WO2018103066A1

WO2018103066A1 - Skin care composition

Info

Publication number: WO2018103066A1
Application number: PCT/CN2016/109173
Authority: WO
Inventors: Kun Yun
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2016-12-09
Filing date: 2016-12-09
Publication date: 2018-06-14
Anticipated expiration: 2019-06-09
Also published as: CN110573130B; CN110573130A

Abstract

A composition comprising, in an aqueous phase: a) at least one polysaccharide chosen from gums; b) at least one neutralized polyacrylic acid; c) greater than or equal to 0.1％ by weight, relative to the total weight of the composition, of a polymer comprising at least one monomer of 2-acrylamido-2-methylpropanesulfonic acid; and d) at least one C ₂-C ₆ polyols．

Description

SKIN CARE COMPOSITION

The present invention relates to a composition, in particular a cosmetic or dermatological composition for caring for the skin.

More specifically the present invention relates to a composition, in particular a cosmetic or dermatological composition, having a low amount, in particular free of preservatives and good stability as well as cosmetic properties.

More particularly, the present invention relates to a composition for caring for the skin, substantially free of preservative, in particular free of paraben.

PRIOR ART

It has always been an ultimate goal of the cosmetic formulation to deliver to the consumers high efficient products with cosmetic properties such as hydration, moisturizing, whitening, and so on.

Among all the compositions for caring the skin, masks are known to have high efficacy on the skin. As a result, a market growth of mask cosmetic products was seen.

Conventionally, the masks are grouped to three main categories: tissue masks, the dominant and most developed category； leave-on masks without tissue, such as sleeping masks used at night； and rinse-off masks without tissue, such as the clay mask for cleansing of the skin.

Various types of conventional mask products, with or without tissues, provide good sensory to the skin, the good sensory including moisturizing, hydration, and freshness, thanks to the occlusive properties of these types of products.

Despite the above mentioned properties, there are drawbacks of these products. Consumers experience an unpleasant sensitive feeling after application of the masks. The mask products are normally applied on the skin with a relative long time period. It is possible that the composition can cause sensitive feeling due to the relatively long-term application.

Efforts have been made to formulate mask compositions caring for the skin, with mildness skin sensory after application. In particular, the amount of preservatives was reduced in order to obtain mild cosmetic mask products.

To that end, sterilization procedures were implemented during preparation of such compositions. Mentions can be made to the conventionally available sterilization processes such as heating sterilization.

However, the inventors found that not all compositions can easily be sterilized. Notably some compositions cannot be really sterilized as, upon sterilization, and in particular upon steam sterilization, their viscosity degrades, i.e. the dynamic viscosity of the composition is affected by the sterilization.

Accordingly, there is a need to develop compositions, in particular a cosmetic or dermatological composition, which can undergo sterilization, and in particular steam sterilization.

Moreover, there is a need to develop compositions that provide to the skin mildness feeling after application, and meanwhile undergo sterilization process, without an unacceptable change in viscosity.

Moreover, such compositions are expected to have good cosmetic properties, such as hydration, moisturizing, or fresh feelings after application.

AIMS OF THE INVENTION

The present invention aims to provide a solution to the above mentioned problems.

More particularly, the invention aims to solve the technical problem consisting of providing a composition, in particular a cosmetic or dermatological composition, having a mild feeling after application, in particular having a mild feeling after application as a mask composition, i.e., long-term application on the skin, such as 5 to 15 minutes of application.

One aim of the present invention is to solve the technical problem consisting of providing a composition, in particular a cosmetic or dermatological composition, having a low amount of preservatives. In particular, the composition is essentially free of preservatives, and more particularly free of paraben.

One preferred aim of the present invention is to solve the technical problem consisting of providing a composition, in particular a cosmetic or dermatological composition, having together mildness feeling after application and a low amount of preservatives, or preferably free of preservatives, in particular free of paraben.

One aim of the present invention is to solve the technical problem consisting of providing a composition, in particular a cosmetic or dermatological composition, forming a mask on a keratin material and especially skin, and providing mildness feeling after application with a low amount, or essentially free of preservative compounds, said composition being stable upon sterilization process.

Moreover, the composition as mentioned above provides to the keratin materials, in particular the skin, a good cosmetic properties, and in particular good hydration and moisturizing properties.

Another aim of the present invention is to solve the technical problem consisting of providing a composition, in particular a cosmetic or dermatological composition, which present optimized concentration for optimal stability, cosmetic or dermatological benefit and stable upon sterilization process.

DESCRIPTION OF THE INVENTION

The Applicant has now discovered that it is possible to solve the above technical problems by providing a composition comprising, in an aqueous phase:

a) at least one polysaccharide chosen from gums；

b) at least one neutralized polyacrylic acid；

c) greater than or equal to 0.1％by weight, relative to the total weight of the composition, of a polymer comprising at least one monomer of 2-acrylamido-2-methylpropanesulfonic acid； and

d) at least one C₂-C₆ polyols.

The present invention thus relates to such compositions.

In particular, it has been discovered that prior art compositions which do not comprise the combination of neutralized polyacrylic acids, and

polymers are not appropriate for sterilization process.

