fig. 14] schematically and partially represents an example of a vibrator according to the invention,

[0539] [Fig. 15] illustrates in a partial and schematic manner another example of a device of treatment according to the invention,

[0540] [Fig. 16] partially and schematically represents the possibility of adjusting the distance at rest between the transducer and the grid of the device of [Fig 1],

[0541] [Fig.17a], [Fig.17b], [Fig.17c], [Fig.17d], [Fig.17e] and [Fig. 17f] partially and schematically represent alternative embodiments of the grid in examples of devices according to the invention.

[0542] [Fig. 18a] to [Fig. 18e] schematically and partially represent spacer embodiment variants,

[0543] [Fig. 19a] and [Fig. 19b] schematically and partially represent other variant embodiments of the device according to the invention,

[0544] [Fig.20] schematically and partially represents another variant embodiment of the device according to the invention,

[0545] [Fig.21] partially and schematically represents an example of a signal modulated electrical current exciting the ultrasonic transducer(s),

[0546] [Fig.22] is a partial and schematic representation of an example of an electrical circuit comprising the transducer,

[0547] [Fig.23] partially and schematically represents an example of a treatment device according to the invention,

[0548] [Fig.24] a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0549] [Fig.25] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0550] [Fig.26] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0551] [Fig.27] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0552] [Fig.28] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0553] [Fig.29] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0554] [Fig.30] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0555] [Fig.31] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0556] [Fig.32] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0557] [Fig.33] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0558] [Fig.34] is a view similar to [Fig 1] of a variant of the treatment device according to the invention,

[0559] [Fig.35] represents the intensity of coloration inside the hair fibers for three hair samples,

[0560] [Fig.36] represents the rate of fluorescein coloration of the hair for the three same hair samples as in [Fig.14],

[0561] [Fig.37] represents locks of colored and untreated hair, A and B, and strands of colored and treated hair, C and D,

[0562] [Fig.38] represents the intensity of coloration in the hair for five samples of hair,

[0563] [Fig.39] represents the results of a statistical analysis of the coloring intensity for the same five hair samples as in [Fig. 16].

[0564] [Fig.40a], [Fig.40b], [Fig.40c], [Fig.40d], [Fig.40e], [Fig.41a], [Fig.41b], [Fig.41c], [Fig.41d], [Fig.41e], [Fig.42a], [Fig.42b], [Fig.42c], [Fig.42d], [Fig.42e], [Fig.43a], [Fig.43b], [Fig.43c], [Fig.43d], [Fig.43e], [Fig.44a], [Fig.44b], [Fig.44c], [Fig.44d], [Fig.44e], [Fig.45a], [Fig.45b], [Fig.45c] and [Fig.45d] represent calculated response surfaces illustrating examples of parameters for which satisfactory cleaning efficiency is obtained according to the method of the invention, and

[0565] [Fig.45e] represents an empty response surface illustrating an example of a com combination of parameters for which the desired cleaning efficiency is not obtained. Detailed description

[0566] The method according to the invention comprises the generation of bubbles within a cosmetic composition, and their collapse, thanks to exposure to acoustic waves.

[0567] [Fig 1] illustrates a first example of implementation of the invention, in which a cosmetic composition C is present on the surface of the keratin materials K to be treated, and a treatment device 1 is brought into contact with the composition C to emit acoustic waves within it.

[0568] Composition C may not contain bubbles before the emission of the acoustic waves. Alternatively, composition C already contains bubbles, for example in the form of foam, and bubbles are also formed by the acoustic waves.

[0569] Keratin materials K are, for example, made up of facial skin or hair.

[0570] For example, this involves cleaning the skin to remove traces of makeup more quickly and effectively.

[0571] The treatment device 1 comprises a handpiece which carries a sonotrode 4, in contact with the composition, and from which the acoustic waves are emitted.

[0572] The handpiece can be manipulated so as to leave a slight space with the keratin materials K and avoid contact of the sonotrode 4 with them.

[0573] Alternatively, the handpiece is arranged to maintain such a gap, thanks to one or more elements 49 intended to contact the keratin materials and set back from which the sonotrode 4 is located.

[0574] Under the effect of acoustic waves, bubbles are generated in composition C and then collapse on themselves which generates a shock wave, which proves effective in cleaning the skin.

[0575] In the example of [Fig 1], composition C is for example applied from a pressurized container, which generates a foam, then the handpiece carrying the sonotrode 4 is brought into contact with it.

[0576] The composition can still be applied, as illustrated in [Fig.2], by the device 1 which generates the acoustic waves.

[0577] In this figure, the device 1 comprises a treatment head 10 arranged to distribute the composition C onto the area to be treated, for example through at least one opening 31.

[0578] The device 1 may comprise, as illustrated, a chamber 32 in which the composition C circulates and at least one ultrasonic transducer 4 for emitting acoustic waves into the chamber 32. The transducer 4 is powered by a generator 15, which may or may not be part of the handpiece, being for example present within a base station to which the handpiece is connected by a cable.

[0579] Composition C can be brought into chamber 32 via a conduit 16, and come for example from a composition reservoir 22.

[0580] In the example of [Fig.2], the handpiece is moved along the area to be treated and the composition which is delivered through the opening 31 is not recycled.

[0581] In the variant of [Fig.3], a recycling of the composition is carried out.

[0582] In this example of [Fig.3], the device 1 used to implement the method according to the invention comprises at least one transducer 4 emitting acoustic waves in a chamber 32, as in the example of [Fig.2].

[0583] However, the composition C which is distributed through the opening 31 onto the area to be treated K is recovered by at least one conduit 27 with a view to being recycled.

[0584] In the example considered, this conduit 27 opens around the opening 31 so as to recover the composition which has been in contact with the area to be treated.

[0585] The device 1 may comprise, where appropriate, around the conduit 27 a sealing element 19 such as a flexible lip to contain the composition and facilitate its return through the conduit 27. The lip may consist of sub-lips between which the liquid can be recovered.

[0586] The conduit 27 communicates with a suction pump 20, for example an electric pump, which can, as illustrated, send the discharged composition into a filter 21. The latter can be arranged to stop, for example, particles suspended in the composition, such as skin debris removed during cleaning, for example.

[0587] The composition is returned to the chamber at the outlet of the filter 21.

[0588] The composition may come from a reservoir 22 shown schematically, for example carried by the handpiece.

[0589] This reservoir 22 makes it possible to fill the circuit in which the composition circulates during operation of the device, and to compensate for any losses in composition, in the event of non-recycling of part of it.

[0590] Figures 4 and 5, and the corresponding detailed views of Figures 6a and 6b, show another example of a device according to the invention, comprising an ultrasonic transducer 4, two reservoirs 22a and 22b, a pump 20 and a fluid circuit comprising conduits 23, 25 and 27 allowing the circulation of the composition C between the reservoirs 22a and 22b and the keratin materials K to be treated.

[0591] In the example considered, the device 1 is in the form of a handpiece comprising a handle 9 and a treatment head 10 comprising a spacer 7 in contact with the keratin materials K.

