WO2018076355A1

WO2018076355A1 - Cosmetic composition with wax microbeads

Info

Publication number: WO2018076355A1
Application number: PCT/CN2016/104088
Authority: WO
Inventors: Jiejin LIU; Hui Liu
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2016-10-31
Filing date: 2016-10-31
Publication date: 2018-05-03
Anticipated expiration: 2019-04-30

Abstract

A composition comprises, in an aqueous phase: a) a copolymer of a C ₁₀-C ₃₀ alkyl acrylate and of acrylic or methacrylic acid, crosslinked with an allyl ether of sucrose or an allyl ether of pentaerythritol; and b) wax beads having a median particle size by volume Dv50 ranging from 50 micrometers to 300 micrometers, and wherein the wax has a melting point greater than or equal to 60℃. The composition may be incorporated into a cleansing and/or exfoliating cosmetic composition.

Description

COSMETIC COMPOSITION WITH WAX MICROBEADS

The present invention relates to cleansing and/or exfoliating compositions that are useful for personal skin care.

The skin is the protective barrier for the human body. It protects the interior of the body from physical injury (such as trauma) and biological injury (such as bacteria, viruses or fungi) . The skin of the human body comprises the dermis and the epidermis. The epidermis is the top most layer of the skin, and its superficial layer is called the stratum corneum.

The stratum corneum, or horny layer, is normally made up of 10 to 30 layers of dead cells. These cells are constantly being replaced by new cells from below. It is estimated that in adult skin it takes about a month for the stratum corneum to be completely replaced by new cells. The replacement time increases with aging, until around 120-150 days. The longer it takes to replace the dead cells, the more layers of dead cells accumulate.

It is therefore desirable to eliminate excess layers of dead skin cells from the skin surface in order to provide a shiny skin with a youthful appearance. The process of removing dead skin cells from the skin surface is called exfoliation.

Currently, human skin is cleaned and/or exfoliated using a number of different ways, such as cleansing products with or without mechanical scrubbing using hard particles of any kind. These particles are also called scrub beads. Classical cleansing or exfoliating compositions currently on the market can be categorized into cleansing compositions with or without scrub beads. It is known that the addition of scrub beads provides a stronger and better cleansing ability to the skin, in particular pore cleansing. These beads may be hydrocarbon wax beads, particles such as silica, and polyethylene (PE) beads.

However there are several problems associated with each of these beads. Indeed:

- hydrocarbon wax beads are relatively large in size, notably 300 to 2000 μm, and tend to be soft in cleansing or exfoliating formula, which is not desired；

- particles such as silica tend to result in a too small size (i.e. nanoparticles) during production, which causes dust issue； and

- PE beads break during application, which is not applicable to cleansing purposes.

Besides, scrub beads that are known tend to be harsh after applying on the skin. This is even worse to consumers of sensitive skin type.

There is thus a need for stable cleansing and/or exfoliating compositions presenting scrub beads which have an adequate size and which do not soften over time and/or temperature change.

There is also a need for delivering stable cleansing and/or exfoliating compositions comprising scrub beads which provide a good removability of the dust, in particular for pore cleansing.

Moreover, there is a need for exfoliating compositions with the properties mentioned above, and meanwhile which are gentle to the skin, i.e., do not cause redness, irritation, or inflammation on skin.

The Applicant has now discovered that it is possible to formulate compositions having the desired properties as described above, by combining a specific polymer with wax beads having a specific defined size.

Accordingly, the present invention relates to a composition (also called “the composition of the invention” ) comprising, in an aqueous phase:

a) a copolymer of a C₁₀-C₃₀ alkyl acrylate and of acrylic or methacrylic acid, crosslinked with an allyl ether of sucrose or an allyl ether of pentaerythritol； and

b) wax beads having a median particle size by volume Dv50 ranging from 50 micrometers to 300 micrometers, and wherein said wax has a melting point greater than or equal to 60℃.

The composition of the invention is able to deliver a gentle massage to skin, without any harsh feeling. It may be daily used as a facial or body cleanser and/or exfoliating composition. Moreover, the composition of the invention is stable without softening over time and/or temperature change. By stable, it is meant that the composition does not undergo any significant change in its structure or properties for at least one month after its manufacture and especially for at least two months after its manufacture.

