WO2022007341A1

WO2022007341A1 - Face cleansing composition containing amino acid surfactants

Info

Publication number: WO2022007341A1
Application number: PCT/CN2020/138340
Authority: WO
Inventors: Heliang DU; Yan Li
Original assignee: Beiersdorf Ag; Nivea (Shanghai) Co. Ltd.
Priority date: 2020-07-06
Filing date: 2020-12-22
Publication date: 2022-01-13
Also published as: CN112190494A; CN115884745A; CN112190494A8

Abstract

The present invention relates to a cosmetic cleansing composition comprising an amino acid surfactant system consisting of sodium alkyl glycinate and potassium alkyl glycinate, and glycerol in an amount greater than 25 %by weight, referring to the total weight of the composition. The composition has a consistency being adapted to an easy dispensing from a tube, has a good cleansing efficiency and foam performance, and is still mild to the skin.

Description

Face Cleansing Composition containing Amino Acid Surfactants

Technical field

The present invention describes a cosmetic cleansing composition, particularly a face cleansing composition based on an amino acid surfactant system. The composition may smoothly be dispensed from the packaging device, particularly a tube. Upon foaming the composition builds up a dense and creamy foam. Moreover, the skin is cleansed in an effective way without being irritated.

Background art

In general, cleansing products are supposed to cleanse the skin and hair. Cleansing products for the skin are primarily used to remove dirt from the skin surface. External solid or liquid components, which came into contact with the skin and were deposited thereupon, or components applied to the skin, are part of the dirt on the skin, which is to be removed. Furthermore, the dirt on the skin also includes excess skin lipids and dead cells. By the aid of surfactants in the cleansing compositions, the components of the dirt are solubilized and removed from the surface of the skin during rinsing off.

Cleansing compositions intended for face cleansing have to meet special requirements. As the skin of the face is a very sensitive part of the skin, the eye area and the eyes being even more sensitive, cleansing compositions for face cleansing have to be compatible to the skin of the face and the eyes. Furthermore, the compositions have to be distributed on the skin easily, without the necessity of intense rubbing, which may lead to skin irritations.

Additionally, cleansing compositions, which are intended to be used by men, have to be efficient in cleansing while easy to handle. Analyzing consumer tests and questionnaires, it became apparent that men preferred cleansing compositions provided in a tube.

Hence, there was a need to provide mild cleansing compositions, which are made available in tubes. For this purpose, the composition must have a texture and consistency, which allows an easy dispensing from said packaging device. Moreover, the compositions have to be stable, at least over the shelf storage time.

To meet the criterion of mildness amino acid surfactants may be incorporated in the cleansing compositions.

The use of amino acid surfactants in cleansing compositions is described in prior art.

WO 2019/114274 A1 describes a shaving cream, which may be used for cleansing as well. This composition contains an amino acid surfactant system consisting of sodium lauroyl glutamate and sodium cocoyl glycinate and glycerol in an amount 2 to 10 parts.

CN 107773456 A discloses a facial cleanser also containing sodium lauroyl glutamate and sodium cocoyl glycinate and glycerin in an amount of 5 %.

CN 111671659 A describes a cleansing cream comprising sodium cocoyl glycinate and 10 to 20%glycerin.

CN 111467290 A discloses an amino acid facial cleanser containing octyldodecanol lauroyl glutamate and potassium cocoyl glycinate.

The problem to be solved by the present invention is to provide a cleansing composition, particularly for face cleansing, which has a consistency being adapted to an easy dispensing from a tube, has a good cleansing efficiency and foam performance, and is still mild to the skin.

Surprisingly, the problem was solved by a cosmetic cleansing composition containing

- an amino acid surfactant system consisting of sodium alkyl glycinate and potassium alkyl glycinate,

- glycerol in an amount greater than 25 %by weight, referring to the total weight of the composition.

Likewise, preferably, no further amino acid surfactants are contained, even more preferably no further anionic surfactants are contained in the composition of the present invention.