Typically, the dynamic viscosity of prior art compositions drops upon sterilization, wherein pressure and /or heat were applied. Such a drop in dynamic viscosity is unwanted as the dynamic viscosity becomes too low for the intended use. Typically, the sterilization of a commercial mask composition, leads the viscosity after sterilization to decrease: the compositions become more liquid.

It was found that a composition according to the invention comprising gum (s) , neutralized polyacrylic acid (s) , and polymer (s) comprising at least one monomer being acrylamido-2-methylpropanesulfonic acid, and C₂-C₆ polyols overcome the above recited technical problems.

The present invention also relates to cosmetic process for caring and/or making up a keratin material, comprising the application, to the surface of said keratin material, of at least one composition according to the present invention, wherein said keratin material is preferably skin, in particular face.

For the purpose of the present invention, the viscosity of the composition is measured. The viscosity of a composition of the invention may be measured via any process known to those skilled in the art, and especially according to the following conventional process. The measurement can be carried out at 25℃ using a Rheomat 180 viscometer equipped with a spindle rotating at 200 rpm. Those skilled in the art may select the spindle for measuring the viscosity from the spindles M1, M2, M3 and M4 on the basis of their general knowledge, so as to be able to perform the measurement.

By “stable upon sterilization” , we intend to mean that the composition of the present invention undergoes the sterilization process without an undesired huge decrease in viscosity. In particular, such a decrease is not acceptable when greater than 35％.

By “keratin materials” we intend to mean human keratin materials and more specifically skin.

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

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" .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Gum (s)

The composition of the present invention comprises at least one gum.

According to an embodiment, the gums that are suitable for the present invention, are xanthan gum, gellan gum, guar gum and nonionic derivatives thereof (hydroxypropyl guar) , gum arabic, konjac gum or mannan gum, gum tragacanth, ghatti gum, karaya gum, locust bean gum, agar gum, scleroglucan gums and mixtures thereof.

Examples that may be mentioned include the xanthan gum sold under the name

CG-T by the company CP Kelco, gellan gum sold under the name

CG LA by the company CP Kelco, guar gum sold under the name Jaguar HP

by the company Rhodia； mannan gum and konjac

(1％glucomannan) sold by the company GfN.

Preferably, the gum that is preferred in the present invention is xanthan gum. Xanthan gum is an anionic polysaccharide composed of a β- (1→4) -D-glucopyranose glucan backbone with side chains of (1→3) -α-D-mannopyranose- (2→1) -β-D-glucuronic acid- (4→1) -β-D-mannopyranose on alternating residues. Xanthan gum is designed by CAS number 11138-66-2.

According to a preferred embodiment, the gum is present in an amount ranging from 0.01％to 3％by weight, preferably from 0.05％to 1％by weight, more preferably from 0.1％to 0.5％by weight, relative to the total weight of the composition.

Neutralized polyacrylic acid (s)

The composition of the present invention comprises at least one neutralized polyacrylic acid.

Suitable neutralized polyacrylic acids for use in the present invention include, but are not limited to, salts of polyacrylic acid. These are anionic polyelectrolytes with negatively charged carboxylic groups in the main chain.

Examples thereof include the sodium, potassium, lithium and ammonium neutralized salts of polyacrylic acid.

The most preferred neutralized polyacrylic acid is sodium polyacrylate.

In one preferred embodiment, said polyacrylate is sodium polyacrylate is designed by CAS number 9003-04-7. Sodium polyacrylate is for example marketed by Sigma-Aldrich, or COSMEDIA SP sold by the company BASF.

The amount of neutralized polyacrylic acid may range, for example, from 0.01％to 3％by weight, preferably from 0.05％to 1％by weight, more preferably from 0.1％to 0.5％by weight, relative to the total weight of the composition.

Polymer (s)

The composition of the present invention comprises at least one polymer comprising at least one monomer being acrylamido-2-methylpropanesulfonic acid

(or

polymers) .

In particular, the

polymers in accordance with the invention are crosslinked or non-crosslinked homopolymers or copolymers comprising at least the acrylamido-2-methylpropanesulfonic acid

monomer, in a form partially or totally neutralized with a mineral base other than ammonia, such as sodium hydroxide or potassium hydroxide.

They are preferably totally neutralized or virtually totally neutralized, i.e. at least 90％neutralized.

These

polymers according to the invention may be crosslinked or non-crosslinked.

When the polymers are crosslinked, the crosslinking agents may be chosen from the polyolefinically unsaturated compounds commonly used for the crossli nking of polymers obtained by free-radical polymerization. Examples of crosslinking agents that may be mentioned include divinylbenzene, diallyl ether, dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethylene glycol divinyl ether, hydroquino ne diallyl ether, ethylene glycol or tetraethylene glycol di (meth) acrylate, trimethylolpropane triacrylate, methylenebisacrylamide, methylenebismethacrylamide, triallylamine, triallyl cyanurate, diallyl maleate, tetraallylethylenediamine, tetraallyloxyethane, trimethylolpropane diallyl ether, allyl (meth) acrylate, allylic ethers of alcohols of the sugar series, or other allylic or vinyl ethers of polyfunctional alcohols, and also allylic esters of phosphoric and/or vinylphosphonic acid derivatives, or mixtures of these compounds.