[0592] The device does not include a bubble generator other than the transducer 4, the bubbles being generated during the cavitation phenomenon using acoustic waves.

[0593] The transducer 4 is arranged relative to the spacer 7 so as to provide a space E between the surface for emitting the acoustic waves and the surface of the keratin materials K to be treated.

[0594] Bubble cavitation occurs in this space E, as illustrated in [Fig.6a].

[0595] The device 1 may comprise a grid 6 in contact with the keratin materials to to be treated, for example fixed on the spacer 7, comprising for example regular openings arranged in rows and columns, as shown in [Fig.6b].

[0596] The device 1 further comprises an electronic circuit 12 connected by a connector 120 to an electronic generator 40 supplying the transducer, as illustrated in [Fig.4]. This generator comprises, for example, an oscillator and a power stage.

[0597] The electronic circuit 12 may comprise a control unit capable of communicating with a human-machine interface 41, which may comprise a screen, in particular an LED screen and / or control buttons, or even communicate via a wireless link with a terminal such as a mobile telephone.

[0598] The human-machine interface 41 can make it possible to adjust certain operating parameters of the device, for example the intensity with which the acoustic waves are emitted.

[0599] The electronic circuit 12 can control the operation of the pump 20, in a battery 15 powering the device (in particular its charge) and receiving data from one or more sensors (not shown) such as a sensor for contact of the device on the skin.

[0600] In the latter case, the electronic circuit 12 may only start the pump 20 and the emission of acoustic waves when the area to be treated is in contact with the grid 6, in particular in a manner which allows the composition to be recycled.

[0601] The electronic circuit can also communicate with an optical detector 650, as shown very schematically in [Fig.5], making it possible to detect the presence of a compound to be removed from the surface of the skin, and possibly determine the quantity present.

[0602] As mentioned above, the composition circulation system, comprising the fluid circuit, the reservoir(s) and the pump, can be arranged in different ways.

[0603] In the example shown in Figures 4 and 5, the device 1 comprises two separate reservoirs 22a and 22b. The reservoir 22a is for example a reservoir of composition to be distributed; it is connected to the pump 20 which can, as illustrated, send the composition C to the treatment zone via a conduit 25 opening out via an outlet 250.

[0604] The reservoir 22b recovers the composition which has been in contact with the area to be treated by means of a conduit 27 which opens onto an outlet 270, as illustrated in [Fig.6a].

[0605] The device 1 may comprise, where appropriate, on the periphery of the end of the treatment head, a sealing element 19 such as a flexible lip to contain the composition and facilitate its return through the conduit 27.

[0606] The reservoirs 22a and 22b may be at least partially transparent, which may allow the user to visually check the level of filling and / or fouling, through, where appropriate, a transparent window provided in the handle. Each of the reservoirs and / or the assembly formed by the reservoir(s) and the fluid circuit is preferably removable, so that it can be cleaned or replaced easily by the user.

[0607] A filter can also be arranged in a conduit connecting the tanks 22a and 22b.

[0608] The filter can still be carried by the reservoir 22b, for example so as to allow its automatic replacement when the composition is exhausted and the tank is replaced.

[0609] In the variant illustrated in [Fig.7], the reservoirs 22a and 22b are directly connected to the treatment zone by conduits 25 and 27, respectively.

[0610] In this example, the pump 20 is connected to the reservoirs 22a and 22b without having any composition circulating within it; the pump makes it possible to generate a positive air pressure in the reservoir 22a of composition to be dispensed, and a negative pressure in the reservoir 22b of recovered composition, in order to maintain the cir- culation in conduits 25 and 27 between the treatment area and the tanks.

[0611] The pump 20 can also contribute to the generation of bubbles in the reservoir 22a, upstream of the distribution of composition on the treatment zone.

[0612] The device may also, in a variant, comprise a single reservoir 22, which may or may not comprise an internal filter, which may be removable.

[0613] For example, the composition is recovered using a suction system 28 such as a suction pump, which can be arranged at various locations in the fluid circuit, for example directly in the treatment head 7 where the composition is collected and held using the flexible lip 19, as illustrated schematically in [Fig.8].

[0614] The device 1 may comprise, as illustrated in [Fig.8], a treatment and purification unit 29 for the composition, which allows the composition to be recycled with a view to being returned to the keratin materials to be treated, the composition then circulating at least partly in a closed circuit.

[0615] The treatment and purification unit 29 is for example a filtration system, shown schematically in [Fig.8], comprising one or more filters arranged to stop particles suspended in the composition, such as skin debris removed during cleaning.

[0616] The filtration system may be arranged between the suction system 28 and the reservoir 22, as illustrated in [Fig.8].

[0617] In the variant illustrated in [Fig.9], the reservoir 22 comprises two compartments 220 and 225 separated by a piston 230. The compartment 220 comprises, for example, the composition C to be distributed and is directly connected to the treatment head by a conduit 25 which opens onto the treatment zone.

[0618] The composition is recovered by a conduit 27 which connects the treatment zone to a pump 20, the latter returning the used composition to the second compartment 225 of the reservoir 22.

[0619] A filter 21 may be disposed in the conduit 27 between the treatment zone and the pump 20, as illustrated.

[0620] The circulation is established thanks to the pump 20 and the movement of the piston 230 within the reservoir 22. In this example, the compartments 220 and 225 of the reservoir 22 do not communicate.

[0621] The reservoir 22 is preferably partly or completely transparent so that the user can estimate the position of the piston and the respective remaining levels of composition to be dispensed and used liquid.

[0622] The device may further comprise one or more control buttons 39, for example a power on or standby button, as illustrated in Figures 4 and 5.

[0623] The device is for example charged using a USB port (not shown) di directly placed on the body of the device, or by being placed on a base station provided for this purpose, and be charged by induction, or using any suitable connector.

[0624] The battery 15 can also be removed and charged separately. The device can also comprise, as illustrated in [Fig. 10], an outlet 31 for delivering the composition C and a transducer 4 arranged offset from the outlet 31. In this case, the composition deposited on the area to be treated K passes, after movement of the device relative to the area to be treated, under the transducer 4 where it is exposed to the acoustic waves.

[0625] The device may include an additional bubble generator 17.

[0626] A spacer element 49, which may be a flexible lip, may be used to space the transducer 4 away from the area to be treated to avoid direct contact with the skin, for example.

[0627] The transducer 4 or its sonotrode are preferably removable. Thus, they can be easily removed from the device in order to clean them.

[0628] It is also possible to interchange different transducers and sonotrodes, in particular to provide sonotrodes of different sizes and / or transducers generating waves of varying frequency and acoustic intensity, depending on the desired use of the device.

[0629] For this purpose, the transducer or sonotrode may include different means of attachment to the handpiece.

[0630] The fixing means are for example screw fixing means, as illustrated in Figures 11a and 11b.

[0631] The transducer 4 may have a threaded rod 102 at one of its ends, as illustrated in [Fig.11a], which can be screwed into a nut 103 fixed to the device, in particular in the treatment head.

[0632] Conversely, the transducer 4 may have a nut 103 on its upper face and the threaded rod 102 may be fixed to the treatment head 7, as shown in [Fig. 11b].

