WO2020132861A1

WO2020132861A1 - Composition for cleansing keratin materials

Info

Publication number: WO2020132861A1
Application number: PCT/CN2018/123432
Authority: WO
Inventors: Liang Chen
Original assignee: L'oreal
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-07-02
Also published as: CN113395957A

Abstract

A composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprises, in an aqueous phase: a)at least one linear α-olefin sulfonate as anionic surfactant; and b)at least one organic acid as cosmetic active ingredient. A method for cleansing keratin materials, in particular the skin, comprises the application to the keratin materials, and rinsing off said composition after an optional period of time.

Description

COMPOSITION FOR CLEANSING KERATIN MATERIALS

FIELD OF THE INVENTION

The present invention relates to a cosmetic composition for keratin materials. The present invention also relates to a method for cleansing keratin materials using said composition.

BACKGROUD OF THE INVENTION

Cleansing the skin is very important for caring for the face. It must be as efficient as possible because greasy residues, such as excess sebum, the remnants of cosmetic products used daily, and make-up products, in particular waterproof products, accumulate in the skin folds, and can block the pores of the skin and result in the appearance of spots.

Several types of skin cleansing products, for example, rinsable cleansing anhydrous oils and gels, and foaming creams, lotions and gels, are known.

Rinsable anhydrous oils and gels have a cleansing action by virtue of oils present in these formulations. These oils make it possible to dissolve fatty residues and to disperse make-up pigments. These products are effective and well tolerated. However, they exhibit the disadvantages of being heavy, of not foaming and of not conferring a feeling of freshness on application, which is disadvantageous from a cosmetic viewpoint. Moreover, products of this type require dry hands when applying on the skin. The process is thus inconvenient.

On the other hand, foaming creams, lotions and gels have a cleansing action by virtue of the surfactants, which suspend the fatty residues on the face. They are effective and pleasant to use because they foam and because they are easy to remove. However the products of this type are not effective in terms of make-up removing, i.e., dissolving make-up pigments of make-up products.

Recently, cleansing products, in particular facial cleansing compositions, are expected to have not only good foaming ability, but also additional cosmetic effect, for example eliminating excess layers of dead skin cells from the skin surface (i.e. peeling) in order to provide a shiny skin with a youthful appearance.

Most of the foaming face cleansing products which are well-known in the prior art and are actually on the market are based on formulas that contain generally fatty acid salts (soaps) preferably with anionic surfactants of the sulphate type (ie alkylsulfates and alkylether sulfates) . However, the drawback to these formulas is that, in order to provide a high level of foaming performance, they need to use high quantities of surfactants (>20%) and consequently have a high pH (approximatively 9) . Those high quantities of soaps and sulphate surfactants may lead to skin irritation and discomfort on the skin after use (tight feeling, dry sensation) –especially with long term use.

It is known that some organic acid can be used to eliminating excess layers of dead skin cells from the skin surface. However, the addition of such organic acid will decrease the pH of the cleansing product and therefore adversely impact the foaming and rinsing ability.

Therefore, it is needed to formulate compositions for cleansing keratin materials with good cleansing properties and certain cosmetic effect brought by organic acid.

There is still a need for novel compositions with above described properties and good foaming property.

SUMMARY OF THE INVENTION

The inventors have found that such a need can be achieved by the present invention.

Thus, according to one aspect, the present invention relates to a composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprising, in an aqueous phase:

a) at least one linear α-olefin sulfonate as anionic surfactant; and

b) at least one organic acid as cosmetic active ingredient.

According to another aspect, the present invention provides a method for cleansing keratin materials, in particular the skin, comprising the application to the keratin materials, in particular the skin, of the composition according to the present invention, and rinsing off said composition after an optional period of time.

The composition according to the present invention is able to deliver a gentle massage and cleansing to the skin, without any harsh feeling.

The composition according to the present invention also delivers a good foaming and rinsing ability during application.

Furthermore, the composition according to the present invention also delivers certain cosmetic effect brought by organic acid, for example peeling effect/skin texture improvement.

It may be used as a daily facial cleanser. The composition of the present invention is a rinse off product. Thus, such a composition is applied on the skin (i.e. face and/or body) , and then rinsed with flush water.

Other subjects and characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the examples that follows.