According to one embodiment of the invention, the crosslinking agent is chosen from methylenebis-acrylamide, allyl methacrylate and trimethylolpropane triacrylate (TMPTA) . The degree of crosslinking generally ranges from 0.01 mol％to 10 mol％and more particularly from 0.2 mol％to 2 mol％relative to the polymer.

The

polymers in accordance with the invention are water-soluble or water-dispersible. In this case they are:

- either "homopolymers" comprising only

monomers and, if they are crosslinked, one or more crosslinking agents such as those defined above；

- or copolymers obtained from

and from one or more hydrophilic or hydrophobic ethylenically unsaturated monomers and, if they are crosslinked, one or more crosslinking agents such as those defined above. When the said copolymers comprise hydrophobic ethylenically unsaturated monomers, these monomers do not comprise a fatty chain and are preferably present in small amounts.

For the purposes of the present invention, the term "fatty chain" means any hydrocarbon-based chain containing at least 7 carbon atoms.

The term "water-soluble or water-dispersible" means polymers which, when introduced into an aqueous phase at 25℃, to a mass concentration equal to 1％, make it possible to obtain a macroscopically homogeneous and transparent solution, i.e. a solution that has a maximum light transmittance value, at a wavelength equal to 500 nm, through a sample 1 cm thick, of at least 60％and preferably of at least 70％.

The "homopolymers" according to the invention are preferably crosslinked and neutralized, and they may be obtained according to the preparation process comprising the following steps:

(a) the monomer such as

in free form is dispersed or dissolved in a solution of tert-butanol or of water and tert-butanol；

(b) the solution or dispersion of monomer obtained in (a) is neutralized with one or more mineral or organic bases, preferably ammonia NH₃, in an amount making it possible to obtain a degree of neutralization of the sulfonic acid functions of the polymer ranging from 90％to 100％；

(c) the crosslinking monomer (s) is (are) added to the solution or dispersion obtained in (b) ；

(d) a standard free-radical polymerization is performed in the presence of free-radical initiators at a temperature ranging from 10 to 150℃； the polymer precipitates in the solution or dispersion based on tert-butanol.

The

homopolymers according to the invention are preferably optionally crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid homopolymers, for instance the poly (2-acrylamido-2-methylpropanesulfonic acid) sold by the company Clariant under the name Hostacerin

(CTFA name: ammonium polyacryldimethyltauramide) .

The water-soluble or water-dispersible AMPS copolymers according to the invention contain preferably water-soluble ethylenically unsaturated monomers, hydrophobic monomers or mixtures thereof.

The water-soluble comonomers may be ionic or nonionic.

Among the ionic water-soluble comonomers, examples that may be mentioned include the following compounds and the salts thereof:

- (meth) acrylic acid,

- styrenesulfonic acid,

- vinylsulfonic acid and (meth) allylsulfonic acid,

- vinylphosphonic acid,

- maleic acid,

- itaconic acid,

- crotonic acid,

- the water-soluble vinyl monomers of formula (A) below:

in which:

- R₁ is chosen from H, -CH₃, -C₂H₅ and -C₃H₇

- X₁ is chosen from:

- alkyl ethers of -OR₂ type in which R₂ is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms, substituted with at least one sulfonic (-SO₃-) and/or sulfate (-SO₄-) and/or phosphate (-PO₄H₂-) group.

Among the nonionic water-soluble comonomers, examples that may be mentioned include:

- (meth) acrylamide,

- N-vinylacetamide and N-methyl-N-vinylacetamide,

- N-vinylformamide and N-methyl-N-vinylformamide,

- maleic anhydride,

- vinylamine,

- N-vinyllactams comprising a cyclic alkyl group containing 4 to 9 carbon atoms, such as n-vinylpyrrolidone, N-butyrolactam and N-vinylcaprolactam,

- vinyl alcohol of formula CH₂＝CHOH,

- the water-soluble vinyl monomers of formula (B) below:

in which:

- R₁₅ is chosen from H, -CH₃, -C₂H₅ and -C₃H₇

- X₂ is chosen from:

- alkyl ethers of -OR₁₆ type in which R₁₆ is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbons, optionally substituted with a halogen atom (iodine, bromine, chlorine or fluorine) ； a hydroxyl group (-OH) ； ether.

Mention is made, for example, of glycidyl (meth) acrylate, hydroxyethyl methacrylate and (meth) acrylates of ethylene glycol, of diethylene glycol or of polyalkylene glycol.

Among the fatty-chain-free hydrophobic comonomers, examples that may be mentioned include:

- styrene and its derivatives, such as 4-butylstyrene, α-methylstyrene and vinyltoluene,

- vinyl acetate of formula CH₂＝CH-OCOCH₃；

- vinyl ethers of formula CH₂＝CHOR in which R is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbons；

- acrylonitrile,

- caprolactone,

- vinyl chloride and vinylidene chloride,

- silicone derivatives, which lead to silicone polymers after polymerization, such as methacryloxypropyltris (trimethylsiloxy) silane and silicone methacrylamides,

- the hydrophobic vinyl monomers of formula (C) below:

in which:

- R₂₃ is chosen from H, -CH₃, -C₂H₅ and -C₃H₇

- X₃ is chosen from:

- alkyl ethers of -OR₂₄ type in which R₂₄ is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms.