The wax beads of the invention are useful for cleansing the skin, and present a desired size and shape, which is favored by the consumers.

The present invention also relates to a cosmetic composition for cleansing and/or exfoliating the skin (also called “the cosmetic composition of the invention” ) comprising the composition as defined above, and at least one surfactant chosen from anionic surfactants, nonionic surfactants, amphoteric surfactants, zwitterionic surfactants and their mixtures.

Such a cosmetic composition is a rinse off product. Thus, such a cosmetic composition is applied on skin (i.e. face and/or body) , and then rinsed.

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

The median particle size by volume Dv50 as disclosed in the present invention is a parameter for particle size distribution, referring to the maximum particle diameter below which 50％of the sample volume exists (see in A Basic Guide To Particle Characterization, page 10, published by Malvern Instruments Limited in 2012) .

The particle size by volume Dv50 of the wax beads may be measured by static light scattering using a commercial granulometer such as the MasterSizer 3000 machine from Malvern. The data are processed on the basis of the Mie scattering theory. This theory, which is exact for isotropic particles, makes it possible to determine, in the case of non-spherical particles, an "effective" particle diameter. This theory is especially described in the publication by Van de Hulst, H.C., "Light Scattering by Small Particles, " Chapters 9 and 10, Wiley, New York, 1957.

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 ... " .

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” ) .

The composition of the invention comprises, in an aqueous phase:

The copolymer a) is made of a C₁₀-C₃₀ alkyl acrylate and of acrylic or methacrylic acid, crosslinked with an allyl ether of sucrose or an allyl ether of pentaerythritol. The proportion of acrylic or methacrylic acid present in the copolymer may range from 50 to 99％by weight, preferably from 90 to 98％by weight, and the proportion of C₁₀-C₃₀ alkyl acrylate may range from 50 to 1％by weight, preferably from 10 to 2％by weight.

The copolymer used in the present invention is preferably chosen from those marketed under the names Pemulen^TM TR1, Pemulen^TM TR2 and

Ultrez 21 Polymer by Lubrizol.

The copolymer used in the present invention is preferably present in an amount ranging from 0.1％to 1％by weight, more preferably from 0.2％to 0.8％by weight of the total weight of the composition.

The composition of the invention further comprises wax beads b) .

Preferably, they are present in an amount ranging from 1％to 30％by weight, preferably from 2％to 10％by weight of the total weight of the composition.

The wax beads b) present a median particle size by volume Dv50 ranging from 50 micrometers to 300 micrometers.

The median particle size by volume Dv50 of the wax beads of the invention range from 50 micrometers to 300 micrometers, preferably from 100 micrometers to 200 micrometers.

Furthermore, the wax used for the beads b) has a melting point greater than or equal to 60℃. The waxes under consideration in the context of the present invention are generally deformable or nondeformable solid lipophilic compounds at ambient temperature (25℃) which exhibit a reversible solid/liquid change in state and which have a melting point of greater than or equal to 60℃, which can range up to 200℃ and in particular up to 120℃.

Within the meaning of the invention, the melting point corresponds to the temperature of the most endothermic peak observed in thermal analysis (DSC) as described in the standard ISO 1 1357-3； 1999. The melting point of the wax can be measured using a differential scanning calorimeter (DSC) , for example the calorimeter sold under the name MDSC 2920 by TA Instruments.

The measurement protocol is as follows:

A sample of 5 mg of wax placed in a crucible is subjected to a first temperature rise ranging from -20℃ to 100℃, at a heating rate of 10℃/minute, it is then cooled from 100℃ to -20℃ at a cooling rate of 10℃/minute and finally it is subjected to a second temperature rise ranging from -20℃ to 100℃, at a heating rate of 5℃/minute. During the second temperature rise, the variation in the difference in power absorbed by the empty crucible and by the crucible containing the sample of wax is measured as a function of the temperature. The melting point of the wax is the value of the temperature corresponding to the tip of the peak of the curve representing the variation in the difference in power absorbed as a function of the temperature.

The waxes capable of being used in a composition according to the invention are chosen from waxes of animal, vegetable, mineral or synthetic origin and their mixtures which are solid at ambient temperature and which have a melting point greater than or equal to 60℃. They can be hydrocarbon, fluorinated and/or silicone waxes.