[0633] The removable transducer can also be fixed by snap-fastening, as illustrated in [Fig. 1 le], or by tightening, in particular by means of clamps 106, as illustrated in [Fig. 11d], or a seal 107, for example made of polymer or rubber, as illustrated in [Fig. 11e].

[0634] The surface for emitting the acoustic waves may have reliefs 420 where the bubbles may originate during cavitation, at different levels along the longitudinal axis X of the transducer.

[0635] These reliefs 420 can be monolithic with the sonotrode, as illustrated in [Fig. 12a], or can be formed on an added part 95 on the sonotrode, as illustrated in [Fig. 12b], which is for example fixed by screwing onto the sonotrode.

[0636] All or part of the reliefs 420 may have a distribution on the emission surface and / or a random size, as illustrated in [Fig. 13a].

[0637] Alternatively, the reliefs may have a predefined shape, for example pyramidal, as illustrated in [Fig. 13b], and be arranged in a regular arrangement, for example in a regular network, as illustrated in [Fig. 13c].

[0638] Preferably, the reliefs 420 have a height h, measured parallel to the longitudinal axis X of the sonotrode, between 0.001 mm and 50 mm, better still 0.01 mm and 30 mm, even better still between 0.1 and 1 mm.

[0639] The device may also include a vibrator 750, making it possible to subject at least part of the emission surface to additional vibrations of a frequency lower than that of the acoustic waves.

[0640] The vibrator 750 comprises for example a motor 751 driving an unbalanced mass 752 in rotation, as illustrated in [Fig. 14].

[0641] [Fig. 15] shows another example of device 1 according to the invention. The device 1 comprises a body 2 receiving a transducer 4, a spacer 7 in the form of a tip attached to the treatment head, and a grid 6 arranged in front of the transducer 4.

[0642] The transducer 4 comprises electroactive elements coupled to a sonotrode, typically made of metal, which defines an emission surface S through which the acoustic waves are emitted towards the keratin materials to be treated.

[0643] The body 2 of the treatment device 1 may be presented as a handpiece which is manipulated by the user so as to bring the grid 6 into contact with the area to be treated.

[0644] As illustrated in [Fig. 16], a composition C containing bubbles B is present when using the device 1 on the surface of keratin materials K to be cleaned.

[0645] Composition C is for example in the form of foam or another composition, applied to the keratin materials before bringing the device into contact with them. Composition C can also be delivered by the device 1, or be partly present before bringing the device 1 into contact with the keratin materials and partly provided by the device.

[0646] Keratin materials K are, for example, made up of facial skin or hair.

[0647] Transducer 4 is in contact with composition C.

[0648] Under the effect of acoustic waves, the bubbles undergo a collapse on themselves which generates a shock wave, which proves effective in cleaning keratin materials K. Acoustic waves can also contribute to the formation of bubbles, if necessary.

[0649] Grid 6 can be made in different ways.

[0650] The grid 6 comprises at least one opening 300; it may comprise exactly one opening, as illustrated in [Fig. 17f], or exactly two openings, as illustrated in [Fig. 17a], or more.

[0651] The openings may be mostly, or all, of similar size, as shown in [Fig. 17b], [Fig.l7d] or [Fig. 17e]. They may be of various shapes, for example, square, round, or a portion of a disc or ring, as shown in [Fig.l7c],

[0652] The grid 6 preferably has a ratio of the total surface area of ​​the openings relative to the surface area of ​​contact with the keratin materials greater than or equal to 0.5, which makes it possible to benefit from openings that are wide enough to allow the shock wave generated by the collapse of the bubbles to reach the keratin materials K over a suitable surface area.

[0653] The grid 6 may be of circular outline, as illustrated in figures 16a to 17f or of another shape, for example polygonal.

[0654] The external face of the grid 6 may be flat, and oriented for example perpendicular to the longitudinal axis X.

[0655] The grid 6 may be in one piece, formed by machining or injection molding for example.

[0656] Its thickness can be chosen so as to give it the desired rigidity.

[0657] The grid can be made of metal, with a surface finish, on its face coming to the contact with keratin materials, smooth or rough. The grid is for example made of aluminum or aluminum alloy, or stainless steel. The grid can also be made of a rigid plastic material, or ceramic. The grid can also be composite, and include for example a frame embedded in a plastic matrix.

[0658] The grid may be made of a deformable and / or compressible material. The grid may thus be compressed during use to a thickness ensuring a minimum distance between the emission surface and the surface of the materials to be milked.

[0659] A smooth surface condition can facilitate movement on the skin in particular, while a rough surface condition can exert a mechanical action contributing to cleaning the skin.

[0660] Each opening of the grid may be delimited by a sharp edge, on the face of application to the keratin materials. Such a sharp edge may promote cleaning, by scraping the keratin materials during the movement of the grid in contact with them.

[0661] The device according to the invention may comprise, as illustrated in [Fig. 15], a spacer 7 comprising several support legs 115 each extending axially over less than 360° around the axis X of the transducer, in front of the emission surface. S.

[0662] The grid 6 can be carried, as in the example considered, by the spacer 7; in this case, the spacer can comprise a holding part 110 of the grid 6, the support leg(s) 115 acting as a rigid connection between a fixing part 100 of the spacer to the device and the holding part 110.

[0663] The device may not include a grid, but only a spacer 7 defining a contact surface with the keratin materials to be treated.

[0664] The spacer 7 may alternatively be carried by the transducer 4 directly, with, if necessary, a damper between the two to limit the transmission of vibrations from the transducer to the spacer.

[0665] The spacer 7 makes it possible to maintain the transducer 4 at a distance d from the keratin materials, in order to avoid direct contact between the emission surface S and the latter. When the device comprises a grid 6 carried by the spacer 7, the distance d is at least equal to the thickness of the grid 6.

[0666] The spacer 7 is preferably laterally openwork, these openings being for example defined by the spaces between the support legs 115, as illustrated in [Fig.15], which makes it possible to observe the position of the transducer 4 and to facilitate the circulation of the composition between the transducer 4 and the keratin materials.

[0667] In the example of [Fig. 15], the spacer 7 comprises three support legs 115 arranged at 120° to each other, around the longitudinal axis X of the device. These support legs 115 provide the connection between the fixing part 100 and the grid holding part 110, both of which are annular in shape.

[0668] Other forms of spacers are possible.

[0669] For example, the spacer 7 may comprise a single support leg 115, extending substantially perpendicular to the emission surface S of the transducer 4, as illustrated in [Fig. 18a], and bearing by its free end directly against the keratin materials.

[0670] The spacer 7 may similarly comprise three or four rectilinear support legs 115 arranged at 120° or 90° to each other around the longitudinal axis X of the device. These legs may be parallel to the longitudinal axis X, as illustrated in [Fig. 18b], or inclined obliquely outwards so as to improve the stability of the support of the device on the keratin materials, as illustrated in [Fig. 18c].

[0671] The support leg(s) 115 may also be connected to a distal portion 116 extending transversely to the legs, and facing or around (in front view) the emission surface S of the ultrasonic waves.