In the composition of the present invention the amino acid surfactant system consisting of sodium alkyl glycinate and potassium alkyl glycinate is contained in an amount of 10 to 30%by weight, preferably 12 to 20%by weight, referring to the total weight of the composition and referring to the active content of each surfactant. Sodium alkyl glycinate is contained in an amount of 1 to 5%by weight, preferably 3 to 4%by weight, referring to the total weight of the composition and referring to the active content. Potassium alkyl glycinate is contained in an amount of 8 to 25%by weight, preferably 10 to 20%by weight, referring to the total weight of the composition and referring to the active content.

The alkyl residue of sodium alkyl glycinate and potassium alkyl glycinate may comprise 6 to 22 carbon atoms. The alkyl residue may consist of a definite number of carbon atoms or may be a mixture, which may be obtained from natural oils or fats, like palm oil, soybean oil and coconut oil. According to the present invention it is preferred, if the alkyl residues are derived from fatty acids contained in the triglycerides of coconut oil. Hence, it is preferred, if sodium cocoyl glycinate and potassium cocoyl glycinate are contained in the composition of the present invention.

Advantageously, sodium alkyl glycinate and potassium alkyl glycinate are contained in specific weight ratio, namely a weight ratio between sodium alkyl glycinate and potassium alkyl glycinate in the range of 3: 1 to 1: 10, preferably 2: 1 to 1: 4, and more preferably 1: 1 to 1: 2.3.

The composition of the present invention is an aqueous composition, preferably containing 5 to 35%by weight, more preferably 10 to 30%by weight water, referring to the total weight of the composition.

According to the present invention glycerol has to be present in an amount greater than 25 %by weight, referring to the total weight of the composition. Preferably, glycerol is contained in an amount of 25 to 40%by weight, more preferably 30 to 39%by weight, referring to the total weight of the composition. In the composition according to the present invention the high amount of glycerol contributes to build up a structure in the composition and thereby helps to provide a suitable consistency, which allows a smooth dispensing out of the tube.

Additionally, one or more thickening agent (s) may be contained in the composition according to the present invention. Thickening agents may also be referred to as hydrocolloids". Hydrocolloids are macromolecules being build up in a largely linear manner; however intramolecular and intermolecular interactions enable the formation of a network-like structure. Hydrocolloids are partially water-soluble natural or synthetic polymers that form gels or viscous solutions in aqueous systems. They increase the viscosity of the water either by binding water molecules (hydration) or by absorbing water in spaces in the interacting macromolecules, thereby restricting the mobility of the water. Such water-soluble polymers represent a large group of chemically very different natural and synthetic polymers, the common feature of which is their solubility or swellability in water or aqueous media. This property is due to a sufficient number of hydrophilic groups and only a limited crosslinking. The hydrophilic groups can be nonionic, anionic or cationic in nature.

The group of cosmetically and dermatologically relevant hydrocolloids can be divided into:

- organic, natural compounds such as agar-agar, carrageenan, tragacanth, gum arabic, alginates, pectins, polyoses, guar flour, carob gum, starch, dextrins, gelatine, casein,

- organic, modified natural substances, such as carboxymethyl cellulose and other cellulose ethers, hydroxyethyl and -propyl cellulose and the like,

- organic, fully synthetic compounds, such as polyacrylic and polymethacrylic compounds, vinyl polymers, polycarboxylic acids, polyethers, polyimines, polyamides,

- inorganic compounds, such as polysilicic acids, clay minerals such as montmorillonites, zeolites, silicas.

According to the present invention it is preferred, if hydrocolloids are contained, which are fully synthetic compounds, in particular polyacrylic and/or polymethacrylic compounds. Polyacrylates may be homopolymers of acrylic acid, which are then referred to as carbomers. An advantageous carbomer may be obtained from Lubrizol Advanced Materials under the trade name Carbopol 980, for example.

It is preferred, if copolymers containing (meth-) acrylic acid and further monomers are contained in the composition of the present invention. It is more preferred, if the further monomers are alkyl acrylates and/or alkyl methacrylates, even more preferred having alkyl radicals with 10 to 30 carbon atoms (C10-C30) . For example, such a polymer is an Acrylates/C10-C30 Alkylacrylate Crosspolymer (INCI name) , which is available from Lubrizol Advanced Materials under the trade name Carbopol ETD 2020.

