WO2024188639A1 - Process for curling keratin fibres with application of an aqueous composition comprising cysteine and/or a salt thereof and heating of said fibres - Google Patents

Abstract

The present invention relates to a process for treating keratin fibres, in particular the eyelashes, comprising: 1) the application of a composition comprising, in particular in a physiologically acceptable medium: a) at least 40.0% by weight of water relative to the total weight of the composition; and b) cysteine and/or a salt thereof, said composition having a pH of greater than 8.5; and 2) heating of the keratin fibres to a temperature of greater than or equal to 45 °C, the heating of the keratin fibres being carried out during or after the application of said composition; said process not comprising an step of oxidation with an oxidizing agent other than air.

Description

Process for curling keratin fibres with application of an aqueous composition comprising cysteine and/or a salt thereof and heating of said fibres

The present application relates to the field of coating keratin fibres, in particular the eyelashes.

In products for making up keratin surfaces such as the lower and/or upper eyelids, for instance mascaras, consumers normally look for curl, sheen, colour intensity and good wear properties, in particular water resistance.

In general, compositions dedicated to making up keratin fibres, such as the eyelashes, are targeted at densifying the thickness and the visual perception of the eyelashes or eyebrows and ultimately the look. However, another property very particularly desired by consumers is that of obtaining in a significant way a curling of said keratin fibres which is persistent to successive makeup removal operations. Water-resistant anhydrous mascaras do not make it possible to maintain the curvature of the eyelashes after several makeup removal operations.

In the salon, professionals use a makeup process inspired by techniques for the permanent waving of the hair which consists, in a first step, in putting the eyelashes in the desired shape with a suitable support, in applying, to the eyelashes, a reducing composition comprising a reducing agent (for example, ammonium thioglycolate and its derivatives, thiol compounds) which breaks the disulfide bridges of the keratin of the eyelashes and then, in a second step, in applying an oxidizing composition comprising at least one oxidizing agent, such as hydrogen peroxide, in order to re-establish the disulfide bridges of the keratin of the eyelashes, and obtain long-lasting curling. This process exhibits the disadvantages of being restricting, expensive, uncomfortable and not giving the consumer the possibility of easily carrying out this procedure herself at home.

The patent applications KR101823336 and KR101823401 have provided a process for the semipermanent curling of the eyelashes comprising the application, to the eyelashes, of a mascara comprising at least one reducing agent, such as cysteine, cysteamine, thiol compounds, sodium bisulfite, sodium metabisulfite, sodium hydrosulfite or superoxide dismutase, and at least one antioxidant, such as a compound based on phosphoric acid or a compound based on zinc, on gold, on tin or on silver, followed by washing and drying the eyelashes thus treated. This technique for the semipermanent curling of the eyelashes is not entirely satisfactory with regard to the significant curvature effect obtained and with regard to the persistence of the effect after a makeup removal operation.

Published patent application FR3114501A1 discloses a process for coating, and more particularly for curling, the eyelashes or the eyebrows, comprising
- at least a first step of applying a first reducing composition (A) comprising, preferably in a physiologically acceptable medium, at least 40.0% by weight of water relative to the total weight of the composition and at least 1.0% by weight of cysteine and/or a salt thereof relative to the total weight of the composition, said composition having a pH of greater than 8.0 and successively
- at least a second step of applying to said fibres treated with the composition (A) at least a second composition (B) preferably comprising, in a physiologically acceptable medium:
i) an aqueous phase; and
ii) a fatty phase comprising at least one wax; and
iii) at least one anionic surfactant comprising at least one cationic counterion, said anionic surfactant preferably being in a form neutralized by said counterion; and
iv) optionally at least one aqueous dispersion of film-forming polymer particles. Consumers can feel that this two-step gesture for curling the eyelashes is restricting.

There is therefore still a need to find a new simplified process for treating keratin fibres, in particular the eyelashes, and in particular for curling the eyelashes, which is easier, owing to the gesture involved, for consumers to implement at home and produces an effective curling of said fibres that is persistent, without the constraints of the known processes of the prior art mentioned above, such as the use of an oxidizing agent other than air and/or of a shaping support during the reduction step.

Unexpectedly, the inventors have found that it is possible to achieve these performances with a process for curling the eyelashes, comprising
1) the application of a composition comprising, in particular in a physiologically acceptable medium:
a) at least 40.0% by weight of water relative to the total weight of the composition; and
b) cysteine and/or a salt thereof; said composition having a pH of greater than 8.5; and
2) heating of the eyelashes to a temperature of greater than or equal to 45°C; said heating of the eyelashes being carried out during or after the application of said composition; said process not comprising a step of oxidation with an oxidizing agent other than air;
the heating step being carried out during the step of reducing the eyelashes with the composition, for a time ranging from 30 seconds to 45 minutes, and the heating being carried out at a temperature of from 45 to 65°C.