[0672] This distal part 116 is for example annular in shape, as illustrated in [Fig. 18d], or even in the shape of a bar, as illustrated in [Fig. 18e].

[0673] The leg(s) and / or distal portion may be made of a rigid material, for example metal or rigid plastic, or of a semi-rigid or flexible material.

[0674] The spacer may be monolithic with the body of the device, or in the form of a removable tip.

[0675] The spacer 7, when in the form of a tip, can be fixed to the body 2 of the device by different means, for example by tightening using a screw 15, as illustrated in [Fig. 15].

[0676] The axial position of the spacer can be adjustable along the longitudinal axis X of the device relative to that of the transducer; for example, the spacer can be engaged more or less on the body of the device 2 and then fixed in the chosen position using the screw 15, as illustrated in [Fig 1].

[0677] This adjustable position makes it possible to precisely adjust the distance d at rest between the transducer 4 and the keratin materials, depending on what is required.

[0678] The end piece 7 can also be extendable at the level of the support legs 115. The legs 115 are for example each adjustable in height, the adjustment being carried out for example to adapt the grid position to the morphology of the keratin materials to be cleaned. This can make it possible to obliquely tilt the plane of the grid relative to the X axis, for example.

[0679] The support leg(s) 115 of the spacer 7 may also comprise an elastic return means 8, for example one or more springs, as illustrated very schematically in [Fig.19a], or a telescopic connection, as illustrated in [Fig.19b].

[0680] Such an elastic means 8 makes it possible to vary the spacing d between the transducer 4 and the keratin materials K as a function of the pressure with which the spacer is pressed against the keratin materials K to be cleaned, and / or to maintain a certain application pressure during the movement of the device, and for example to adapt to any reliefs of said materials.

[0681] As illustrated in [Fig.20], the device 1 may comprise one or more supply conduits 25 running through the spacer 7 from a composition reservoir 22, in particular extending along the support leg(s) 115, and opening out via at least one outlet 250, located close to the area to be treated during use.

[0682] The supply conduit(s) 25 may extend into the grid and / or the support part 110 of the grid 6, when the latter is carried by a spacer 7. The device 1 comprises, for example, several outlets 250 located on the grid 6 or on the support part 110 of the grid 6 (not shown).

[0683] [Fig.23] illustrates a treatment device 1 according to the invention comprising a transducer 4, having an emission surface S for acoustic waves in a cosmetic composition C, and a guide member 70 for a lock of hair K, to guide the K hairs as they pass through the treatment area.

[0684] The treatment device 1 may be in the form of a handpiece, not shown, operating autonomously or connected to a base station.

[0685] The transducer 4 may be removably or non-removably attached to the device.

[0686] The guide member 70 can be made in one or more parts, these parts being able to be removable and / or assembled and / or replaced and / or modified by the user.

[0687] The transducer 4 is powered by an electric generator, not illustrated in this figure, which may be part of the device 1, being for example integrated into the handpiece, or connected to it by a flexible cable.

[0688] The guide member 70 may be mounted removably or not on the rest of the device 1, and movable or not relative to the latter, for example between a configuration of use where the member 70 guides the hair K and a disengaged configuration where it is distant from the transducer 4 and allows the lock of hair K to be introduced. It may also be fixedly mounted on the device 1, providing a passage allowing the lock of hair K to be treated to be introduced.

[0689] The guide member 70 may be arranged to define a space with the emission surface S in which the hair K passes during the treatment, and extend at least partially opposite the emission surface S as illustrated, having for example a guide portion 71 defining a guide surface 72 substantially parallel to the emission surface S.

[0690] The guide surface 72 may be flat or have another shape, suitable for movement on the wick, for example circular.

[0691] The guide surface 72 may have a width L greater than or equal to that of the emission surface, for example having a width L between 1 mm and 180 mm, the emission surface being for example having a width between 1 and 150 mm.

[0692] The guide member 70 may comprise a support portion 73 which extends for example along the transducer 4 and is connected to the body of the device 1 at an end opposite the guide portion 71 by any suitable means.

[0693] The guide member 70 can advantageously be used to bring the cosmetic composition C into the treatment zone. For this purpose, the guide member 70 can be traversed by at least one conduit 74 which opens through one or more orifices 75 into the guide portion 71 opposite the emission surface S.

[0694] The conduit 74 is connected to a fluid circuit which ensures, for example, the circulation of the composition by taking it from a reservoir.

[0695] The distance D between the emission surface S and the guide surface 72 is for example between 0.1 mm and 30 mm.

[0696] This distance D can be fixed, or adjustable, for example by means of mounting by particular of the guide member 70 on the device 1, allowing the user to move the guide member 70 relative to the transducer 4 as required.

[0697] The orifices 75 are for example regularly spaced along the guide portion 71, as illustrated, but alternatively they can be spaced differently.

[0698] The orifices 75 are for example circular, but can also be produced in another form, for example in the form of one or more slots.

[0699] To use the device 1 of [Fig.23], the user can engage a lock of hair K between the guide portion 71 and the transducer 4, and move the device 1 along the lock of hair K, for example from the roots of the hair towards the tips.

[0700] During this movement, the composition C is delivered into the treatment zone by the device 1, in particular thanks to the distribution orifices 75.

[0701] The composition C present in the treatment zone, in contact with the hair K, is subjected to the action of the acoustic waves emitted by the transducer 4.

[0702] Bubbles are generated by cavitation in the treatment area, then collapse creating shock waves that participate in cleaning and / or bleaching the hair K.

[0703] Composition C delivered to the treatment area may be discharged outside the device, or recycled.

[0704] The guide member 70 can also be made so as to comb the hair K upstream or downstream of the treatment zone, or even at the level of the latter. This can make it possible, for example, to present a lock of more uniform thickness opposite the emission surface S, the lock engaged in the device being divided by teeth and / or bristles and / or engravings and / or micro-reliefs, into smaller locks that are easier to access.

[0705] [Fig.24] shows a variant of the guide member 70 which makes it possible to carry out such combing and which differs for this purpose from the guide member 70 of [Fig.23] by the presence of at least one row of teeth 80, shown schematically.

[0706] These teeth 80 extend for example, as illustrated, with their longitudinal axis Y parallel to the longitudinal axis X of the transducer 4.

[0707] The teeth 80 may extend opposite the emission surface S, as illustrated, or alternatively are offset relative to this surface to comb the hair K upstream or downstream of it.

[0708] The guide member 70 may comprise both teeth 80 and orifices 75 for dispensing the composition C, as illustrated.

[0709] These orifices 75 open for example between the teeth 80.

[0710] The guide member 70 may comprise combing and / or guiding reliefs. elsewhere than opposite the emission surface S, for example on the opposite side as illustrated. In [Fig.24], a row of additional teeth 81 opposite the teeth 80 has thus been shown.

[0711] The height of the teeth 80 and 81 of the combing member 70 of [Fig.24] is for example of the order of 0.5 mm to 20 mm.

[0712] Of course, the invention is not limited to a particular tooth shape.

[0713] In the example of [Fig.25], the teeth 80 are hollow and in communication with the conduit 74 so as to distribute the composition C through orifices made in the teeth, not visible in this figure.