DETAILED DESCRIPTION OF THE INVENTION

In that which follows and unless otherwise indicated, the limits of a range of values are included within this range, in particular in the expressions "of between" and "ranging from ... to ... " .

For the purposes of the present invention, the term “keratin material” is intended to cover human skin, mucous membranes such as the lips. Human skin, in particular facial skin, is most particularly considered according to the present invention.

Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more" .

Throughout the instant application, the term “comprising” is to be interpreted as encompassing all specifically mentioned features as well optional, additional, unspecified ones.

As used herein, the use of the term “comprising” also discloses the embodiment wherein no features other than the specifically mentioned features are present (i.e. “consisting of” ) .

According to one aspect, the present invention relates to a composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprising, in an aqueous phase:

a) at least one linear α-olefin sulfonate as anionic surfactant; and

b) at least one organic acid as cosmetic active ingredient.

Linear α-olefin sulfonates

The composition according to the present invention comprises at least one linear α-olefin sulfonate as anionic surfactant.

Said α-olefin sulfonates are known compounds and are described especially in Ullmann's Encyclopedia of Industrial Chemistry or in patent US 8211850. These compounds are generally obtained by sulfonation of long-chain α-olefins.

Preferably, the linear α-olefin sulfonate is selected from those of formula (I) :

R-CH ₂-CH=CH- (CH ₂) _n-SO ₃M (I)

in which:

- R is a saturated linear alkyl radical comprising from 4 to 30 carbon atoms, especially from 6 to 20 carbon atoms, or even from 8 to 18 carbon atoms and better still from 10 to 14 carbon atoms;

- n is an integer between 0 and 10, preferably between 1 and 4 and better still n=1;

- M is a cosmetically acceptable cation, chosen especially from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; preferably those derived from alkali metals; and especially Na ⁺or K ⁺.

Preferably, R represents a linear alkyl radical comprising from 8 to 14 carbon atoms, especially from 10 to 12 carbon atoms.

Preferably, M is derived from an alkali metal, especially Na ⁺or K ⁺.

Preferably, the linear alkene sulfonate according to the present invention has the structure of formula (II) :

in which:

- R is a saturated linear alkyl radical comprising from 4 to 20 carbon atoms, especially from 6 to 18 carbon atoms, or even from 8 to 14 carbon atoms and better still from 10 to 12 carbon atoms;

- M is a cosmetically acceptable cation, chosen especially from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; preferably those derived from alkali metals or alkali metals; and especially Na ⁺or K ⁺.

Preferably, the linear α-olefin sulfonates according to the invention are chosen from linear α-olefin sulfonates comprising 8 to 28 carbon atoms, especially from 10 to 24 carbon atoms, better still from 12 to 20 carbon atoms, in particular from 14 to 18 carbon atoms; in particular of alkali metals, especially of sodium, for example sodium C14-C16 olefin sulfonate.

Preferably, the linear α-olefin sulfonate is present in an amount ranging from 1 wt. %to 20 wt. %, preferably from 4 wt. %to 18 wt. %and more preferably from 5 wt. %to 15 wt. %, relative to the total weight of the composition.

Organic acid

The composition according to the present invention comprises at least one organic acid as cosmetic active ingredient.

Many organic acids can be used as cosmetic active ingredient to bring specific efficacy for example anti-Acne effect and/or peeling effect.

Peeling is well-known approach to improve the appearance and/or the texture of the skin and/or of the scalp, in particular improving the radiance and the homogeneity of the complexion and/or reducing the visible and/or tactile irregularities of the skin, and in particular for improving the surface appearance of the skin, for reducing actinic lentigo, acne marks and chickenpox marks, and also for preventing, reducing or combating the signs of skin aging, and in particular for smoothing out the irregularities of the skin's texture, such as wrinkles and fine lines.

Peeling has the effect of removing a superficial part of the skin (epidermis and possibly superficial layer of the dermis) .

Organic acid can be used as anti-acne and/or peeling agent is preferably selected from saturated and unsaturated monocarboxylic acids, saturated and unsaturated dicarboxylic acids, saturated and unsaturated tricarboxylic acids; α-hydroxy acids and β-hydroxy acids of monocarboxylic acids; α-hydroxy acids and β-hydroxy acids of dicarboxylic acids; α-hydroxy acids and β-hydroxy acids of tricarboxylic acids; keto acids, α-keto acids, β-keto acids of polycarboxylic acids, of polyhydroxymonocarboxylic acids, of polyhydroxydicarboxylic acids or of polyhydroxytricarboxylic acids; and (3-hydroxy-2-pentylcyclopentyl) acetic acid.