This discovery forms the basis of the invention.

Subjects of the invention

Thus, a first subject of the present invention is a process for curling the eyelashes, comprising
1) the application of a composition comprising, in particular in a physiologically acceptable medium:
a) at least 40.0% by weight of water relative to the total weight of the composition; and
b) cysteine and/or a salt thereof; said composition having a pH of greater than 8.5; and
2) the use of heating of the eyelashes to a temperature of greater than or equal to 45°C; said heating of the eyelashes being carried out during or after the application of said composition; said process not comprising a step of oxidation with an oxidizing agent other than air;
the heating step being carried out during the step of reducing the eyelashes with the composition, for a time ranging from 30 seconds to 45 minutes, and the heating being carried out at a temperature of from 45 to 65°C.

A second subject of the present invention is an assembly or kit for curling the eyelashes, comprising:
i) a composition as defined above and
ii) a means for heating the eyelashes to a temperature of greater than or equal to 45°C.

Definitions

In the context of the present invention, the term “keratin fibres” is understood to mean the eyelashes. For the purposes of the present invention, this term “keratin fibres” also extends to false eyelashes.

The term "physiologically acceptable" is understood to mean compatible with keratin fibres, in particular the eyelashes, and the skin around the eyes, which has a pleasant colour, odour and feel and which does not cause any unacceptable discomfort (stinging or tautness) liable to discourage the consumer from using this composition.

Cysteine

According to the present invention, the composition comprises cysteine and/or a salt thereof relative to the total weight of the composition.

Mention may more particularly be made, among the cosmetically acceptable salts of cysteine, of the hydrochlorides, hydrobromides, citrates, acetates and sulfates.

Preferably, the cysteine employed can be chosen from L-cysteine, D-cysteine or L,D-cysteine. L-cysteine or a salt thereof will more particularly be used.

The cysteine and/or one of the salts is (are) preferably present in the composition of the invention in a content of at least 0.5% by weight, more preferentially ranging from 1 to 20% by weight, and more particularly ranging from 8 to 15%, relative to the total weight of the composition.

Aqueous phase

The composition according to the invention comprises at least 40.0% by weight of water relative to the total weight of the composition and has a pH of greater than 8.5.

The pH of the composition according to the invention preferably ranges from 9 to 10.0.

The pH may be obtained and/or adjusted conventionally by adding at least one alkaline agent and/or at least one acidifying agent and/or at least one buffering agent.

The alkaline agent may be chosen from an organic base such as aqueous ammonia, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-amino-2-methyl-1-propanol, 1,3-propanediamine, an alkali metal carbonate or bicarbonate or ammonium carbonate or bicarbonate, for example sodium bicarbonate, or an organic carbonate such as guanidine carbonate.

According to one particular form, the organic alkaline agent is monoethanolamine.

The alkaline agent may be chosen from an inorganic base, for instance an alkali metal hydroxide such as sodium hydroxide (caustic soda) or potassium hydroxide (caustic potash), it being possible, of course, for all these compounds to be taken alone or as a mixture.

The acidifying agent may be chosen from hydrochloric acid, acetic acid, lactic acid, boric acid, citric acid and phosphoric acid.

The buffering agent may be a phosphate buffer or a carbonate buffer.

Preferably, the inorganic base is sodium hydroxide (caustic soda)

The amount of water is at least 40.0% by weight relative to the total weight of the composition. Preferentially, it ranges from 50 to 92% by weight, and more preferentially from 60 to 90% by weight, relative to the total weight of the composition.

The water can be demineralized, or also a floral water, such as cornflower water, and/or a mineral water, such as Vittel water, Lucas water or La Roche Posay water, and/or a thermal water.

Cosmetic additives

The composition of the invention may contain conventional cosmetic additives such as hydrophilic gelling agents, surfactants, preservatives, fragrances, antioxidants, moisturizing agents such as polyols, for instance 1,3-propanediol, glycerol, pentylene glycol, caprylyl glycol, propylene glycol, ethylene glycol, 1,3-butylene glycol, dipropylene glycol, C₂-C₈ monoalcohols such as ethanol or isopropanol.

Of course, a person skilled in the art will take care to choose the optional additional additives and/or their amount such that the advantageous properties of the composition according to the invention are not, or not substantially, detrimentally affected by the envisaged addition.

Hydrophilic gelling agent

According to a particular form of the invention, the composition according to the invention also comprises one or more hydrophilic gelling agent(s).