Mention is made, for example, of methyl methacrylate, ethyl methacrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl acrylate and isobornyl acrylate and 2-ethylhexyl acrylate.

The water-soluble or water-dispersible

polymers of the invention preferably have a molar mass ranging from 50 000 g/mol to 10 000 000 g/mol, preferably from 80 000 g/mol to 8 000 000 g/mol and even more preferably from 100 000 g/mol to 7 000 000 g/mol.

Examples of water-soluble or water-dispersible AMPS homopolymers in accordance with the invention that may be mentioned include crosslinked or non-crosslinked polymers of sodium acrylamido-2-methylpropanesulfonate, such as the polymer used in the commercial product Simulgel^TM 800 (CTFA name: Sodium Polyacryloyldimethyltaurate) .

Examples of water-soluble or water-dispersible AMPS copolymers in accordance with the invention that may be mentioned include:

- acrylamide/sodium acrylamido-2-methylpropanesulfonate crosslinked copolymers, such as the copolymer used in the commercial product Sepigel 305 (CTFA name: Polyacrylamide/C₁₃-C₁₄ Isoparaffin/Laureth-7) or the copolymer used in the commercial product sold under the trade name Simulgel^TM 600 (CTFA name: Acrylamide/Sodium Acryloyldimethyltaurate/Isohexadecane/Polysorbate-80) by the company SEPPIC；

- copolymers of AMPS and of vinylpyrrolidone or of vinylformamide, such as the copolymer used in the commercial product sold under the name Aristoflex AVC by the company Clariant (CTFA name: Ammonium Acryloyldimethyltaurate/VP Copolymer) but neutralized with sodium hydroxide or potassium hydroxide；

- copolymers of AMPS and of sodium acrylate, for instance AMPS/sodium acrylate copolymer such as the copolymer used in the commercial product sold under the name Simulgel^TM EG by the company SEPPIC (CTFA name: Acrylamide/Sodium Acryloyldimethyltaurate/Isohexadecane/Polysorbate-80) ；

- copolymers of AMPS and of hydroxyethyl acrylate, for instance AMPS/hydroxyethyl acrylate copolymer, such as the copolymer used in the commercial product sold under the name Simulgel^TM NS by the company SEPPIC (CTFA name: Hydroxyethyl acrylate/Sodium Acryloyldimethyltaurate copolymer (and) Squalane (and) Polysorbate-60) .

The preferred polymers are more particularly sodium acrylamido-2-methylpropanesulfonate homopolymers, such as the homopolymer used in the commercial product Sepigel^TM 800, and

/hydroxyethyl acrylate copolymers, such as the copolymer used in the commercial product sold under the name Simulgel NS.

According to one particularly preferred form of the invention, the

polymer or copolymer will be used in powder form.

The polymers derived from AMPS may further be those comprising:

- from 80 mol％to 99 mol％of 2-acrylamido-2-methylpropanesulfonic acid

units of formula (3) below:

in which X⁺ is a proton, an alkali metal cation, an alkaline-earth metal cation or an ammonium ion； and

- 1 mol％to 20 mol％and preferably from 1 mol％to 15 mol％of units of formula (4) below:

in which n and p, independently of each other, denote a number of moles and ranges from 0 to 30 and preferably from 1 to 20, with the proviso that n + p is less than or equal to 30, preferably less than 25 and better still less than 20； R₁ denotes a hydrogen atom or a linear or branched C₁-C₆ alkyl radical (preferably methyl) and R₃ denotes a linear or branched alkyl comprising m carbon atoms, with m ranging from 6 to 30 and preferably from 10 to 25.

These polymers according to the invention may be obtained according to the standard free-radical polymerization processes in the presence of one or more initiators such as, for example, azobisisobutyronitrile (AIBN) , azobisdimethylvaleronitrile, 2, 2-azobis [2-amidinopropane] hydrochloride (ABAH ＝2, 2-azoBis- [2-Amidinopropane] hydrochloride) , organic peroxides such as dilauryl peroxide, benzoyl peroxide, tert-butyl hydroperoxide, etc., mineral peroxide compounds such as potassium persulfate or ammonium persulfate, or H₂O₂ optionally in the presence of reducing agents.

The polymers are obtained especially by free-radical polymerization in tert-butanol medium from which they precipitate. Using polymerization in tert-butanol, it is possible to obtain a size distribution of the polymer particles that is particularly favourable for its uses.

The polymerization reaction may be performed at a temperature of between 0 and 150℃, preferably between 20 and 100℃, either at atmospheric pressure or under reduced pressure. It may also be performed under inert atmosphere, and preferably under nitrogen.