The copolymers containing (meth-) acrylic acid and further monomers, especially those where the further monomers are chosen from C10-30 alkyl acrylates, contribute to the building of a network structure, particularly in combination with the relatively high amounts of glycerol. In said combination the amount needed of the additional thickening agent can be reduced.

If in the composition of the present invention at least one thickening agent is contained, the at least one thickening agent is contained in a total amount of 0.05 to 1.5%by weight, preferably 0.3 to 0.7%by weight, referring to the total weight of the composition and referring to the active content.

Likewise, advantageously at least one organic acid is contained in the composition of the present invention. It is preferred, if the organic acid is citric acid. If at least one organic acid is contained, the at least one organic acid is contained in a total amount of 0.1 to 2.0%by weight, preferably 0.2 to 1.5 %by weight, referring to the total weight of the composition.

By adding the at least one organic acid a specific pH value is adjusted. The pH values are in the range of 6.20 to 7.00, preferably 6.50 to 6.90.

The addition of the at least one organic acid, particularly citric acid, has an effect on the amino acid surfactants, namely sodium alkyl glycinate and potassium alkyl glycinate. Without being bound to theory, it may be assumed that at pH values around the pK _a half of alkyl glycinate molecules are present in a protonated form and the other half in dissociated form, both of which are interacting through hydrogen bonding. Moreover, the alkyl residues are also interacting thereby establishing a kind of double layer structure. If these structures are assembling a lamellar structure is built up.

If the pH value increases micellar structures may form or if sufficient cations are present, the acidic groups will interact via the cations building up a similar structure as at a pH value around the pK _a value. Hence, flat lamellar structures may form and stabilize the composition and contribute to a suitable consistency. Besides, spherical crystalline structures may also be generated. Aphoto of a composition according to the invention (Example 1) showing lamellar structures (indicated by long arrows) and spherical crystalline structures (indicated by short arrows) is shown in Figure 1. The photo was taken using a polarizing microscope of the company Nikon, type ECLIPSE Ci-POL; the magnification was 550 x.

In the composition of the present invention at least one further surfactant chosen from amphoteric surfactants may be contained.

Amphoteric surfactants may be classified in the following groups:

1. Acyl/dialkyl ethylenediamine, for example sodium acylamphodiacetate, disodium acylamphodipropionate, disodium alkylamphodiacetate, sodium acylamphohydroxypropylsulfonate, disodium acylamphodiacetate and sodium acylamphopropionate,

2. N-alkylamino acids, for example aminopropylalkylglutamide, alkylaminopropionic acid, sodium alkylimidodipropionate and lauroamphocarboxyglycinate.

3. Betaines, for example Coco Betaine, Cocoamidopropyl Betaine,

4. Sultaines, for example lauryl hydroxy sultaine.

According to the present invention it is preferred, if at least one amphoteric surfactant, chosen from the group of betaines, particularly from alkyl amidopropylbetaines, is contained. It is more preferred, if Cocamidopropyl betaine is contained.

If at least one amphoteric surfactant is contained in the composition of the present invention, the at least one amphoteric surfactant is contained in a total amount of 1 to 6%by weight, preferably 3 to 5%by weight, referring to the total weight of the composition and referring to the active content.

Additionally, in the composition of the present invention at least one emollient may be contained. Emollients are known to act on the skin by softening and smoothing the skin. Frequently, emollients are chosen from lipophilic compounds, such as lanolin, mineral oil and petroleum jelly, further fats and waxes.

According to the present invention the emollient is chosen from

- hydrocarbon components having at least 12 carbon atoms,

- esters from alcohols having at least three carbon atoms and 2 or 3 hydroxyl groups, and organic acids having alkyl residues of more than 11 carbon atoms,

- ethers having in total at least 12 carbon atoms and being derived from alcohols having 2 to 22 carbon atoms and at least one hydroxyl group;

- fatty alcohols having alkyl residues of at least 11 carbon atoms,

- mixtures thereof.