For the purposes of the present invention, the term “hydrophilic gelling agent” means a compound that is capable of gelling the aqueous phase of the compositions according to the invention. More particularly, the function of these hydrophilic gelling agents is to structure the aqueous phase of the composition. The gelling agent is advantageously soluble in the aqueous phase of the composition. The gelling agent that may be used according to the invention may notably be characterized by its ability to form, in water, beyond a certain concentration C*, a gel characterized by oscillatory rheology (µ = 1 Hz) by a yield point τc at least equal to 10 Pa. This concentration C* can vary widely depending on the nature of the gelling agent under consideration.

The hydrophilic gelling agents are preferably chosen from non-ionic polysaccharides.

Non-ionic polysaccharides are carbohydrate macromolecules formed by the linking of a large number of hydrophilic elementary sugars (monosaccharides) bonded together via O-oside bonds.

They may be chosen from native polysaccharides, modified polysaccharides, and mixtures thereof.

The term “modified polysaccharide” means any chemically or enzymatically modified polysaccharide including at least one functional group.

The functional groups may be hydrocarbon-based groups (constituted essentially of carbon and hydrogen atoms) such as alkyl, alkenyl, aryl (i.e. phenyl) or aralkyl (i.e. benzyl) groups. The hydrocarbon-based groups may be unsubstituted, for example constituted of a simple alkyl chain or substituted with groups such as aromatic groups such as aryl (i.e. phenyl) or aralkyl (i.e. benzyl) groups or alternatively polar groups, for instance hydroxyl groups.

The optionally modified non-ionic polysaccharides that are suitable for use in the invention may be homopolysaccharides such as fructans, glucans, galactans and mannans or heteropolysaccharides such as hemicellulose. They may be starchy polysaccharides such as native or modified starches. The non-starchy polysaccharides may be chosen from polysaccharides produced by microorganisms; polysaccharides isolated from algae, and higher plant polysaccharides, such as homogeneous polysaccharides, in particular celluloses and derivatives thereof or fructoses, heterogeneous polysaccharides such as galactomannans, glucomannans and pectins, and derivatives thereof; and mixtures thereof. In particular, the polysaccharides may be chosen from fructans, glucans, amylose, amylopectin, glycogen, pullulan, dextrans, celluloses and derivatives thereof, in particular methylcelluloses, hydroxyalkylcelluloses and ethylhydroxyethylcelluloses, cetylhydroxyethylcelluloses, mannans, xylans, arabans, galactans, galacturonans, chitin, chitosans, glucuronoxylans, arabinoxylans, xyloglucans, glucomannans, arabinogalactans, agars, karaya gums (about 40% acid), locust bean gums, guar gums and non-ionic derivatives thereof, in particular hydroxypropyl guar, and biopolysaccharide gums of microbial origin, in particular scleroglucan gums. They are notably chosen from celluloses such as cetylhydroxyethylcelluloses; guar gums that are notably modified such as hydroxypropyl guars, agarose; pullulans, inulins and starches.

Preferably, use will be made of cellulose compounds, in particular hydroxyethylcellulose.

The hydrophilic gelling agent(s) are preferably present in the composition in a total content ranging from 0.1 to 10%, better still from 0.5 to 5% by weight, relative to the total weight of said composition.

Surfactants

According to a particular form of the invention, the composition according to the invention additionally comprises one or more surfactant(s) with an HLB of greater than or equal to 8.0.

For the purposes of the present invention, the term “surfactant” is understood to mean an amphiphilic chemical compound, that is to say a compound exhibiting, in its structure, two parts of different polarity. Generally, one is lipophilic (soluble or dispersible in an oily phase). The other is hydrophilic (soluble or dispersible in water). Surfactants are characterized by the value of their HLB (hydrophilic-lipophilic balance), the HLB being the ratio of the hydrophilic part to the lipophilic part in the molecule. The term “HLB” is well known to a person skilled in the art and is described, for example, in “The HLB System. A Time-Saving Guide to Emulsifier Selection” (published by ICI Americas Inc.; 1984). The HLB of the surfactant(s) used according to the invention can be determined by the Griffin method.

The surfactants with an HLB of greater than or equal to 8.0 may be chosen from anionic surfactants, non-ionic surfactants and mixtures thereof.

The term “anionic surfactant” is understood to mean any negatively charged amphiphilic molecule.

The term “non-ionic surfactant” is understood to mean any amphiphilic molecule that is neutral, that is to say not negatively or positively charged.

According to a preferred embodiment of the invention, the surfactant(s) with an HLB of greater than or equal to 8.0 is (are) present in a content ranging from 3.5 to 20.0% by weight, more preferentially from 4.0 to 20.0% by weight, better still from 4.5% to 15.0% by weight, and even better still from 5.0 to 15.0% by weight, relative to the total weight of the composition.

a) Anionic surfactants

The anionic surfactant(s) with an HLB of greater than or equal to 8.0 in accordance with the invention is (are) preferably chosen from:
i. mono(C₁₂-C₂₀)alkyl phosphates;
ii. alkyl sulfates, and in particular alkyl ether sulfates, alkyl amidoether sulfates; iii. alkylaryl polyether sulfates, monoglyceride sulfates;
iv. alkyl sulfonates, alkylamide sulfonates, alkylaryl sulfonates, α-olefin sulfonates, paraffin sulfonates;
v. alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates; alkyl sulfosuccinamates;
vi. acyl sarcosinates, acyl glutamates, acyl isethionates, N-acyl taurates, acyl lactylates;
vii. fatty acids having from 14 to less than 20 carbon atoms;
viii. mixtures thereof.