Preferred α-hydroxy acids that are exemplary include: glycolic acid, citric acid, lactic acid, tartaric acid, malic acid or mandelic acid.

Preferred β-hydroxy acids are selected from: salicyclic acid and derivatives thereof, in particular 5-n-octanoylsalicylic acid.

Those skilled in the art will be able to define the required amount of organic acid present in the composition according to the invention in order to obtain the desired effect on the skin.

Preferably, the organic acid is present in an amount ranging from 1 wt. %to 30 wt. %, preferably from 2 wt. %to 20 wt. %, more preferably from 3 wt. %to 15 wt. %, relative to the total weight of the composition.

More preferably, the α-hydroxy acid is present in an amount ranging from 1 wt. %to 10 wt. %, preferably from 1 wt. %to 6 wt. %, relative to the total weight of the composition.

More preferably, the β-hydroxy acid is present in an amount ranging from 0.1 wt. %to 2 wt. %, preferably from 0.2 wt. %to 1.0 wt. %, relative to the total weight of the composition.

Amphoteric surfactant (s)

According to a preferred embodiment, the composition of the present invention comprises at least one amphoteric surfactant (s) .

The inventors found that the composition according to the present invention due to coexistence of linear α-olefin sulfonate as anionic surfactant and amphoteric surfactant, the composition according to the present invention will have micellar texture and is stable over time.

“Stable over time” is understood to mean compositions of the present invention which, after storage at any temperature between 4℃ and 45℃ for 2 months, do not exhibit any macroscopic change in colour, smell or viscosity, any variation in pH or any variation in microscopic appearance.

The amphoteric surfactant (s) that may be used in the composition according to the present invention may be optionally quaternized secondary or tertiary aliphatic amine derivatives containing at least one anionic group, for instance a carboxylate, sulfonate, sulfate, phosphate or phosphonate group, and in which the aliphatic group or at least one of the aliphatic groups is a linear or branched chain comprising from 8 to 22 carbon atoms.

Among the (C ₈-C ₂₀) alkylbetaines, mentions may be made of behenylbetaine, cetyl betaine, cocoylbetaine, decylbetaine. From alkylbetaines, cocoylbetaine is preferred, for example the products sold by the company Rhodia under the tradename

BB/FLA.

Among the optionally quaternized secondary or tertiary aliphatic amine derivatives that may be used, mention may also be made of the products of respective structures (III) and (IV) below:

R _a-CON (Z) CH ₂- (CH ₂) _m-N ⁺ (R _b) (R _c) (CH ₂COO ^-) (III)

in which:

R _a represents a C ₁₀-C ₃₀ alkyl or alkenyl group derived from an acid R _a-COOH preferably present in hydrolysed coconut oil, a heptyl group, a nonyl group or an undecyl group,

R _b represents a β-hydroxyethyl group,

R _c represents a carboxymethyl group;

m is equal to 0, 1 or 2,

Z represents a hydrogen atom or a hydroxyethyl or carboxymethyl group;

R _a’-CON (Z) CH ₂- (CH ₂) _m’-N (B) (B') (IV)

in which:

B represents-CH ₂CH ₂OX', with X'representing-CH ₂-COOH, CH ₂-COOZ’, -CH ₂CH ₂-COOH, -CH ₂CH ₂-COOZ’, or a hydrogen atom,

B'represents- (CH ₂) _z-Y', with z=1 or 2, and Y'representing-COOH, -COOZ’, -CH ₂-CHOH-SO ₃H or -CH ₂-CHOH-SO ₃Z’,

m'is equal to 0, 1 or 2,

Z represents a hydrogen atom or a hydroxyethyl or carboxymethyl group,

Z’represents an ion resulting from an alkali or alkaline-earth metal, such as sodium, potassium or magnesium; an ammonium ion; or an ion resulting from an organic amine and in particular from an amino alcohol, such as monoethanolamine, diethanolamine and triethanolamine, monoisopropanolamine, diisopropanolamine or triisopropanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1, 3-propanediol and tris (hydroxymethyl) aminomethane,

R _a'represents a C ₁₀-C ₃₀ alkyl or alkenyl group of an acid R _a'COOH preferably present in hydrolysed linseed oil or coconut oil, an alkyl group, in particular a C ₁₇ alkyl group, and its iso form, or an unsaturated C ₁₇ group.