[0714] The guide member 70 may retain, as illustrated, distribution orifices 75 on the guide portion 71 which carries the teeth 80 and 81. Alternatively, the composition, C, is only distributed through the orifices provided on the teeth 80.

[0715] [Fig.25] also illustrates the possibility for the guide member 70 to have one or more lateral guide surfaces 76, between which the lock of hair is held as it passes through the treatment zone.

[0716] For example, the device comprises a lateral guide surface 76 defined by the support portion 73 and another by a return 77 directed inwards.

[0717] Where appropriate, as illustrated, the return 77 is hollow and communicates with the conduit 74 so as to distribute the composition C through at least one orifice (not visible) opening towards the treatment zone.

[0718] The emission surface S of the transducer 4 may also have teeth 46 and / or bristles 47 and / or engravings and / or microreliefs and / or spikes, in particular metallic, so as to comb the hair K upstream or downstream of the treatment zone, or even at the level of the latter. The emission surface S of the transducer 4 may comprise the same type of reliefs as the guide member 70, or alternatively different reliefs.

[0719] [Fig.26] shows schematically a variant of device 1 in which the emission surface S comprises teeth 46 or other reliefs making it possible to contribute to the combing and guiding of the lock of hair K.

[0720] These teeth 46 or other reliefs extend for example, as illustrated, with their longitudinal axis Z parallel to the longitudinal axis X of the transducer 4.

[0721] The teeth 46 or other reliefs may be arranged, as illustrated, so as to be inserted between the teeth 80 of the guide member 70.

[0722] [Fig.27] schematically shows a variant of device 1 which also allows combing to be carried out and which differs from the device 1 shown in [Fig.26] by the presence of bristles 47 on the emission surface S and bristles 82 on the guide member 70, the bristles 47 and 82 being able to be natural and / or synthetic.

[0723] The emission surface S of the transducer can be defined by a removable part and replaceable, so as to offer different solutions for guiding and / or combing the hair K depending on the guide member 70 used.

[0724] The guide member 70 and the transducer 4 may be mounted on the device 1 so as to be movable relative to each other and / or relative to the device 1; for example, they are moved longitudinally, transversely, vibrate and / or rotate.

[0725] In particular, the guide portion 71 of the guide member 70 may be rotatable about its longitudinal axis W, as illustrated in [Fig.27], being for example driven by a motor or free to rotate. The guide portion 71 may rotate, opposite the emission surface S, while the lock of hair K passes between the guide member 70 and the transducer 4, this making it possible for example to guide and / or comb the lock of hair K as it passes.

[0726] The transducer 4 of [Fig.28] can rotate around its longitudinal axis X. The guide member 70 and the transducer 4 of [Fig.28] can also be moved longitudinally along the axis X in order to bring the guide 72 and emission S surfaces closer together or further apart, for example to adapt the treatment to the thickness of the lock of hair K. The guide member 70 can in particular be returned to a rest position by means of an elastic return means 730, for example a spring, carried by the support portion 73.

[0727] The device 1 may comprise a spacer element 7, also called a spacer, as mentioned previously.

[0728] This spacer element 7 can make it possible to maintain the hair K at a predefined distance from the emission surface S. This spacer element 7 can be part of the guide member 70 or not.

[0729] For example, the spacer element 7 is carried by the guide member 70, being for example fixed to the support portion 73, as illustrated in [Fig.29].

[0730] The spacer element 7 is permeable to the acoustic waves emitted by the transducer 4, and defines with the guide portion 71 the treatment zone in which the hair K passes to be treated.

[0731] The spacer element 7 is for example in the form of a grid, for example made of a metallic material or plastic.

[0732] In [Fig.29], the distribution of composition C is illustrated by orifices 75 of the guide member, but as a variant, composition C can be brought by any other means into the treatment zone, or even be already present on the hair K introduced into the treatment zone.

[0733] ​​The device variant of [Fig.30] comprises a treatment head 10 which ensures circulation of the composition C between a supply conduit 25 and a return conduit 27.

[0734] The composition can thus circulate in the treatment zone between the conduits 25 and 27.

[0735] The circulation of the composition is for example ensured by an electric or manual pump, not shown.

[0736] The treatment head 10 may comprise a sealing tip, not shown, which is applied to the hair around the treatment area to limit composition losses during treatment. This sealing tip may be applied to a bearing surface, not shown, which is folded down onto the treatment head 10 when using the device 1, the treatment head 10 being for example carried by a first jaw of the device 1 and the bearing surface by a second opposite jaw, articulated on the first, in the manner of a hair straightener.

[0737] The guide member 70 may extend at least partially inside the treatment head 10 during use, as schematically illustrated in [Fig.30], to hold the hair K to be treated in the treatment area.

[0738] The hair K may in particular be held by the guide portion 71 of the guide member 70 at a distance from the emission surface S less than or equal to a predefined value.

[0739] The guide member 70 can be carried by the aforementioned second jaw.

[0740] The guide member 70 may, as illustrated in [Fig.31], comprise a portion hollow guide 71, for example tubular in shape, defining a cavity 710 for guiding the hair K to be treated, in particular open at two opposite ends 711 and 712.

[0741] The cavity 710 may or may not be of constant cross-section.

[0742] In this example, the lock of hair K is introduced into the cavity 710 by end 711 and exits through the opposite end 712.

[0743] The inner surface 716 of the cavity 710 may have reliefs which participate in the combing and / or retention of the hair. These reliefs may be in the form of ridges or teeth 713.

[0744] The guide portion 71 may be deformable, in particular may have its diameter varied under the action of a means of adjusting the device, for example using a clamping member such as a clamp, to adapt the device to the lock of hair and the desired treatment.

[0745] The guide portion 71 may be permeable to acoustic waves. Alternatively, it may form all or part of the transducer, in particular the sonotrode.

[0746] The device may be configured such that the transducer 4 is movable along the guide portion 71, for example with its emission surface S facing the outer surface 714 of the guide portion 71 as illustrated. The movement of the transducer 4 is carried out for example in a motorized manner, the transducer 4 carrying out for example back and forth movements along the guide portion. or being moved manually by the user.

[0747] The transducer 4 can also rotate around the guide portion 71, preferably keeping its emission surface S opposite the outer surface 714 of the guide portion 71. The rotation of the transducer can be motorized or carried out manually by the user, for example to adjust the side of the hair which is treated.

[0748] The guide portion 71 may also be movable, for example with a displacement thereof along its longitudinal axis W, or with a rotation around its longitudinal axis W. The displacement of the guide portion 71 may be motorized or not.

[0749] The device 1 may comprise, where appropriate, several transducers 4, in particular two transducers 4, as illustrated in [Fig. 32]. These two transducers 4 may be diametrically opposed. They may be fixed relative to each other and to the guide portion 71, or movable relative to the latter, and for example be moved or movable independently of each other.

[0750] The presence of several transducers makes it possible to increase the efficiency of the device 1, for example by making it possible to simultaneously treat two opposite sides of the hair and / or to obtain a greater density of bubbles.