Use will more particularly be made of alkyl sulfates such as that having the INCI name: Ammonium Lauryl Sulfate, such as the commercial product Empicol AL 30/FL3® sold by Innospec Active Chemicals.

b) Non-ionic surfactants

The non-ionic surfactant(s) with an HLB of greater than or equal to 8.0 in accordance with the invention is (are) preferably chosen from polyoxyalkylenated, monoglycerolated and/or polyglycerolated surfactants.

For the purposes of the present invention, a “polyoxyalkylenated compound” is understood to mean any molecule comprising in its chemical structure at least one chain comprising oxyalkylene units, in particular -(OCH₂CH₂)_n oxyethylene and/or -(OCH₂CH₂CH₂)_p oxypropylene units.

For the purposes of the present invention, a “monoglycerolated or polyglycerolated compound” is understood to mean any molecule comprising in its chemical structure a glycerol group or a chain comprising -(O-CH₂-CHOH-CH₂OH)_m glycerol units.

According to one particular embodiment of the invention, the non-ionic surfactant(s) with an HLB value at 25°C of greater than or equal to 8 correspond to formula (I) below:
[Chem 1]
(ALK-[C(O)]_a-[O]_b)_c-X (I)
in which:
- ALK is a C₇-C₂₃, preferably C₁₁-C₂₁, more preferentially C₁₅-C₁₇, alkyl group,
- a and b are integers ranging from 0 to 100,
- c is an integer ranging from 1 to 100, in particular from 1 to 3, preferably equal to 1, a and b preferably being equal to 0,
- X is an optionally hydroxy-substituted and/or hydroxy-terminated (poly)oxyalkylene group, X preferably being an oxyethylene group -(CH₂CH₂O)_n or
-(OCH₂CH₂)_n in which n is an integer greater than or equal to 1, for example ranging
from 1 to 200, said (poly)oxyalkylene group preferably being a polyethylene glycol or being the result of at least one substitution of a hydroxyl group, preferably chosen from (poly)glycerols.

The group X is preferably chosen from
i) those of formula (II) below:
[Chem 2]
HO-(ALK-O)_z-CH₂-CH[(OALK)_y-OH]-CH₂-(O-ALK)_x-(*) (II)
in which:
- ALK, which may be identical or different, represents a C₁-C₆, in particular C₁-C₄, alkylene group, preferably ethylene,
- x, y, z is an integer between 0 and 200, it being understood that x+y+z is other than 0, x+y+z preferably being between 1 and 150 inclusive, in particular between 20 and 60 inclusive;
ii) those of formula (III) or (IV) below:
[Chem 3]
H-(ALK-O)_x-(*) (III)
or
[Chem 4]
H-(O-ALK)x-(*) (IV)
in which:
- ALK, which may be identical or different, represents a C₁-C₆, in particular C₁-C₄, alkylene group, preferably ethylene,
- x is an integer other than 0 and preferably between 1 and 200.

Preferably, X is an H-(O-ALK)_x-(*) group.

The non-ionic surfactant(s) with an HLB value at 25°C of greater than or equal to 8, preferably greater than or equal to 10, is (are) chosen from:
- polyoxyalkylenated, in particular oxypropylenated and optionally oxyethylenated, glycerol ethers which may contain from 20 to 200 oxyalkylene units, such as PPG-50 glyceryl ether sold under the trade name Newpol GP-3000® and PPG-67 glyceryl ether sold under the trade name Newpol GP-4000® by Sanyo Chemical; PPG-24-glycereth-24 sold under the trade name Nikkol SG-G2424® by Nikko Chemicals;
- polyoxyalkylenated, in particular polyoxyethylenated and/or polyoxypropylenated, alcohols which may comprise from 20 to 200 oxyethylene and/or oxypropylene units, preferably from 20 to 100 oxyethylene units, in particular polyethoxylated fatty alcohols, which are in particular C₈-C₂₄, and preferably C₁₂-C₁₈, such as Steareth-20, for instance the product BRIJ 78® sold by Croda, Ceteareth-30, such as the product Eumulgin B 3® sold by BASF, Oleth-30, such as the product Eumulgin O 30® sold by BASF;
-polyoxyalkylenated fatty acid esters, in particular esters of notably a C₈-C₂₄ and preferably C₁₆-C₂₂ fatty acid and of polyethylene glycol (or PEG) which may comprise from 20 to 200 oxyethylene units, such as PEG-50 stearate sold under the trade name Myrj S50® and PEG-40 stearate sold under the name Myrj S40® by Croda;
- esters of a notably C₈-C₂₄ and preferably C₁₆-C₂₂ fatty acid and of (poly)oxyalkylenated, in particular oxyethylenated and/or oxypropylenated, glycerol ethers, which may contain from 20 to 200 oxyethylene and/or oxypropylene units, such as PEG-200 glyceryl stearate sold under the name Simulsol 220® by SEPPIC; PEG-30 glyceryl stearate such as the product Tagat S® sold by Evonik, PEG-20 glyceryl oleate such as the product Tagat O2V® sold by Evonik, PEG-20 glyceryl laurate such as the product Tagat L2® from Evonik;