The compounds corresponding to formula (III) are preferred.

Use may also be made of the compounds of formula (V) :

R _a”-NH-CH (Y”) - (CH ₂) n-C (O) -NH- (CH ₂) n’-N (R _d) (R _e) (V)

in which:

- R _a″ represents a C ₁₀-C ₃₀ alkyl or alkenyl group of an acid R _a″ -C (O) OH preferably present in hydrolysed linseed oil or coconut oil;

- Y'’represents the group–C (O) OH, -C (O) OZ”, -CH ₂-CH (OH) -SO ₃H or the group-CH ₂-CH (OH) -SO ₃-Z”, with Z”representing a cationic counterion resulting from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion resulting from an organic amine;

- R _d and R _e represent, independently of each other, a C ₁-C ₄ alkyl or hydroxyalkyl radical; and

- n and n'denote, independently of each other, an integer ranging from 1 to 3.

Mention may be made in particular of betaine-based amphoteric surfactant, for example, (C ₈-C ₂₀) alkylbetaines, sulfobetaines, (C ₈-C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) betaines and (C ₈–C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) sulfobetaines.

Preferably, the amphoteric surfactants are chosen from (C ₈-C ₂₀) alkylbetaines, (C ₈-C ₂₀) alkylamido (C ₂-C ₈) alkylbetaines, and mixtures thereof.

More preferably, the amphoteric surfactant is chosen from cocamidopropyl betaine, cocoylbetaine, and mixture thereof.

Advantageously, the amphoteric surfactant is present in the composition in an amount ranging from 0.5 wt. %to 20 wt. %, preferably from 1 wt. %to 15 wt. %, more preferably 2 wt. %to 10 wt. %relative to the total weight of the composition.

Thickening agent

Optionally, the composition according to the present invention comprises at least one thickening agent.

The thickening agent can be any hydrophilic thickening agent useful for thickening the aqueous phase of cosmetic composition in the art.

In an embodiment, the composition according to the present invention is AMPS polymer, for example ammonium polyacryloyldimethyl taurate.

The skilled in the art can adjust the amount of the thickening agent as desired. For example, the thickening is present in the composition in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 1 wt. %to 5 wt. %, relative to the total weight of the composition.

pH adjusting agent

The composition of the present invention has a pH of 3.5-5.0, preferably 3.8.

In order to adjust the pH of the composition according to the present invention, pH adjusting agent can be added.

As example of pH adjusting agent, mention can be made to citric acid and sodium hydroxide.

The skilled in the art can adjust the amount of the pH adjusting agent as desired.

Aqueous phase

The composition of the present invention comprises at least one aqueous phase.

According to a preferred embodiment, the composition of the present invention is an aqueous solution.

The aqueous phase of the composition according to the present invention comprises water and optionally one or more water-miscible or at least partially water-miscible compounds, for instance C ₂ to C ₈ lower polyols or monoalcohols, such as ethanol and isopropanol.

The term “polyol” should be understood as meaning any organic molecule comprising at least two free hydroxyl groups. Examples of polyols that may be mentioned include glycols, for instance butylene glycol, propylene glycol, and isoprene glycol, caprylyl glycol, glycerol (i.e. glycerin) and polyethylene glycols.

The aqueous phase may also comprise any common water-soluble or water-dispersible additive as mentioned below.

The aqueous phase may represent from 30 wt. %to 98 wt. %, preferably from 30 wt. %to 95 wt. %, better still from 50 wt. %to 90 wt. %and even better still from 60 wt. %to 90 wt. %, relative to the total weight of the composition.

Additional ingredient (s)

Optionally, a composition according to the present invention may further comprise one or more additional ingredients.

A person skilled in the art can adjust the type and amount of additional ingredients present in the compositions according to the present invention by means of routine operations, so that the desired cosmetic properties and foaming properties for these compositions are not adverserly affected by the additional ingredients.