It is thus possible to use the polymers prepared from 2-acrylamido-2-methylpropanesulfonic acid

or a sodium or ammonium salt thereof, with an ester of (meth) acrylic acid and:

- of a C₁₀-C₁₈ alcohol oxyethylenated with 8 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₁ oxo alcohol oxyethylenated with 8 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₁ oxo alcohol oxyethylenated with 7 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₂-C₁₄ alcohol oxyethylenated with 7 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₂-C₁₄ alcohol oxyethylenated with 9 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₂-C₁₄ alcohol oxyethylenated with 11 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₆-C₁₈ alcohol oxyethylenated with 8 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₆-C₁₈ alcohol oxyethylenated with 11 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₆-C₁₈ alcohol oxyethylenated with 15 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₆-C₁₈ alcohol oxyethylenated with 20 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₆-C₁₈ alcohol oxyethylenated with 25 mol of ethylene oxide (Genapol

from the company Clariant) ,

- of a C₁₈-C₂₂ alcohol oxyethylenated with 25 mol of ethylene oxide,

- of a C₁₆-C₁₈ iso-alcohol oxyethylenated with 25 mol of ethylene oxide.

According to one preferred embodiment, the polymer is a copolymer of

and of a C₁₆-C₁₈ alcohol methacrylate comprising from 6 to 25 mol of oxyethylene groups, obtained from methacrylic acid or a methacrylic acid salt and from a C₁₆-C₁₈ alcohol oxyethylenated with 6 to 25 mol of ethylene oxide.

The polymer may also be a copolymer of

and of a C₁₂-C₁₄ alcohol methacrylate comprising from 6 to 25 mol of oxyethylene groups, obtained from methacrylic acid or a methacrylic acid salt and from a C₁₂-C₁₄ alcohol oxyethylenated with 6 to 25 mol of ethylene oxide.

As polymers of

type that are preferred according to the present invention, mention may be made of:

- the non-crosslinked copolymer obtained from 92.65 mol％of

and 7.35 mol％of a C₁₆-C₁₈ alcohol methacrylate comprising 8 oxyethylene groups (Genapol

) ,

- the non-crosslinked copolymer obtained from 91.5 mol％of

and 8.5 mol％of a C₁₂-C₁₄ alcohol methacrylate comprising 7 oxyethylene groups (Genapol

) ,

- the crosslinked copolymer obtained from 96.45 mol％of

and 3.55 mol％of a C₁₆-C₁₈ alcohol methacrylate comprising 25 oxyethylene groups (Genapol

) , the crosslinking agent is trimethylolpropane triacrylate,

- the crosslinked copolymer obtained from

and from a C₂₂ alcohol methacrylate comprising 25 oxyethylene groups； this polymer is sold under the name Aristoflex

by the company Clariant,

- the acrylamide/sodium 2-methyl-2- [ (1-oxo-2-propenyl) amino] -1-propanesulfonate

copolymer such as Simulgel

in the form of an emulsion containing polysorbate 80 as surfactant and containing isohexadecane as fatty phase, sold by the company SEPPIC, or alternatively Simulgel

Simulgel

and Simulgel

sold by the same company.

Simulgel

is described especially in document FR 2 785 801. It is more specifically a reverse latex. The

polyelectrolyte is 2-methyl-2- [ (1-oxo-2-propenyl) amino] -1-propanesulfonic acid partially or totally salified especially in sodium salt or ammonium salt form, to a proportion of from 30 mol％to 50 mol％in the mixture comprising the

and an acrylamide, which is itself in a proportion of 50％to 70％.

For the purpose of the present invention, the preferred polymers derived from

is the optionally crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid homopolymers, for instance the poly (2-acrylamido-2-methylpropanesulfonic acid) sold by the company Clariant under the name Hostacerin

(CTFA name: ammonium polyacryldimethyltauramide) .

According to a preferred embodiment, the amount of the polymer c) may range, for example, from 0.01％to 5％by weight, preferably from 0.1％to 1％by weight, relative to the total weight of the composition.

For the purpose of the present invention, preferably, when adjusting the weight ratio of the above described ingredients, the composition according to the present invention presents good properties both in terms of mildness as well as viscosity after sterilization process. According to a particularly preferred embodiment, the weight ratio of the gum (s) and the sum of neutralized polyacrylic acid and polymer (s) comprising at least one monomer being acrylamido-2-methylpropanesulfonic acid is preferably between 2 and 0.1, preferably between 1.5 and 0.2, more preferably between 1 to 0.4.

C₂-C₆ polyols

The composition of the present invention comprises at least one C₂-C₆ polyol.

According to an embodiment, the C₂-C₆ polyols is selected from the group consisting of glycerin, glycols, or mixtures thereof.

By a C₂-C₆ polyol, it is meant a polyol comprising from 2 to 6 carbon atoms, and at least two hydroxyl groups.

Advantageously, C₂-C₆ glycols can be linear or branched.

Among C₂-C₆ glycols, it can be cited propylene glycol, butylene glycol, pentylene glycol, dipropylene glycol, glycerin, or their mixtures.

Glycerin, also known as glycerol, is propane-1, 2, 3-triol and is designed by CAS number 56-81-5.