- fatty acid esters, in particular C₈-C₂₄ and preferably C₁₆-C₂₂ fatty acid esters;

- (poly)oxyalkylenated, in particular oxyethylenated and/or oxypropylenated, sorbitol ethers, which may comprise from 20 to 200 oxyethylene and/or oxypropylene units, such as Polysorbate-20 sold under the name Tween 20®, Polysorbate-21 sold under the name Tween 21®, Polysorbate-40 sold under the name Tween 40®, Polysorbate-60 sold under the name Tween 60® and Polysorbate-80 sold under the name Tween-80-LQ® by Croda;

- esters of a C₁₂-C₂₀ fatty acid and of a polyglycerol comprising from 3 to 12 glycerol groups, preferably from 6 to 10 glycerol groups, such as
Polyglyceryl-6 stearate, for instance the product sold under the name Nikkol Hexaglyn 1-SV® by Nikko Chemicals; Polyglyceryl-6 Isostearate sold under the name Plurol Isostearique® by Gattefosse; Polyglyceryl-10 stearate, such as the product sold under the name Nikkol Decaglyn 1-SVEX® and Polyglyceryl-10 isostearate such as the product sold under the name Nikkol Decaglyn 1-ISV® by Nikko Chemicals, Polyglyceryl-10 Laurate, such as the product sold under the name Dermofeel G 10 L® by Dr Straetmans, Polyglyceryl-10 myristate, such as the commercial product Nikkol Decaglyn 1-M® sold by Nikko Chemicals, Polyglyceryl-10, such as the commercial product Nikkol Decaglyn 1-OV® sold by Nikko Chemicals;

- and a mixture or mixtures thereof.

Use will more particularly made of a polyoxyalkylenated alcohol, more particularly Oleth-30, such as the product sold under the name Eumulgin O 30® by BASF.

According to a particular embodiment, the composition of the invention comprises a mixture of at least one anionic surfactant with an HLB ≥ 8.0 of the alkyl sulfate type and at least one non-ionic surfactant with an HLB ≥ 8.0 of the polyoxyalkylenated alcohol type, in particular a mixture of ammonium lauryl sulfate and oleth-30.

Fatty alcohol

Preferentially, the compositions according to the invention also comprise at least one fatty alcohol. A composition can therefore comprise a single fatty alcohol according to the invention or several distinct fatty alcohols.

If several distinct fatty alcohols are present, they can be added separately during the preparation of the composition and the mixture thereof can then be formed in situ. They can also be used in the form of a mixture which is already commercially available and in which the weight proportion and the degree of purity of each of the fatty alcohols are controlled. In other words, the composition of these mixtures is faithfully reproducible, as opposed to mixtures of fatty alcohols generated via synthesis from starting materials derived from complex mixtures.

The fatty alcohol(s) is (are) in particular chosen from linear or branched, saturated or unsaturated C₁₄-C₃₀, preferably C₁₄-C₂₄, and even better still C₁₄-C₂₀, fatty alcohols.

The fatty alcohol(s) is (are) in particular chosen from linear and saturated C₁₄-C₃₀ fatty alcohols, preferably linear and saturated C₁₄-C₂₄ fatty alcohols, and better still linear and saturated C₁₄-C₂₀ fatty alcohols.

According to a particularly preferred embodiment, the fatty alcohol is in the form of a mixture of several different fatty alcohols, and is preferably a mixture of several linear and saturated C₁₄-C₃₀, better still C₁₄-C₂₄, even better still C₁₄-C₂₀, fatty alcohols.

Preferably, the fatty alcohol according to the invention is chosen from cetyl alcohol (C16), stearyl alcohol (C18) and mixtures thereof (also known as cetearyl alcohol). Preferentially, the fatty alcohol according to the invention is a mixture of cetyl alcohol and stearyl alcohol. Such a mixture is notably sold under the name Lannette O OR/MB® by BASF.