[0751] The emission surface S of the transducer(s) 4 may have a concave shape towards the guide portion, so as, for example, to best match the outer surface 714 of the guide portion 71, as illustrated in [Fig.32].

[0752] The guide member may, as illustrated in this figure, have a slot 715 along the portion 71, between the two ends 711 and 712. This slot 715 may make it easier to introduce the lock of hair K into the cavity 710.

[0753] The cavity 710 can also be defined by a guide portion 71 comprising two parts 78 and 79 movable relative to each other, in particular in the form of jaws, as illustrated in [Fig.33], the movement of said parts taking place between a spaced-apart configuration for introducing a lock of hair K between them and a close-together configuration for treating the hair.

[0754] The jaws 78 and 79 may be carried by the support portion 73 of the guide member 70, as illustrated. They may be removably or non-removably attached to the support portion 73.

[0755] The distance E between the two jaws 78 and 79 can vary between 0 mm in the close configuration and 50 mm in the spaced configuration.

[0756] The two jaws 78 and 79 can be moved relative to each other, along the X axis, in order to enlarge or narrow the distance E, for example to adapt the treatment to the thickness of the lock of hair K to be treated.

[0757] Each jaw 78 or 79 may have on its surface opposite the other jaw, teeth 78d and 79d and / or bristles or other reliefs, allowing in particular to divide the strand of hair K to treat it better.

[0758] The jaw 78, proximal to the transducer 4, is preferably permeable to the acoustic waves emitted by the latter and may include holes for this purpose, for example be made in the form of a grid or even in a specific material permeable to acoustic waves.

[0759] As illustrated in [Fig.33], the guide member 70 may have two lateral guide surfaces 76, one of which is defined by the support portion 73 and the other by a return 790 of the lower jaw 79, directed inwards.

[0760] The space between the two jaws 78 and 79 is, as a variant, closed on the side opposite the support portion 73, by a closing part 791, as shown in [Fig.34].

[0761] In the example of this figure, the support portion 73 and the closing part 791 comprise for example at least one elastic return member 500, for example one or more helical springs, allowing the jaws 78 and 79 to come together and urging them towards a rest position, for example the close configuration or the separated configuration depending on the variants. Examples of hair strand treatment

[0762] Example 1

[0763] A confocal microscopy analysis of natural strands is carried out in order to study, using the passive diffusion of a fluorochrome in the fiber, whether the integrity of the cuticle is altered by the treatment device.

[0764] Three hair samples are prepared, namely: - sample 1: a lock of uncolored and untreated natural hair used as a reference, - sample 2: a lock of the same natural, uncolored hair treated with two passes of the treatment device according to the invention, emitting ultrasound at a frequency of 33.4 kHz, in contact with a cosmetic composition C such as a mousse containing soap-type surfactants (partially neutralized long-chain fatty acids), - sample 3: a lock of the same natural, uncolored hair treated with ten passes of the treatment device according to the invention, emitting ultrasound at a frequency of 33.4 kHz, in contact with the same composition C.

[0765] The three strands of hair are then stained for microscopic study with a hydrophilic fluorochrome, namely fluorescein.

[0766] Sections of the strands are then observed under a confocal laser scanning microscope, in order to study the diffusion of fluorescein inside the hair.

[0767] The images obtained are analyzed using software. A first analysis is made on the intensity of coloring inside the fiber, the results are visible in [Fig.35].

[0768] A second analysis is made on the fluorescein staining rate. The results are visible in [Fig.36].

[0769] It is found that the intensity of coloration inside the hair fiber is low, between 6.2% and 6.5%, and of the same order of magnitude for the hair serving as reference and the hair treated with ultrasound in accordance with the invention. This means that the integrity of the cuticle of the treated hair has not been altered. Ultrasound does not damage the hair sheath.

[0770] Example 2

[0771] A transmitted light analysis of colored strands is carried out in order to visualize the reduction in thickness and to quantify the intensity of dye inside the fiber of the treated hair.

[0772] Five hair samples are prepared, namely: - sample 1: a lock of uncolored and untreated natural hair used as a reference, - sample 4: a lock of the same hair colored with the product “Colorista Washout L'OREAL PARIS” and not treated, visible in [Fig.37] A, - sample 5: a lock of the same hair colored with the product “Colorista Washout L'OREAL PARIS” and treated by ten passes of the treatment device according to the invention, emitting ultrasound at a frequency of 33.4 kHz, visible in [Fig.37] B, - sample 6: a lock of the same hair colored with the coloring “Majirouge 6.66 L'OREAL PRO” and not treated, visible in [Fig.37] C, - sample 7: a lock of the same hair colored with the coloring “Majirouge 6.66 L'OREAL PRO” and treated by ten passes of the treatment device according to the invention, emitting ultrasound at a frequency of 33.4 kHz, visible in [Fig.37] D.

[0773] Sections of the strands are observed under a confocal laser scanning microscope, in transmitted light.

[0774] The following observations are made on the grayscale images obtained by confocal microscopy: - the uncolored and untreated hair of the reference strand (sample no. 1) has a uniform light gray shade, - hair colored with the product “Colorista Washout L'OREAL PARIS” and not treated (sample no. 4) mainly shows a surface coloring with a more or less thick dark crown but mainly located at the edges, - hair colored with the “Majirouge 6.66 L'OREAL PRO” coloring and not treated (sample no. 6) has a much darker and more core coloring since the hair is almost entirely colored, - the hair treated with ultrasound (samples no. 5 and 7) presents a less intense coloration compared to their respective colored reference, which highlights the interest of the treatment for bleaching colored hair while minimizing the impact on the integrity of the hair.

[0775] The analysis is performed by quantifying the average hair coloring intensity based on a gray scale from 0 to 100 with 0 = white and 100 = black. The results of the analysis are visible in [Fig.38].

[0776] After 10 ultrasonic passes on strands of colored hair, a reduction in coloring of 34% was observed for the product “Colorista Washout L'OREAL PARIS” and of 23% for the coloring “Majirouge 6.66 L'OREAL PRO” 6.66.

[0777] A statistical analysis of the coloration data was also carried out, reproduced in [Fig.39]. This analysis confirms that the difference between the measured mean values ​​is statistically different within a 95% confidence interval.

[0778] Of course, the invention is not limited to the examples which have just been described.

[0779] Thus, the guide member can be given other shapes.