Mention may in particular be made, by way of examples, of hydrocarbon waxes, such as natural beeswax (or bleached beeswax) such as that sold under the reference SP 453 P by Strahl &Pitsch, synthetic beeswax, carnauba wax such as that sold under the reference SP 63 (#1 Flakes NF) by Strahl &Pitsch, rice bran wax such as that sold under the reference NC 1720 by Cera Rica Noda, candelilla wax such as that sold under the reference SP 75 G by Strahl &Pitsch, microcrystalline waxes such as, for example, the microcrystalline waxes having a melting point of greater than 85℃, such as the products

1070, 1080, 1090 and 3080 sold by Nippon Seiro, or fluorinated waxes. Among the silicone waxes, one can quote alkyl or alkoxy dimethicones having from 16 to 45 carbon atoms, and preferably C_30-45 alkyl dimethicone such as that sold under the reference SF1642 by Momentive Performance Materials, or the silicone compound of the following formula:

[CH₃CH₂CH₂SiO_3/2] _x [R (CH₃) ₂SiO_1/2] _y

wherein R is – (CH₂) _nCH₃, and n is an integer from 30 to 45, such as that sold under the reference SW-8005 C30 resin wax by Dow Corning (INCI name: C_30-45 alkyldimethylsilyl polypropylsilsesquioxane) .

Preferably, the wax having a melting point greater than or equal to 60℃ is chosen from beeswax, candelilla wax, carnauba wax, C_30-45 alkyl dimethicone and the silicone compound of the following formula:

[CH₃CH₂CH₂SiO_3/2] _x [R (CH₃) ₂SiO_1/2] _y

wherein R is – (CH₂) _nCH₃, and n is an integer from 30 to 45.

The copolymer a) and the wax beads b) are comprised in an aqueous phase. Said aqueous phase is preferably present in an amount ranging from 70％to 99％by weight, more preferably from 80％to 97％by weight of the total weight of the composition. Preferably, the aqueous phase is a continuous aqueous phase.

According to an embodiment, the aqueous phase includes water.

The aqueous phase may also comprise at least one organic solvent miscible with water (at room temperature -25℃) such as for example monoalcohols having from 2 to 6 carbon atoms such as ethanol, isopropanol； polyols notably having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, and preferentially having from 2 to 6 carbon atoms, such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylylglycol, dipropylene glycol, diethylene glycol； glycol ethers (notably having from 3 to 16 carbon atoms) such as mono-, di-or tri-propylene glycol (C₁-C₄) alkyl ethers, mono-, di-or tri-ethylene glycol (C₁-C₄) alkyl ethers and mixtures thereof.

Preferably, the aqueous phase of the composition of the invention comprises water and a polyol, preferably glycerol or propylene glycol, or a monoalcohol, preferably ethanol.

According to an embodiment, the amount of water in the compositions according to the invention ranges from 70％to 99％by weight, preferably from 85％to 95％by weight relative to the total weight of the composition.

According to a preferred embodiment, the present invention relates to a composition for cleansing keratin materials, in particular the skin, comprising, in an aqueous phase:

a) from 0.1％to 1％by weight of a copolymer of a C₁₀-C₃₀ alkyl acrylate and of acrylic or methacrylic acid, crosslinked with an allyl ether of sucrose or an allyl ether of pentaerythritol； and

b) from 1％to 30％by weight of wax beads having a median particle size by volume Dv50 ranging from 50 micrometers to 300 micrometers, and wherein said wax has a melting point greater than or equal to 60℃, wherein the wax is selected from the group consisting of beeswax, candelilla wax, carnauba wax, C_30-45 alkyl dimethicone and the silicone compound of the following formula:

[CH₃CH₂CH₂SiO_3/2] _x [R (CH₃) 2SiO_1/2] _y

wherein R is – (CH₂) _nCH₃, and n is an integer from 30 to 45.

The present invention also relates to a process for preparing the composition as described above, comprising the following steps:

i) dispersing the copolymer a) in the aqueous phase, and heating the dispersion to a temperature greater than 60℃；

ii) melting the wax having a melting point greater than or equal to 60℃, and adding it to the heated dispersion obtained in i) , so as to obtain a mixture；

iii) homogenizing the mixture obtained in ii) so as to obtain the targeted bead size； and

iv) cooling while stirring the mixture obtained in iii) so as to achieve wax beads.