According to a preferred embodiment, the fatty alcohol is solid at ambient temperature.

The fatty alcohol is present in the compositions of the invention in amounts ranging from 1.0 to 20.0% by weight, relative to the total weight of the composition, preferably from 2.0 to 15.0% by weight and even more particularly from 3.0 to 10.0% by weight, relative to the total weight of the composition.

Cosmetic applications

The composition used according to the invention may be a composition for caring for and/or treating keratin fibres, such as the eyelashes.

More especially, the composition according to the invention is a curling product for the eyelashes, such as a mascara.

The aqueous composition of the invention may be in the form of a gel or a cream.

Such compositions are in particular prepared according to the general knowledge of a person skilled in the art.

Eyelash heating means

1. Conduction heating

According to a particular embodiment, the composition in accordance with the invention may be subjected to conduction heating means during or after application of said composition.

These conduction heating means may be integral with an assembly or kit for treating keratin fibres, and more particularly with an applicator configured to apply said cosmetic composition for treating keratin fibres, and optionally, if needed, with a packaging device suitable for receiving said composition.

The heating means may also come into contact with or face the composition to be heated.

The composition may be heated while it is contained in a packaging device.

The composition may be locally heated to a temperature greater than or equal to 45°C, or even greater than or equal to 50°C, or even greater than or equal to 55°C. The temperature of the composition should not entail any risk of burning at the time of application. In particular, the temperature in the vicinity of the eye must not exceed 60°C. For this reason, when the composition is heated before application, a waiting time between the moment when the composition is heated and the application to the keratin fibres may optionally be necessary.

According to one embodiment variant, the composition is heated simultaneously with its application to the keratin fibres.

According to another variant, the composition is heated after its application to the keratin fibres.

The temperature may be from 55°C to 65°C inclusive.

The temperature may be measured, for example, at the surface using an infrared pyrometer, for example a Fluke® brand machine.

Among these conduction heating means, mention may be made of the heating mascaras described in patents EP1466541B1, FR2865912B1, FR2869818B1, FR2946236B1, EP2445370B1, FR2947703B1, FR2996767B1 and FR3039379B1.

As other conduction heating means, mention may also be made of heating eyelash curlers which are brought into contact with the keratin fibres, in particular the eyelashes, by means of a heating brush or comb, such as the device sold under the trade name Grande Lash-Lift® by Sephora, Luxy Curl® from Lux, Heated Eyelash Curler from Ardell or Touch Beauty. These can be applied to the eyelashes after the application of the composition comprising cysteine and/or a salt thereof. The temperature will be adjusted to the type of the eyelashes to be treated.

1. Air-convection heating

According to one particular embodiment, the keratin fibres may be heated by an air-convection heating means during or after the application of the composition based on cysteine and/or a salt thereof.

The air-convection heating means may be a hair dryer. The minimum temperature of this type of device is generally 50°C. Care will preferably be taken to use this type of device with the eyes closed and at a good distance from the eye while not exceeding the temperature of 60°C.

1. Infrared -radiation heating

According to one particular embodiment, the keratin fibres may be heated by an infrared-radiation heating means during or after the application of the composition based on cysteine and/or a salt thereof.

Mention may be made, for example, of the Sanitas SIL 06©, IL11®, IL21® and IL35® infrared lamps from Beurer.

Process for curling keratin fibres

A subject of the present application is a process for curling the eyelashes, comprising:
1) the application of a composition comprising, in particular in a physiologically acceptable medium:
a) at least 40.0% by weight of water relative to the total weight of the composition; and
b) cysteine and/or a salt thereof; said composition having a pH of greater than 8.5; and
2) heating of the eyelashes to a temperature of greater than or equal to 45°C; it being possible for said heating of the eyelashes to be carried out during or after the application of the composition;
said process not comprising a step of oxidation with an oxidizing agent other than air;
the heating step being carried out during the step of reducing the eyelashes with the composition, for a time ranging from 30 seconds to 45 minutes, and the heating being carried out at a temperature of from 45 to 65°C.

According to a particular embodiment of said process, the application of the aqueous composition based on cysteine and/or a salt thereof is followed by a period in which said composition is left on the treated keratin fibres for a time ranging from 5 to 45 minutes. Preferentially, after said leave-on period, the keratin fibres are cleansed and then dried.

The step of cleansing the keratin fibres can be carried out at ambient temperature (25°C) with cotton wool soaked with a two-phase makeup remover such as the commercial product Respectissime® from La Roche Posay or a micellar water such as Garnier's commercial product Solution Micellaire Tout-en-un® .

The step of drying the keratin fibres may be carried out, for example, by means of dry cotton wool at ambient temperature (25°C).

According to the process for curling the eyelashes according to the invention, the heating step is carried out during the step of reducing the eyelashes with the composition based on cysteine and/or a salt thereof, for a time ranging from 30 seconds to 45 minutes and the heating is done at a temperature of from 45 to 65°C.