[0780] The use of the device can be carried out according to the following steps, given as an example for a device comprising one or more removable reservoirs, a removable transducer or sonotrode, and / or a treatment head possibly equipped with additional elements such as a spacer, grid, etc.: - the user selects the fluid, in particular the cosmetic composition, depending on the treatment he wishes to carry out and fills the reservoir, or inserts a pre-filled reservoir (for example, single-use) into the handpiece. - The user selects the type of sonotrode and the elements in contact with the keratin materials to be used depending on the area he wishes to treat and attaches them to the rest of the device. - The user turns on the device with the on / off button and selects a program which can be viewed on a screen. - The start of the program can be associated with an audible signal, a vibration and / or a light indication. - The user applies the treatment head in contact with the keratin materials, which triggers the operation of the pump and the transducer using a contact sensor. - The pump generates a vacuum allowing a flexible lip placed on the end of the treatment head to adhere to the keratin materials, and to create a closed space between the surface emitting the ultrasonic waves and the surface of the materials to be treated. - The fluid is circulated in the space thus created. The transducer generates acoustic waves which cause the cavitation of the bubbles in the treatment area. - The fluid used is recovered in a second tank, or a second compartment of the tank; it can be filtered and reintroduced into the fluid circuit, thus making several passes in the treatment zone. - The user can see the level of contamination of the recovered fluid. The user can empty the tank containing this fluid at the end of its treatment or earlier, if necessary. - The device stops working for safety reasons when the user removes the treatment head from the keratin materials, if an excessive temperature rise is detected, or when it is detected that the device is static. - Once treatment is complete, the user can place the device back on a base to recharge it, or remove the battery to recharge it separately. - The user can also launch a cleaning program for the device by filling the tank with a specific product and placing the device on a dedicated surface to close the fluid circuit for cleaning. Examples of skin treatment

[0781] Artificial skin samples (BIOSKIN brand) are prepared on which a tenacious foundation is applied to a thickness of approximately 6 pm + / - 20%.

[0782] Leave to dry for at least 20 minutes at room temperature. Alternatively, leave for 15 minutes at room temperature and finish drying for 2 minutes with a hairdryer.

[0783] The composition is for example one of the compositions C1 to C5 mentioned below.

[0784] The acoustic waves are generated by an ultrasonic transducer 13 excited by a sinusoidal electrical signal U of frequency approximately 34 kHz, modulated in slots, as illustrated in [Fig.21], delivered by a generator G.

[0785] The amplitude of the voltage U can be adjusted by the user during testing by acting on the generator.

[0786] The slots are characterized by a pulse duration Ton and a duty cycle a = , with Toff the duration of the “low” or “passive” state over a period.

[0787] For example, a sonotrode 4 as illustrated in [Fig 1] is used to emit the acoustic waves, which is moved slowly in contact with the composition, without touching the foundation film.

[0788] The sonotrode comprises, for example, a ceramic piezoelectric type transducer system.

[0789] The nominal frequency of the transducer is for example approximately 34kHz.

[0790] The sonotrode is for example made of titanium.

[0791] The transducer comprises, for example, ceramics separated by an insulator and mounted together by clamping.

[0792] The diameter of the sonotrode is for example approximately 1.8 cm, i.e. an area of ​​approximately 2.5 cm2, and the ceramics of the transducer have for example a diameter slightly smaller than that of the sonotrode.

[0793] The sonotrode is for example contained in a casing, with its front end protruding from the casing by several centimeters, preferably less than 5 cm.

[0794] Tests are carried out by varying different parameters, namely: - the total concentration of surfactant(s) (%) in the composition, - the peak acoustic intensity I (in W / cm2), which depends directly on the activation voltage U - the pulse duration - the duty cycle, Ton / Toff - the duration during which the surface to be cleaned is subjected to acoustic waves, - the distance between the emitting surface and the surface to be cleaned.

[0795] The acoustic intensity Lata on the surface to be cleaned, expressed in W / cm2, is calculated according to the selected parameters. It is given by: "'""l ISATA = I^

[0797] The acoustic intensity Lata can also be expressed as a function of the average acoustic pressure Pm applied to the treated area:

[0798] T _ Pi lSATA~ pc

[0799] With P the density of the composition (in kg.m-3), c the speed of sound in the composition (in ms-1), Pm the average acoustic pressure (in Pa, or equivalently in Nm-2 or kg.ml.s-2), and Isata in W.mA

[0800] The effectiveness of the combination of parameters for each test is evaluated on the basis of a percentage of makeup removal (% makeup removal) calculated from gradients measured on a colorimetric scale (delta E).

[0801] Cleaning is considered to have a satisfactory effect for a delta E greater than or equal to 15, and a makeup removal percentage greater than 65%.

[0802] [Tables 1] Surfactant (%) Intensity I (W / cm2) Ton Duty cycle Ton / Toff Duration (s) Isata (W / cm2) % makeup removal Delta E 0.5 6.8 0.05 58.33 3 3.96 66.6 16.15 0.5 7.2 0.02 66.66 4 4.78 81.9 18.54 0.5 6.2 0.08 66.66 4 4.13 86.1 16.97 0.8 6.8 0.04 56 3 3.66 86.3 18 1 6.8 0.05 50 3 3.40 72.5 15.07 1 6.8 0.05 58.33 3 3.96 74.9 16.27 1 6.8 0.05 58.33 2 3.96 77.8 15.92 1 6.8 0.05 58.33 3 3.96 78.7 18.15 1 6.8 0.05 58.33 3 3.96 79.3 17.29 1 6.8 0.05 62 3 4.21 81 17.51 ​​1 6.8 0.05 58.33 3 3.96 84.5 16.72 1 7.0 0.05 58.33 3 4.18 88.4 17.8 1 6.8 0.05 58.33 4 3.96 90.4 19.98 1 6.8 0.02 58.33 3 3.96 91.5 18.09 1.2 6.8 0.04 56 3 3.80 75.6 16.21 1.5 6.2 0.08 50 4 3.10 79.8 19.36 1.5 6.2 0.02 66.66 4 4.13 89.7 18.46

[0803] For the parameter combinations summarized in the table above, there is a strong removal of the foundation in the regions where the sonotrode passes while being active.

[0804] Furthermore, it is noted that it is very difficult to remove makeup simply by passing a sponge or brush over it, which highlights the cleaning effect obtained in the invention. Response surfaces

[0805] The parameter values ​​obtained experimentally above, and demonstrating good makeup removal efficiency, can be extended to parameter ranges using an optimization plan taking into account the different interactions between all the parameters.

[0806] Response surfaces are thus obtained, as illustrated in Figures 40 to 45, illustrating ranges of values ​​of the different parameters for which satisfactory makeup removal efficiency is found.

[0807] The makeup removal efficiency is considered satisfactory according to the same criteria as stated above, i.e. for a delta E greater than or equal to 15, and a makeup removal percentage greater than 65%.

[0808] In the optimization plan, three parameters are fixed, namely: - the total concentration of surfactant(s) (%) in the composition, - the peak acoustic intensity I (in W / cm2), and - the duration during which the surface to be cleaned is subjected to acoustic waves.

[0809] Optimal value ranges are determined for the other two parameters, namely, the pulse duration Ton and the duty cycle Ton / Toff.

[0810] The optimal value ranges are defined as those meeting the aforementioned makeup removal criteria. On the illustrated response curves, this corresponds to the areas located beyond the 0 isobar.

[0811] These ranges of values ​​are summarized in the table below, with reference to each of the figures illustrating the corresponding response surface.

[0812] For certain parameter values, as for example shown on the response surface of [Fig.45e], the response surface shows that there is no pulse duration and Ton / Toff duty cycle value meeting the aforementioned makeup removal efficiency criteria.

[0813] For other parameter values, as for example shown in Figures 40b to 40e, the entire domain considered for optimization meets the criteria for makeup removal efficiency.