Such a process of the invention is easy to perform, and without issues such as dust generated during production.

The present invention also relates to a composition for cleansing and/or exfoliating keratin materials, in particular the skin ( “cosmetic composition” ) , comprising the composition of the invention as described above, and at least one surfactant chosen from anionic surfactants, nonionic surfactants, amphoteric surfactants, zwitterionic surfactants and their mixtures.

Advantageously, the anionic surfactant means a surfactant comprising, as ionic or ionizable groups, only anionic groups. These anionic groups are preferably chosen from -CO₂H, -CO₂ ^-, -SO₃H, -SO₃ ^-, -OSO₃H, -OSO₃ ^-, -H₂PO₃, -HPO₃ ^-, -PO₃ ^2-, -H₂PO₂, ＝HPO₂, -HPO₂ ^-, ＝PO₂ ^-, ＝POH, and ＝PO^-groups. Mention may be made of alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkylsulfonates, alkylamidesulfonates, alkylarylsulfonates, α-olefin sulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfoacetates, acylsarcosinates, acylglutamates, alkyl sulfosuccinamates, acylisethionates and N-acyltaurates, polyglycoside polycarboxylic acid and alkyl monoester salts, acyl lactylates, salts of D-galactoside uronic acids, salts of alkyl ether carboxylic acids, salts of alkylaryl ether carboxylic acids, salts of alkylamido ether carboxylic acids； and the corresponding non-salified forms of all these compounds； the alkyl and acyl groups of all these compounds comprising from 6 to 24 carbon atoms and the aryl group denoting a phenyl group. Another group of anionic surfactants that may be used in the composition of the present invention is that of acyl lactylates, the acyl group of which comprises from 8 to 20 carbon atoms.

In addition mention may also be made of alkyl-D-galactoside-uronic acids and their salts, and also of polyoxyalkylenated (C_6-24) alkyl ether carboxylic acids, polyoxyalkylenated (C_6-24) alkyl (C_6-24) aryl ether carboxylic acids, polyoxyalkylenated (C_6- ₂₄)alkylamido ether carboxylic acids and salts thereof, especially those containing from 2 to 50 ethylene oxide units, and mixtures thereof.

When the anionic surfactant (s) are in salt form, they may be chosen from alkali metal salts such as the sodium or potassium salt and preferably the sodium salt, ammonium salts, amine salts and in particular amino alcohol salts or alkaline-earth metal salts such as the magnesium salts. Examples of amino alcohol salts that may especially be mentioned include monoethanolamine, diethanolamine and triethanolamine salts, monoisopropanolamine, diisopropanolamine or triisopropanolamine salts, 2-amino-2-methyl-1-propanol salts, 2-amino-2-methyl-1, 3-propanediol salts and tris (hydroxymethyl) aminomethane salts. Alkali metal or alkaline-earth metal salts, and in particular sodium or magnesium salts, are preferably used.

Nonionic surfactants which may be mentioned include oxyalkylenated (more particularly polyoxyethylenated) esters of fatty acids and of glycerol； oxyalkylenated esters of fatty acids and of sorbitan； oxyalkylenated (oxyethylenated and/or oxypropylenated) esters of fatty acids, such as the PEG-100 stearate/glyceryl stearate mixture sold, for example, by ICI under the name Arlacel 165； oxyalkylenated (oxyethylenated and/or oxypropylenated) ethers of fatty alcohols； esters of sugars, such as sucrose stearate； ethanolamine and its derivatives, such as cocamide MEA； or ethers of fatty alcohol and of sugar, in particular alkyl polyglucosides (APGs) , such as decyl glucoside and lauryl glucoside, sold, for example, by the company Henkel under the respective names Plantaren 2000 and Plantaren 1200, cetostearyl glucoside, optionally as a mixture with cetostearyl alcohol, sold, for example, under the name Montanov 68 by the company SEPPIC, under the name Tegocare CG90 by the company Goldschmidt and under the name Emulgade KE3302 by the company Henkel, and also arachidyl glucoside, for example in the form of the mixture of arachidyl alcohol, behenyl alcohol and arachidyl glucoside, sold under the name Montanov 202 by the company SEPPIC.