A glycol is a vicinal diol, with two hydroxyl groups occupying vicinal positions. Examples of C₂-C₆ glycols include 1, 2-ethanediol or ethylene glycol (designed by CAS number 107-21-1) or propane-1, 2-diol or alpha propylene glycol (designed by CAS number 57-55-6) , or 1, 2-butanediol (designed notably by CAS number 584-03-2) or 2, 3-butanediol (designed notably by CAS number 513-85-9) and any enantiomers thereof.

Preferably, the C₂-C₆ polyol is chosen among propylene glycol, butylene glycol, glycerin, or their mixtures.

In one embodiment, the amount of C₂-C₆ polyol is ranging from 0.001％to 30％by weight, preferably from 0.01％to 20％by weight, more preferably from 5％to 20％by weight, relative to the total weight of the composition.

Preservatives

Preferably, the composition of the present invention comprises, when exists, less than 0.3％by weight of total preservative compounds, relative to the total weight of the composition.

In one embodiment, the composition is essentially free of preservative compounds.

“Essentially free of preservative compounds” means that the composition comprises no usual preservative compounds, such as parabens, or that the composition comprises ingredients which might be used as preservatives, however with the amount much lower than the effective amount known in the prior arts.

Particularly, the composition comprises at most 0.2％by weight, preferably at most 0.1％by weight, of preservative (s) , relative to the total weight of the composition.

In one specific embodiment, the composition of the invention is essentially free of preservative compounds selected from the group consisting of parabens, particularly alkyl parabens such as for example propyl p-hydroxybenzoate (propyl paraben) , methyl p-hydroxybenzoate (methyl paraben) , butyl p-hydroxybenzoate (butyl paraben) and phenoxyethanol.

In one embodiment, the composition comprises no parabens. “No parabens” means that the amount of parabens is below the limit imposed by law or regulations to claim, for example on a packaging, this absence of parabens.

In one embodiment, the composition may additionally comprise one or more other topically acceptable ingredient.

Active ingredient

In one embodiment, the composition may comprise at least one skin care agent and/or at least one cosmetically active ingredient.

Cosmetically active ingredients may be for example selected from the group consisting of oils, humectants, surfactants, structuring agents, sunscreens, film formers, acidifying and/or alkalizing agents, buffering agents, chelating agents, coloring additives, dermatologically active agents, whitening active ingredients, others skin care agents, cosmetically active ingredients, and any combination thereof.

For example, the skin care agent and/or cosmetically active ingredient is selected from the group consisting of whitening agents, anti-oxidants, cleansing agents, free radical scavengers, moisturizers, skin tone altering agents, anti-acne agents, anti-aging agents, anti-wrinkle agents, anti-inflammatory agents, skin texture treatment agents, anti-perspirant agents, aesthetics, anti-bacterial agents, nourishing agents, sebum and/or moisture absorbers and any combination thereof.

In one embodiment, the amount of active ingredient (s) ranges from 0.0001 to 10％, preferably from 0.001 to 10％, and more preferably from 0.01 to 5％by weight relative to the total weight of the composition.

For example, the amount of active ingredient (s) is from 0.1％to 5％by weight relative to the total weight of the composition.

Aqueous phase

The composition according to the invention comprises an aqueous phase. The aqueous phase of the present invention comprises water.

The aqueous phase may also comprise water-miscible organic solvents (at room temperature of 20-25℃) , for instance polyols other than the C₂-C₆ polyols as claimed in the present invention； glycol ethers (especially containing from 3 to 16 carbon atoms) such as mono-, di-or tripropylene glycol (C₁-C₄) alkyl ethers, mono-, di-or triethylene glycol (C₁-C₄) alkyl ethers, and mixtures thereof.

The amount of aqueous phase may range, for example, from 0.1％to 99.9％by weight, preferably from 0.5％to 99％by weight relative to the total weight of the composition.

According to an embodiment, the amount of water in the compositions according to the invention ranges from 20％to 95％by weight, preferably from 30％to 90％by weight, more preferably from 50％to 85％by weight, relative to the total weight of the composition.

Additives/Excipients

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, and so on.

The compositions according to the present invention may also comprise conventional cosmetic additives soluble in the aqueous phase of the composition of the invention chosen in particular organic solvents, ionic or nonionic thickeners, softeners, humectants, additional opacifiers, stabilizers, emollients, silicones, antifoams, fragrances, anionic, cationic, nonionic, zwitterionic or amphoteric surfactants, active agents, fillers, polymers, propellants, acidifying or basifying agents or any other ingredient commonly used in the cosmetic and/or dermatological field.

In one embodiment, the aqueous phase may also contain additives such as water-soluble active ingredients, salts, gelling agents, fillers, water-soluble or water-dispersible polymers, water-soluble dyes, and any mixture thereof.

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

Formulation

The present invention relates to a composition, in particular a cosmetic or dermatological composition, in the form of an aqueous composition.

The present invention relates in particular to a mask, in particular a cosmetic or dermatological mask, essentially free of preservative, and in particular free of paraben.

According to an embodiment, the invention relates to a cosmetic composition for caring for keratin materials, in particular the skin, comprising a composition as described in the present invention, and at least a substrate.