Packaging and application assembly or kit

The present invention also relates to an assembly or kit for treating the eyelashes, in particular an assembly or kit for curling the eyelashes, comprising:
i) a composition as defined above, and
ii) a means for heating the eyelashes to a temperature of greater than or equal to 45°C.

According to one particular embodiment, the assembly or kit for treating the eyelashes, in particular the assembly or kit for curling the eyelashes, comprises:
- a packaging device comprising said cosmetic composition for coating the eyelashes, as described above,
- an applicator for said composition;
- a means for heating the eyelashes to a temperature greater than or equal to 45°C.

The container can delimit one or more compartment(s). The container may be, for example, in the form of a tube.

Such an applicator may be secured to a cap mounted reversibly on said container between a closure position of said container and a makeup position.

In a variant, such an applicator can be irreversibly fitted to said container. As examples of applicators, mention may be made of those of felt type or brush type that may be constituted of synthetic fibres.

According to a particular embodiment, the applicator and the heating means may be integral with the packaging device comprising the cosmetic composition as described above, such as, for example, the heating mascaras as described in patents EP1466541B1, FR2865912B1, FR2869818B1, FR2946236B1, EP2445370B1, FR2947703B1, FR2996767B1 and FR3039379B1.

It is understood that, in the context of the present invention, the percentages by weight given for a compound or a family of compounds are always expressed by weight relative to the total weight of the composition.

Throughout the application, the term "contains one" or "comprises one" should be understood as meaning "containing at least one" or "comprising at least one", unless otherwise specified.

It is understood that the following examples are present by way of illustration and that they in no way limit the scope of the protection conferred by the present application.

Example 1 (invention): Eyelash curling product

The following composition was prepared.

Ingredients	Ex. 1
L-Cysteine (Ajinomoto)	10.0%
Sodium hydroxide pH = 9.5	3.4%
Hydroxyethylcellulose Cellosize HEC QP-4400H – (Amerchol/ Dow Chemical)	2%
2-Phenoxyethanol	0.5%
Caprylyl Glycol	0.3%
Water	qs 100

Preparation protocol

Example 1 was carried out using a Rayneri Turbotest VMI mixer equipped with a deflocculating spindle, under hot conditions of 70-75°C, and then cooled, at a rotation speed of 700-1500 rpm.

Comparative tests of eyelash curvature

Keratin fibres were curled according to three processes below:

Process according to the invention: reduction of the keratin fibres by application of Example 1 with air-convection heating at 60°C for 15 minutes in a rotating heat oven of the Firlabo BC120® incubator type, followed by rinsing and oxidation in the open air.

Process outside the invention: reduction of the keratin fibres by application of Example 1 at ambient temperature (25°C), followed by rinsing and air oxidation for 45 minutes at ambient temperature (25°C).

Process	Curling process of the invention	Curling process outside the invention without heating
Temperature at reduction step and exposure time	15 minutes at 60°C in the oven	15 minutes at ambient temperature (25°C)
Temperature at air oxidation step and exposure time	45 minutes at ambient temperature (25°C)	45 minutes at ambient temperature (25°C)

Method and results

The reducing composition of Example 1 was applied to keratin fibres (human hair) in a proportion of 380 mg of formula per 8 mg of keratin fibres.

The hair was then subjected to a mechanical stress via a ramp which has a radius of curvature of 5 mm and a tangent at the origin of 20°, for 15 min for the reduction and 45 min for the oxidation, at ambient temperature or with a heat stimulus for each step (BC120® from Firlabo).

The treated hair was then released from the mechanical stress and then cleansed according to the following protocol:
- cleansed with cotton wool soaked in La Roche Posay Respectissime® two-phase makeup remover;
- immersed in a bath of micellar solution for 2 minutes;
- makeup removed with cotton wool soaked in Garnier 's Solution Micellaire Tout-en-un® micellar water;
- dried with cotton wool at ambient temperature (25°C).

Quantifying the curvature of the fibre

The curvature is measured by measuring the maximum height of the fibre after treatment. A fibre of which the height is 0 cm corresponds to a fibre that has not been shaped, while a fibre of which the height is close to 1 cm corresponds to a fibre that has been completely shaped. The results obtained are summarized in the table below:

Curvature measurement	Variant 1 (invention)	Process without heating
Height (cm)	0.9	0.7
Standard deviation	0.1	0.06

The results showed significantly that the process for curling keratin fibres according to the invention with heating of said fibres leads to a better curvature than the process outside the invention without heating of the keratin fibres.