The amphoteric or zwitterionic surfactants that may be used in the present invention may especially be derivatives of optionally quaternized aliphatic secondary or tertiary amines, in which derivatives the aliphatic group is a linear or branched chain comprising from 8 to 22 carbon atoms, the said amine derivatives containing at least one anionic group, for instance a carboxylate, sulfonate, sulfate, phosphate or phosphonate group. Mention may be made in particular of (C₈-C₂₀) alkylbetaines, sulfobetaines, (C₈-C₂₀) alkylamido (C₃-C₈) alkylbetaines and (C₈-C₂₀) alkylamido (C₆-C₈) alkylsulfobetaines.

Among the optionally quaternized secondary or tertiary aliphatic amine derivatives that can be used, as defined above, mention may also be made of the compounds of respective structures (A1) and (A2) below:

R_aCONHCH₂CH₂N⁺ (R_b) (R_c) (CH₂COO^-) (A1)

in which:

· R_a represents a C₁₀-C₃₀ alkyl or alkenyl group derived from an acid R_aCOOH preferably present in hydrolysed coconut oil, or a heptyl, nonyl or undecyl group；

· R_b represents a β-hydroxyethyl group, and

· R_c represents a carboxymethyl group；

and

R_a'CONHCH₂CH₂N (B) (B') (A2)

in which:

· B represents the group -CH₂CH₂OX',

· B'represents the group - (CH₂) _zY', with z ＝ 1 or 2,

· X'represents the group -CH₂COOH, CH₂COOZ', -CH₂CH₂COOH, -CH₂CH₂COOZ', or a hydrogen atom,

· Y'represents the group -COOH, -COOZ', the group -CH₂CHOHSO₃H or the group -CH₂CHOHSO₃Z',

· Z'represents an ion resulting from an alkali metal or alkaline earth metal, such as sodium, an ammonium ion or an ion resulting from an organic amine,

· R_a'represents a C₁₀-C₃₀ alkyl or alkenyl group of an acid R_a'COON preferably present in coconut oil or in hydrolysed linseed oil, an alkyl group, especially of C₁₇ and its iso form, or an unsaturated C₁₇ group.

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names disodium cocoamphodiacetate, disodium lauroamphodiacetate, disodium caprylamphodiacetate, disodium capryloamphodiacetate, disodium cocoamphodipropionate, disodium lauroamphodipropionate, disodium caprylamphodipropionate, disodium capryloamphodipropionate, lauroamphodipropionic acid and cocoamphodipropionic acid. By way of example, mention may be made of the cocoamphodiacetate sold by the company Rhodia under the trade name

C2M Concentrate.

Among the amphoteric or zwitterionic surfactants mentioned above, use is preferably made of (C₈-C₂₀) alkylbetaines such as cocoylbetaine (or cocobetaine) , and (C₈-C₂₀) alkylamido (C₃-C₈) alkylbetaines such as cocamidopropylbetaine, and mixtures thereof. More preferentially, the amphoteric or zwitterionic surfactant (s) are chosen from cocamidopropylbetaine and cocobetaine.

According to an embodiment, the amount of surfactant (s) in the cosmetic composition according to the invention ranges from 0.1％to 30％by weight, preferably from 5％to 25％by weight, relative to the total weight of the composition.

The cosmetic composition of the present invention may further comprise at least one additive. A person skilled in the art can adjust the type and amount of additives present in the compositions according to the invention by means of routine operations, so that the desired cosmetic properties and stability properties for these compositions are not affected by the additives. Said additive may be chosen from thickeners, colorants and preservatives.

The thickeners may advantageously be chosen from xanthan, guar, hydroxypropyl guar, scleroglucan, methyl cellulose, ethyl cellulose (available as

) , hydroxyethyl cellulose

carboxymethyl cellulose, hydroxypropylmethyl cellulose, microcrystalline cellulose, hydroxybutylmethyl cellulose, hydroxypropyl cellulose (available as

) , hydroxyethyl ethyl cellulose, cetyl hydroxyethyl cellulose (available as

Plus 330) , N-vinylpyrolidone (available as

) , Acrylates/Ceteth-20 Itaconate Copolymer (available as

3001) , hydroxypropyl starch phosphate (available as

ZEA) , polyethoxylated urethanes or polycarbamyl polyglycol ester (e.g. PEG-150/Decyl/SMDI copolymer (e.g.