The substrate is conventionally known as tissue masks for caring for the skin. There is no limit to the type of the substrate that can be used in the composition of the present invention.

Therefore according to an embodiment, the present invention relates to a cosmetic composition, in particular a mask for caring for keratin materials, in particular skin, comprising, in an aqueous phase, xanthan gum, sodium polyacrylates, greater than or equal to 0.1％by weight, relative to the total weight of the composition, of a polymer comprising at least one monomer of 2-acrylamido-2-methylpropanesulfonic acid, and at least one C₂-C₆ polyols.

Viscosity

Preferably, the composition of the present invention has a viscosity from 100 mPa·s to 500 mPa·s, more preferably from 200 mPa·s to 400 mPa·s, before the sterilization process.

Preferably, the composition of the present invention has a viscosity of from 120 mPa·s to 500 mPa·s, preferably from 200 mPa·s to 400 mPa·s, after the sterilization process.

The viscosity of a composition of the invention may be measured via the process as described above.

More specifically, the viscosity of the composition according to the invention is measured at 25℃, using a ProRheo R180 viscometer equipped with a spindle M2 rotating at 200 rpm from the company Prorheo.

When the above measurement is applied, the viscosity is presented using the unit UD. The following equation is then applied to obtain the viscosity in the unit of mPa·s (mPascal per second) :

Viscosity (mPa·s) ＝ 10.6*UD (this equation just applied to M2 spindle)

Stability upon sterilization

The composition of the present invention is stable upon sterilization.

For the purpose of the present invention, the composition undergoes sterilization process without an unacceptable decrease in viscosity.

In particular, such a decrease is less than or equal to 35％, preferably less than or equal to 30％, more particular less than or equal to 20％.

％viscosity decrease ＝ (viscosity before sterilization –viscosity after sterilization) / viscosity before sterilization × 100％

Process for preparing the composition

One specific advantage of the composition of the invention is to allow the possibility to sterilize the composition without negatively affecting the stability of the composition.

By “stability” it is referred in the present invention in this context in particular to the stability of the dynamic viscosity of the composition upon sterilization.

Sterilization refers in particular to any process that eliminates, removes, kills, or deactivates from a composition microorganisms and pathogens (including viruses) .

In one embodiment, sterilization is selected from the group consisting of heat sterilization, chemical sterilization, irradiation sterilization, pressure sterilization, and filtration sterilization.

Heat sterilization includes notably steam, dry heat, flaming, incineration, tyndallization, sterilization with glass beads.

Chemical sterilization includes notably sterilization with Ethylene oxide, Nitrogen dioxide, Ozone, Glutaraldehyde and formaldehyde, Hydrogen peroxide, Peracetic acid.

Radiation sterilization includes notably Non-ionizing radiation sterilization and Ionizing radiation sterilization.

In one embodiment, heat sterilization is steam sterilization. A widely used method for heat sterilization is the autoclave, generally called steam sterilizer. Typically the composition to be sterilized is placed in an autoclave which is heated to a temperature in the range 121-34℃ under pressure in the presence of steam (water steam) . In generally steam sterilization requires heat treatment at above 121℃ for several minutes, typically for at least 15 minutes.

The present invention relates to composition obtainable according to such a sterilization process.

Contrary to compositions of the invention, compositions of the prior art cannot tolerate heat sterilization, especially in autoclave. Upon heat sterilization in autoclave the prior art compositions become very liquid (the dynamic viscosity diminishes significantly) .

Method and use

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, a spatula, or by spraying, and can be removed by rinsing with water or using a gentle detergent.

In one particular embodiment, after application on skin, the composition forms a mask when topically applied, especially after application on human skin.

Typically, the mask forms a film or sheet.

In one embodiment, the composition forms a skin mask.

In one embodiment, the composition forms a face mask.

In one embodiment, the composition forms a film or sheet.

In one embodiment, the composition forms a leave on mask.

In one particular embodiment, the composition is used to prepare a solid applicator body.

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

The composition of the present invention can be used for a cosmetic process, such as a cosmetic process or method, for making up/caring for the keratin materials, such as the skin, in particular the face and the lips, by being applied to the skin, especially the face.

The present invention also relates to a use of the composition according to the present invention, for making up/caring for the skin, especially for the face.

Advantageously, the composition of the invention is a skin mask providing a skin benefit.

Among skin benefit, in one embodiment the composition limits the skin sensitivity.

Among skin benefit, in one embodiment the composition has better skin finish in terms of reflection, softness, plump. The composition of the invention has a better consumer appreciation than prior art compositions.

The composition of the present invention is stable over time.

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

The examples that follow are aimed at illustrating the compositions and processes according to this invention, but are not in any way a limitation of the scope of the invention.

EXAMPLES

Example 1 –Formulations of invention and comparative formulas

Comparative formulas B to D do not comprise one of the ingredients a) to c) , respectively.

The invention and comparative formulas were prepared following the steps of:

Heat phase A to 80℃ until totally dissolved；

Mix phase B into phase A under 80℃, homogenize until uniform；

Add phase C to the mixture obtained above and cool down the mixture till 40℃；

Add phase D to the mixture obtained above, and mix until dissolved.