According to a preferred embodiment, the present invention relates to a composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprising, in an aqueous phase, relative to the total weight of the composition:

a) from 5 wt. %to 15 wt. %of at least one linear α-olefin sulfonate of formula (II) :

in which:

- M is a cosmetically acceptable cation chosen from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; and especially Na ⁺or K ⁺;

b) from 3 wt. %to 15 wt. %at least one organic acid selected from glycolic acid, citric acid, lactic acid, tartaric acid, malic acid, mandelic acid, salicyclic acid and 5-n-octanoylsalicylic acid; and

c) from 2 wt. %to 10 wt. %at least one amphoteric surfactant selected from (C ₈-C ₂₀) alkylbetaines, sulfobetaines, (C ₈-C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) betaines and (C ₈–C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) sulfobetaines.

Method and use

The composition according to the present invention can be used for a process for cleansing keratin materials, such as the skin, in particular the face, by being applied to the keratin materials.

The composition according to the invention may be applied by any means enabling a uniform distribution, in particular using a finger, or a cotton ball, a rod, a brush, gauze, or a spatula, and can be removed by rinsing with water.

The composition of the invention may be implemented so as to improve the general state of the epidermis, in particular the skin.

Thus, according to another aspect, the present invention relates to a method for cleansing keratin materials, in particular the skin, comprising the application to the keratin materials, in particular the skin, of the composition according to the present invention, and rinsing off said composition after an optional period of time.

The present invention is illustrated in greater detail by the examples described below, which are given as non-limiting illustrations.

The percentages are weight percentages by active ingredient, or active matters.

In the examples that follow, the weight percentages are indicated relative to the total weight of the composition.

EXAMPLES

Example 1: Preparation examples

The compositions according to invention formulas (inv. ) and comparative formula (comp. ) comprising the ingredients shown in table 1 were prepared, with all amounts expressed by percentages by weight of active matter with regard to the total weight of each composition.

The compositions according to formulas listed above were prepared according to known preparation methods in cosmetic field.

Example 2: Evaluation of the properties of the composition according to formulas listed above

The stability was measured after storage during one month at 4℃, 25℃ (room temperature or RT) , 40℃ or 45℃.

Stability tests are also performed under sun test and during several cycles.

Stability under sun test was performed by leaving the cosmetic composition of the invention in a Suntest CPS+ produced by Atlas for 24 hours.

Cycle stability test was performed at a cycle of-20℃ to 20℃ every 24 hours, for 10 days.

The foaming and rinsing ability of the compositions according to invention and comparative formulas listed above were evaluated.

The protocol was as follow:

a. cleansing the palms with cleansing cream;

Wetting palm, placing 1.0 g of the above mentioned compositions on one palm;

b. Add 1g water and then rubbing between palms for 20 cycles;

Adding another 1 g of water; and

c. Rubbing between palms for another 20 circles;

d. Evaluating volume and density of the foam by simply observing and pressing the foam between palms;

Removing the foam to the back of one hand, rinsing off the foam with water taken by the other hand;

e. Evaluating rinsing ability by times of rinsing required to have instant squeaky feeling.

The foaming (including volume and dense) and rinsing were scored by the 20 consumers based on the following standards.

The effects on anti-acne, oil-control as well as skin texture improvement of the compositions according to invention and comparative formulas listed above were evaluated by application of the above formulas for 7 days period by 20 consumers (10 males and 10 females) aged from 18-35 with oily or combination to oily skin, all the consumers have acne, roughness, dullness skin or pore concern which want to be address immediately.

The results of the evaluations are as follows:

N/A: not evaluated.

It can be seen that all of the compositions according to invention formula 1-3 possess good foaming ability and rinsing ability. In addition, the compositions according to invention formulas 2-3 are stable over time for at least 2 months.

On the other hand, the composition according to comparative formula does not have good foaming ability.