44) , PEG-150/Stearyl/SMDI copolymer (available as

46) , trihydroxystearin (available as

) , acrylates copolymer (e.g. available as

33) or hydrophobically modified acrylate copolymers (e.g. acrylates/steareth-20 methacrylate copolymer (available as

22) , acrylates/steareth-20 methacrylate crosspolymer (available as

88) , acrylates/vinyl neodecanoate crosspolymer (available as

38) , acrylates/beheneth-25 methacrylate copolymer (available as

28) and acrylates/C^10-30 alkyl acrylate crosspolymer (available as

ETD 2020) .

The colorants may be chosen from pigments, dyes and nacres. Pigments include white or colored particles, mineral or organic, intended for coloring and/or opacifying the resultant product. Preferably, pigments or nacres, if present, are present in an amount ranging from 0.01 to 30％by weight, more preferably from 0.01 to 20％by weight relative to the total weight of the composition.

The preservatives may be chosen from propyl p-hydroxybenzoate (propyl paraben) , methyl p-hydroxybenzoate (methyl paraben) , butyl p-hydroxybenzoate (butyl paraben) and phenoxyethanol.

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.

The present invention also relates to a method for cleansing and/or exfoliating keratin materials, in particular the skin, comprising the application to the keratin materials, in particular the skin, of the cosmetic composition according to the invention.

The invention also relates to the use of the cosmetic composition according to the invention for cleansing and/or exfoliating keratin materials, in particular the skin.

The following examples serve to illustrate the invention without, however, being limiting in nature.

EXAMPLES

Example 1: Preparation of a composition according to the present invention

A composition 1 according to the invention was prepared according to the amounts given in table 1 hereafter.

The invention formula was prepared following the steps of:

mix the aqueous phase A2, then disperse phase A1 into phase A2, and heat to a temperature greater than 60℃；

melt phase B by heating to 80℃, until totally melting；

add phase B into the mixture of phases A1 and A2, homogenize for 10～15 min, then cool down to 35℃.

Example 2: Preparation of a cosmetic composition according to the present invention and a comparative cosmetic composition

A cosmetic composition 2 according to the invention and a comparative cosmetic composition 2’were prepared according to the amounts given in table 2 hereafter.

The invention formula was prepared following a conventionally known method for preparing cosmetic compositions.

Example 3: Evaluation of the properties of the cosmetic composition of the invention and a comparative cosmetic composition

The properties of Cosmetic composition 2 according to the invention and Comparative cosmetic composition 2’of example 2 above were evaluated.

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 removability of dust and mildness of the compositions were evaluated.

An instrumental test for pore cleansing was performed. The protocols are as follows:

1. mark an area of 2.2 diameter on the bio-skin (Beaulax, Disc Shape BSP with Skin Print, No. 10A) ；

2. apply Sebollution (small particle and oil to mimic pollution particle and sebum) on the bio-skin in an amount of 1.56 μg/cm²；

3. mix a cleanser with water (water/cleanser ＝ 2: 1 by weight) , apply the mixture on the marked bio-skin area wherein Sebollution is applied in an amount of 2 μg/cm²；

4. massage by fingerstall 10 circles；

5. rinse the bio-skin with water for 10 seconds；

6. take picture using dermascore plus as T0；

7. repeat steps 2 to 6, wherein the cleanser is replaced by Cosmetic composition 2 and Comparative cosmetic composition 2’, respectively, and take pictures as T1；

8. analyze the pictures taken at T0 and T1 by image analysis program, the parameter is occupation percentage of dark pixels.

According to the protocol, Sebollution is a water-in oil-emulsion with 30％by weight of charcoal and iron oxide. The oil phase contains oleic acid and squalene as well.

The cleanser as mentioned above is a conventional cleansing product sold under the name Yuesai Hydrate/Silver Ear Water-Hold Cleansing Milk.