Example 2 –Sterilization of compositions

In this example, the viscosity change of the invention and comparative formulas after heat sterilization in an autoclave was measured.

The above results supports that the invention formula has the expected viscosity before and after sterilization, and is stable upon sterilization process. On the other hand, none of the comparative formulas is acceptable, in view of their viscosities, and/or their stabilities upon sterilization.

Example 3 –Consumers tests

The invention and comparative formulas (after sterilization) were then applied on the facial skin of 5 consumers as a leave on mask product with a conventionally available tissue substrate sold by the company FJNF Co., Ltd., respectively (28 g per tissue substrate) . The skin feelings after application as well as the cosmetic properties were evaluated by the consumers.

It is observed that the comparative formulas B, C, and D cannot be used as mask compositions. The formulas are dripping from the tissues and are not easy to apply on the skin. The viscosity change has a negative impact on the cosmetic performance as well as the skin feeling of the formulas.

On the other hand, consumers find that the invention formula A provides to the skin a very good mildness feeling after application as a leave on tissue mask, and a very hydrating and moisturizing feeling is perceived by the consumers.

Claims

-A composition comprising, in an aqueous phase:

a) at least one polysaccharide chosen from gums；

b) at least one neutralized polyacrylic acid；

c) greater than or equal to 0.1％ by weight, relative to the total weight of the composition, of a polymer comprising at least one monomer of 2-acrylamido-2-methylpropanesulfonic acid； and

d) at least one C₂-C₆ polyols.
-The composition according to claim 1, wherein said C₂-C₆ polyols is selected from the group consisting of glycerin, glycols, or mixtures thereof.
-The composition according to claim 1 or 2, wherein the C₂-C₆ polyols is present in an amount ranging from 0.001％ to 30％ by weight, preferably from 0.01％ to 20％ by weight, more preferably from 5％ to 20％ by weight, relative to the total weight of the composition.
-The composition according to any one of the preceding claims 1 to 3, wherein said composition comprises less than 0.3％ by weight of total preservative compounds relative to the total weight of the composition； preferably the composition is essentially free of preservative compounds selected from the group consisting of parabens.
-The composition according to any one of the preceding claims 1 to 4, wherein the gum is selected from the group consisting of xanthan gum, gellan gum, guar gum and nonionic derivatives thereof, gum arabic, konjac gum or mannan gum, gum tragacanth, ghatti gum, karaya gum, locust bean gum, agar gum, scleroglucan gums, and mixtures thereof； preferably xanthan gum.
-The composition according to any one of the preceding claims 1 to 5, wherein the the gum is present in an amount ranging from 0.01％ to 3％ by weight, preferably from 0.05％ to 1％ by weight, more preferably from 0.1％ to 0.5％ by weight, relative to the total weight of the composition.
-The composition according to any one of the preceding claims 1 to 6, wherein the neutralized polyacrylic acid is sodium polyacrylate.
-The composition according to any one of the preceding claims 1 to 7, wherein the neutralized polyacrylic acid is present in an amount ranging from 0.01％ to 3％ by weight, preferably from 0.05％ to 1％ by weight, more preferably from 0.1％ to 0.5％ by weight, relative to the total weight of the composition.
-The composition according to any one of the preceding claims 1 to 8, wherein the polymer comprising at least one monomer of 2-acrylamido-2-methylpropanesulfonic acid is selected from the group consisting of crosslinked or non-crosslinked homopolymers or copolymers comprising at least the acrylamido-2-methylpropanesulfonic acid
monomer, in a form partially or totally neutralized with a mineral base other than ammonia, such as sodium hydroxide or potassium hydroxide； preferably selected from optionally crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid homopolymers, more preferably the polymer is poly (2-acrylamido-2-methylpropanesulfonic acid) .
-The composition according to any one of the preceding claims 1 to 9, wherein the polymer c) is present in an amount ranging from 0.01％ to 5％ by weight, preferably from 0.1％ to 1％ by weight, relative to the total weight of the composition.
-The composition according to any one of the preceding claims 1 to 10, wherein the weight ratio of the gum (s) a) and the sum of neutralized polyacrylic acid b) and polymer (s) c) comprising at least one monomer being acrylamido-2-methylpropanesulfonic acid is preferably between 2 and 0.1, preferably between 1.5 and 0.2, more preferably between 1 to 0.4.
-The composition according to any one of the preceding claims 1 to 11, wherein the composition presents a viscosity before sterilization ranging from 100 to 500 mPa·s, preferably from 200 to 400 mPa·s, and a viscosity after sterilization of from 120 mPa·s to 500 mPa·s, preferably from 200 mPa·sto 400 mPa·s.
-A cosmetic composition for caring for keratin materials, in particular the skin, comprising a composition of any one of the preceding claims 1 to 12, and at least a substrate.
-A cosmetic process for caring and/or making up a keratin material, comprising the application, to the surface of said keratin material, of at least one composition according to any one of claims 1 to 13, wherein said keratin material is preferably skin, in particular face.