Claims

A composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprising, in an aqueous phase:

a) at least one linear α-olefin sulfonate as anionic surfactant; and

b) at least one organic acid as cosmetic active ingredient.
The composition according to claim 1, wherein the linear α-olefin sulfonate is selected from those of formula (I) :

R-CH ₂-CH=CH- (CH ₂) _n-SO ₃M (I)

in which:

- R is a saturated linear alkyl radical comprising from 4 to 30 carbon atoms, especially from 6 to 20 carbon atoms, or even from 8 to 18 carbon atoms and better still from 10 to 14 carbon atoms;

- n is an integer between 0 and 10, preferably between 1 and 4 and better still n=1;

- M is a cosmetically acceptable cation, chosen especially from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; preferably those derived from alkali metals; and especially Na ⁺ or K ⁺.
The composition according to claim 1 or 2, wherein the linear α-olefin sulfonate has the structure of formula (II) :

in which:

- R is a saturated linear alkyl radical comprising from 4 to 20 carbon atoms, especially from 6 to 18 carbon atoms, or even from 8 to 14 carbon atoms and better still from 10 to 12 carbon atoms;

- M is a cosmetically acceptable cation, chosen especially from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; preferably those derived from alkali metals or alkali metals; and especially Na ⁺ or K ⁺.
The composition according to any of claims 1 to 3, wherein the linear α-olefin sulfonate is present in an amount ranging from 1 wt. %to 20 wt. %, preferably from 4 wt. %to 18wt. %and more preferably from 5 wt. %to 15 wt. %, relative to the total weight of the composition.
The composition according to any one of claims 1 to 4, wherein the organic acid glycinate surfactant is from saturated and unsaturated monocarboxylic acids, saturated and unsaturated dicarboxylic acids, saturated and unsaturated tricarboxylic acids; α-hydroxy acids and β-hydroxy acids of monocarboxylic acids; α-hydroxy acids and β-hydroxy acids of dicarboxylic acids; α-hydroxy acids and β-hydroxy acids of tricarboxylic acids; keto acids, α-keto acids, β-keto acids of polycarboxylic acids, of polyhydroxymonocarboxylic acids, of polyhydroxydicarboxylic acids or of polyhydroxytricarboxylic acids; and (3-hydroxy-2-pentylcyclopentyl) acetic acid.
The composition according to any one of claims 1 to 5, wherein the organic acid is present in an amount ranging from ranging from 1 wt. %to 30 wt. %, preferably from 2 wt. %to 20 wt.%, more preferably from 3 wt. %to 15 wt. %, relative to the total weight of the composition.
The composition according to any one of claims 1 to 6, further comprising at least one amphoteric surfactant.
The composition according to claim 7, wherein the amphoteric surfactant is selected from (C ₈-C ₂₀) alkylbetaines, sulfobetaines, (C ₈-C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) betaines and (C ₈–C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) sulfobetaines.
The composition according to claim 7, wherein the amphoteric surfactant is selected from cocamidopropyl betaine, cocoylbetaine, and mixture thereof.
The composition according to claim 7, wherein the amphoteric surfactant is present in an amount ranging from ranging from 0.5 wt. %to 20 wt. %, preferably from 1 wt. %to 15 wt. %, relative to the total weight of the composition.
The composition of any one of claims 1 to 10, further comprising at least one thickener.
A composition for cleansing keratin materials with a pH from 3.5 to 5.0, comprising, in an aqueous phase, relative to the total weight of the composition:

a) from 5 wt. %to 15 wt. %of at least one linear α-olefin sulfonate of formula (II) :

in which:

- R is a saturated linear alkyl radical comprising from 4 to 20 carbon atoms, especially from 6 to 18 carbon atoms, or even from 8 to 14 carbon atoms and better still from 10 to 12 carbon atoms;

- M is a cosmetically acceptable cation chosen from the ammonium cation, cations derived from alkali metals or alkaline-earth metals, cations derived from organic amines such as alkanolamines; and especially Na ⁺ or K ⁺;

b) from 3 wt. %to 15 wt. %at least one organic acid selected from glycolic acid, citric acid, lactic acid, tartaric acid, malic acid, mandelic acid, salicyclic acid and 5-n-octanoylsalicylic acid; and

c) from 2 wt. %to 10 wt. %at least one amphoteric surfactant selected from (C ₈-C ₂₀) alkylbetaines, sulfobetaines, (C ₈-C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) betaines and (C ₈–C ₂₀ alkyl) amido (C ₂-C ₈ alkyl) sulfobetaines.
A method for cleansing keratin materials, in particular the skin, comprising the application to the keratin materials, in particular the skin, of the composition according to any one of claims 1 to 12, and rinsing off said composition after an optional period of time.