The removability was calculated using the following equation:

The mildness of the compositions was evaluated using zein test. Zein is a yellow corn protein, similar to keratin present in the skin, with limited solubility in water. It is denatured (solubilized) by the surfactants. The ability of surfactants to denature and solubilize zein has been linked to their skin-irritation potential. The absorption correlates with the solubility of the zein protein which in turn can be considered as a measure of the irritation potential or the harshness of a composition. The harshness of the analyzed compositions was graded and compared using a 1.5 ％solution of sodium laurate sulfate (SLS) as a positive control. The harshness data for the samples is expressed in terms of percentage of the SLS score.

Harshness level:

0-10％: very mild

10-20％: mild

20-50％: a little harsh

50-100％: harsh cleanser

The results of the evaluations are as follows:

The results show that Cosmetic composition 2 of the invention allows a much higher removability of dust than Comparative cosmetic composition 2’. Moreover, Cosmetic composition 2 of the invention is stable, and is gentle to the skin.

Claims

A composition comprising, in an aqueous phase:

a) a copolymer of a C₁₀-C₃₀ alkyl acrylate and of acrylic or methacrylic acid, crosslinked with an allyl ether of sucrose or an allyl ether of pentaerythritol； and

b) wax beads having a median particle size by volume Dv50 ranging from 50 micrometers to 300 micrometers, and wherein said wax has a melting point greater than or equal to 60℃.
The composition of claim 1, wherein the copolymer a) is present in an amount ranging from 0.1％ to 1％ by weight of the total weight of the composition.
The composition of claim 1 or 2, wherein the wax beads b) are present in an amount ranging from 1％ to 30％ by weight of the total weight of the composition.
The composition of any one of claims 1 to 3, wherein the aqueous phase is present in an amount ranging from 70％ to 99％ by weight of the total weight of the composition.
The composition of any one of the claims 1 to 4, wherein the aqueous phase comprises water and at least one organic solvent miscible with water.
The composition of claim 5, wherein the organic solvent miscible with water is selected from the group consisting of monoalcohols having from 2 to 6 carbon atoms； polyols having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, and preferentially having from 2 to 6 carbon atoms； glycol ethers having from 3 to 16 carbon atoms； and mixtures thereof.
The composition of any one of the claims 5 or 6, wherein the aqueous phase comprises water and a polyol, preferably glycerol or propylene glycol, or a monoalcohol, preferably ethanol.
The composition of any one of claims 1 to 7, wherein the wax having a melting point greater than or equal to 60℃ is selected from the group consisting of beeswax, candelilla wax, carnauba wax, C_30-45 alkyl dimethicone and the silicone compound of the following formula:

[CH₃CH₂CH₂SiO_3/2] _x [R (CH₃) ₂SiO_1/2] _y

wherein R is – (CH₂) _nCH₃, and n is an integer from 30 to 45.
The composition of any one of claims 1 to 8, wherein the wax beads b) have a median particle size by volume Dv50 ranging from 100 micrometers to 200 micrometers.
A cosmetic composition for cleansing and/or exfoliating the keratin materials, in particular the skin, comprising the composition of any one of claims 1 to 9, and at least one surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, amphoteric surfactants, zwitterionic surfactants and their mixtures.
The cosmetic composition of claim 10, wherein it further comprises at least one additive selected from the group consisting of thickeners, colorants and preservatives.
The cosmetic composition of claim 10 or 11, wherein the amount of surfactant (s) ranges from 0.1％ to 30％ by weight, preferably from 5％ to 25％ by weight, relative to the total weight of the composition.
A process for preparing the composition according to any one of claims 1 to 9, comprising the following steps:

i) dispersing the copolymer a) in the aqueous phase, and heating the dispersion to a temperature greater than 60℃；

ii) melting the wax having a melting point greater than or equal to 60℃, and adding it to the heated dispersion obtained in i) , so as to obtain a mixture；

iii) homogenizing the mixture obtained in ii) so as to obtain the targeted bead size； and

iv) cooling while stirring the mixture obtained in iii) so as to achieve wax beads.
A method for cleansing and/or exfoliating the keratin materials, in particular the skin, comprising the application to the keratin materials, in particular the skin, of the cosmetic composition of any one of claims 10 to 12.
Use of the cosmetic composition of any one of claims 10 to 12 for cleansing and/or exfoliating keratin materials, in particular the skin.