[0814] [Tables2] Duration (s) I (W / cm2) Surfactant (%) Tone (s) Duty cycle (%) Response surface 4 6.2 0.5 [0.025 ; 0.080] [50 ; 66.66] Figure 40a [0.020 ; 0.080] [52 ; 65] [0.8 ; 1.5] [0.020 ; 0.080] [50 ; 66.66] Figure 40b [0.020 ; 0.080] [50 ; 66.66] Figure 40c [0.020 ; 0.080] [50 ; 66.66] Figure 40d [0.020 ; 0.080] [50 ; 66.66] Figure 40e 4 6.8 0.5 [0.027; 0.080] [50; 66.66] Figure 41a [0.020; 0.080] [52; 66.66] 0.8 [0.030; 0.080] [50; 66.66] Figure 41b [0.020; 0.080] [52; 66.66] 1.0 [0.035; 0.080] [50; 66.66] Figure 41c [0.020; 0.080] [52.5; 66.66] 1.2 [0.020; 0.080] [54; 66.66] Figure 41d [0.035; 0.080] [51.5; 66.66] 1.5 [0.020; 0.080] [57.5; 66.66] Figure 41e [0.038; 0.080] [54; 66.66] 4 7.2 0.5 [0.020 ; 0.080] [50 ; 66.66] Figure 42a 0.8 [0.020 ; 0.080] [50 ; 66.66] Figure 42b [0.030 ; 0.070] [52 ; 66.66] 1.0 [0.020 ; 0.080] [50 ; 66.66] Figure 42c [0.030 ; 0.070] [52.5 ; 66.66] 1.2 [0.020 ; 0.080] [54 ; 66.66] Figure 42d [0.025 ; 0.070] [51.5 ; 66.66] 1.5 [0.028 ; 0.045] [57.5 ; 66.66] Figure 42e 3 6.2 0.5 [0.070 ; 0.080] [54 ; 60.5] Figure 43a [0.055 ; 0.0775] [56 ; 62] 0.8 [0.020 ; 0.080] [56 ; 66.66] Figure 43b [0.040 ; 0.080] [51 ; 66.66] 1.0 [0.020 ; 0.080] [54 ; 66.66] Figure 43c [0.035 ; 0.080] [51.5 ; 66.66] 1.2 [0.020 ; 0.080] [54 ; 66.66] Figure 43d [0.040 ; 0.080] [51.5 ; 66.66] 1.5 [0.020 ; 0.080] [57 ; 66.66] Figure 43e [0.035 ; 0.080] [55 ; 66.66] 3 6.8 0.5 [0.020 ; 0.065] [56 ; 66,66] Figure 44a [0.035 ; 0.075] [53,5 ; 64] 0.8 [0.020 ; 0.080] [55 ; 64,5] Figure 44b [0.030 ; 0.072] [53 ; 66,66] 1.0 [0.032 ; 0.070] [54 ; 66,66] Figure 44c [0.020 ; 0.080] [56 ; 64,5] 1.2 [0.032 ; 0.070] [55,5 ; 66,66] Figure 44d [0.020 ; 0.080] [58 ; 64] 1.5 [0.025 ; 0.063] [61,5 ; 66,66] Figure 44e [0.030 ; 0.058] [60 ; 66,66] 0.5 [0.020 ; 0.080] [57 ; 65] Figure 45a 3 7.2 [0.030 ; 0.065] [55 ; 66,66] 0.8 [0.020 ; 0.080] [58 ; 66,66] Figure 45b [0.020 ; 0.068] [55 ; 66,66] 1.0 [0.020 ; 0.0725] [58,5 ; 66,66] Figure 45c [0.020 ; 0.0575] [56 ; 66,66] 1.2 [0.020 ; 0.060] [61 ; 66,66] Figure 45d [0.020 ; 0.046] [58,5 ; 66,66] 1.5 - - Figure 45e - -

Claims

Claims

1. Device for treating keratin materials (K) in contact with a fluid (C), in particular a cosmetic composition, the device comprising: - At least one ultrasonic transducer (4) having an emission surface (S) of acoustic waves in said fluid to generate therein bubbles having a mechanical action when they collapse on said keratin materials, the emission surface having reliefs (420) where the bubbles can originate at different levels along the longitudinal axis (X) of the transducer, - a vibrator (750) to subject at least part of the emission surface to additional vibrations, of a frequency lower than that of the acoustic waves.

2. Device according to the preceding claim, the transducer (4) comprising a sonotrode, and the reliefs (420) being monolithic with the sonotrode.

3. Device according to claim 1, the transducer comprising a sonotrode, and the reliefs being formed on at least one part (95) attached to the sonotrode, in particular held thereon by a removable attachment.

4. Device according to claim 3, the insert being made of a material different from that of the sonotrode, in particular a harder material.

5. Device according to any one of the preceding claims, the reliefs being arranged in a regular arrangement, in particular in a regular network in both dimensions.

6. Device according to any one of the preceding claims, the reliefs being identical, in particular in the form of an elementary pattern which is repeated in two directions perpendicular to each other, this pattern preferably having a prismatic shape, in particular pyramidal, or other, in particular hemispherical, cylindrical, semi-cylindrical or ogival.

7. Device according to any one of the preceding claims, the surface for emitting the acoustic waves comprising at least one relief having a non-regular pyramidal, truncated, cylindrical, hemispherical or prismatic shape, in particular a regular network of four-sided pyramidal reliefs.

8. Device according to any one of claims 1 to 4, the reliefs being in the form of ribs or grooves.

9. Device according to any one of claims 1 to 4, all or part of the reliefs having a distribution on the emission surface and / or a random size.

10. Device according to any one of the preceding claims, the emission surface having reliefs having a height, measured parallel to the longitudinal axis of the sonotrode, of between 0.001 mm and 50 mm, better still 0.01 mm and 30 mm, even better still between 0.1 and 1 mm.

11. Device according to any one of the preceding claims, in which when the emission surface is observed in the longitudinal axis of the sonotrode, the largest dimension (h) of the reliefs is between 0.001 mm and 100 mm, better between 0.1 and 1 mm.

12. Device according to any one of the preceding claims, in which the reliefs are formed by the presence of successive patterns in one or two directions, the size of the patterns and the distance between consecutive patterns being chosen such that the pattern density is between 1 and 106 patterns / cm2.

13. Device according to any one of the preceding claims, the emission surface having, in addition to the reliefs which contribute to improving the production of bubbles, reliefs which pursue another purpose, in particular to exert an action of retaining the fluid or cleaning the area to be treated, in particular reliefs made of a flexible material, in particular bristles, preferably flocking bristles.

14. Device according to any one of the preceding claims, the vibrator comprising a motor (751) driving an unbalanced mass (752) in rotation.

15. Device according to any one of the preceding claims, the additional vibrations being of frequency less than or equal to 1500 Hz, better still less than or equal to 150 Hz, in particular 50 Hz.

16. Device according to any one of the preceding claims, the emission surface being subjected by the vibrator to additional transverse and / or longitudinal and / or angular, preferably longitudinal, vibrations.

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