Claims (22)

1. Process for curling the eyelashes, comprising
   1) the application of a composition comprising, in particular in a physiologically acceptable medium:
   a) at least 40.0% by weight of water relative to the total weight of the composition; and
   b) cysteine and/or a salt thereof; said composition having a pH of greater than 8.5; and
   2) heating of the eyelashes to a temperature of greater than or equal to 45°C; the heating of the eyelashes being carried out during or after the application of said composition; said process not comprising a step of oxidation with an oxidizing agent other than air;
   the heating step being carried out during the step of reducing the keratin fibres with the composition, for a time ranging from 30 seconds to 45 minutes, and the heating being carried out at a temperature of from 45 to 65°C.
2. Process according to Claim 1, in which, in the composition, the cysteine is chosen from L-cysteine, D-cysteine or L,D-cysteine, and more particularly L-cysteine or a salt thereof.
3. Process according to Claim 1 or 2, in which, in the composition, the cysteine and/or one of the salts is present in a concentration of at least 0.5% by weight, more preferentially ranging from 1 to 20% by weight, more particularly from 8 to 15% by weight, relative to the total weight of the composition.
4. Process according to any one of the preceding claims, in which the pH of the composition ranges from 8.5 to 10.0.
5. Process according to any one of the preceding claims, in which the pH of the composition is obtained and/or adjusted by adding at least one alkaline agent and/or at least one acidifying agent and/or at least one buffering agent.
6. Process according to any one of the preceding claims, in which the composition additionally comprises sodium hydroxide.
7. Process according to any one of the preceding claims, in which the amount of water in the composition ranges from 50 to 92% by weight, and more preferentially from 60 to 90% by weight, relative to the total weight of the composition.
8. Process according to any one of the preceding claims, in which the composition additionally comprises at least one hydrophilic gelling agent, preferably chosen from non-ionic polysaccharides.
9. Process according to Claim 8, in which the hydrophilic gelling agent(s) is (are) present in a total content ranging from 0.1 to 10%, better still from 0.5 to 5% by weight, relative to the total weight of said composition.
10. Process according to any one of the preceding claims, in which the composition comprises at least one surfactant with an HLB of greater than
    or equal to 8.0, in particular chosen from anionic surfactants with an HLB of
    greater than or equal to 8.0, non-ionic surfactants with an HLB of greater than or equal
    to 8.0, and mixtures thereof.
11. Process according to Claim 10, in which, in the composition, the surfactant(s) with an HLB of greater than or equal to 8.0 is (are) present in a content ranging from 3.5 to 20.0% by weight, more preferentially from 4.0 to 20.0% by weight, better still from 4.5% to 15.0% by weight, and even better still from 5.0 to 15.0% by weight, relative to the total weight of the composition.
12. Process according to Claim 10 or 11, in which, in the composition, the anionic surfactant(s) with an HLB of greater than or equal to 8.0 is (are) chosen from alkyl sulfates, in particular ammonium lauryl sulfate.
13. Process according to Claim 10 or 11, in which, in the composition, the non-ionic surfactant(s) with an HLB of greater than or equal to 8.0 is (are) chosen from polyoxyalkylenated alcohols, in particular oleth-30.
14. Process according to any one of claims 10 to 13, in which the composition comprises at least one mixture of at least one anionic surfactant of the ammonium lauryl sulfate type and at least one non-ionic surfactant of the polyoxyalkylenated alcohol type, in particular a mixture of ammonium lauryl sulfate and oleth-30.
15. Process according to any one of the preceding claims, in which the composition comprises at least one fatty alcohol.
16. Process according to any one of the preceding claims, in which the composition is subjected to a conduction heating means before, during or after the application of the composition, in particular by means of a heating mascara or a heating eyelash curler.
17. Process according to any one of the preceding claims, in which the eyelashes are heated by air convection, in particular by means of a hair dryer, during or after the application of the composition.
18. Process according to any one of the preceding claims, in which the eyelashes are heated by infrared radiation during or after the application of the composition.
19. Process according to any one of the preceding claims, in which the application of the composition based on cysteine and/or a salt thereof is followed by a period in which said composition is left on the eyelashes thus treated, for a time ranging from 5 to 45 minutes.
20. Process according to Claim 19, in which, after the leave-on period, the eyelashes are cleansed and then dried, for example by means of dry cotton wool at ambient temperature (25°C).
21. Assembly or kit for treating the eyelashes, in particular assembly or kit for curling the eyelashes, comprising:
    i) a composition as defined according to any one of Claims 1 to 15, and
    ii) a means for heating the eyelashes to a temperature of greater than or equal to 45°C as defined according to any one of Claims 1 and 16 to 18.
22. Assembly or kit for curling the eyelashes, comprising:
    - a packaging device comprising the composition as defined in any one of Claims 1 to 15;
    - an applicator for said composition;
    - a means for heating the eyelashes to a temperature of greater than or equal to 45°C as defined in any one of Claims 1 and 16 to 18.