It is preferred, if the emollient is chosen from hydrocarbon components having at least 12 carbon atoms, more preferred from polyolefins. It is most preferred, if polyisobutene or hydrogenated polyisobutene is contained.

If at least one emollient is contained, the at least one emollient is contained in a total amount of 0.1 to 2.0%by weight, preferably 0.5 to 1.0%by weight, referring to the total weight of the composition.

Additionally, the composition of the present invention may contain at least one preservative. All preservatives, which are allowed and suitable for cosmetic compositions, may be contained in the composition according to the invention.

However, it is preferred, if Phenoxyethanol is contained in the composition according to the invention. Phenoxyethanol is contained in an amount of 0.5 to 0.9%by weight, preferably 0.8 to 0.9%by weight, referring to the total weight of the composition.

It is likewise preferred, if one or more paraben (s) is/are contained. Parabens are characterized by the following formula

wherein R is a linear or branched alkyl residue of 1 to 5 carbon atoms. Common parabens are methyl-, ethyl-, propyl-, butylparaben, as well as isopropyl-, isobutyl-, pentyl-, and phenylparaben. It is more preferred, if methyl-and/or ethylparaben are contained.

The one or more paraben (s) is/are contained in a total amount of 0.1 to 0.5%by weight, preferably 0.2 to 0.3%by weight, referring to the total weight of the composition.

It is also likewise preferred, if a combination of one or more parabene (s) and Phenoxyethanol is contained.

Additionally, the composition of the present invention may contain at least one pearlescent agent.

Due to pearlescent agents the compositions have an opaque, shimmering sheen. Pearlescent agents are of very different nature and composition. Preference is given to pearlescent agents from the group of ethylene glycol monostearate, ethylene glycol distearate, polyethylene glycol distearate, glycol distearate and/or PEG-3 distearate, preferably from the group of glycol distearate and/or PEG-3 distearate. PEG-3 distearate is available, for example, under the trade name Cutina TS and Glycol Distearate is available, for example, under the trade name Euperlan PK 3000 OK, both times from BASF.

If at least one pearlescent agent is contained in the composition of the present invention, the at least one pearlescent agent is contained in a total amount of 2 to 7%by weight, preferably 4 to 6%by weight, referring to the total weight of the composition.

The composition according to the present invention illustrated by the examples following below may be produced by any technique suitable to prepare this kind of composition. However, it is recommended to prepare the composition according to the present invention by the following method:

- Disperse the acrylic copolymer, e.g. Acrylates/C10-30 Alkyl Acrylate Copolymer in water and heat to 75℃ (phase A) ,

- Disperse Potassium Cocoyl Glycinate in glycerol at room temperature (phase B) , then add phase B to phase A (now phase A + B) and heat to 75℃,

- Add Sodium Cocoyl Glycinate (phase C) and amphoteric surfactant, e.g. Cocamidopropyl Betaine (phase D) separately into phase A + B, homogenize until a uniform mixture is achieved (phase A + B + C+ D) ,

- Add pearlizing agent, e.g. Glycol Distearate (phase E) and emollient, e.g. Polyisobutene (phase F) separately into (phase A + B + C + D) and stir at 75℃ until a uniform mixture is achieved (phase A + B + C + D + E + F = phase X) .

- Add organic acid, e.g. citric acid (phase G) slightly to phase X and stir at 75℃ until a uniform mixture is achieved,

- Cool down to 45℃ and add perfume (phase H) and preservative, e.g. Phenoxyethanol (phase I) ,

- Cool down to 38℃ and discharge into tubes.

Brief description of the Drawings

Fig. 1 shows a polarizing microscopic photo of a composition according to Example 1, wherein the long arrows are pointing to flat lamellar structures, and the short arrows point to crystalline spherical structures.

Examples

The examples are intended to illustrate the present invention without limiting it. The numerical values in the examples are percentages by weight, based on the total weight of the particular preparations. The values are referring to raw material content.

Example 5

Effect Examples

In order to show that the above-mentioned problems were solved an in-use-test was conducted in Shanghai and Guangzhou. The test was monadic and blind. 50 test samples were handed out per product and per city together with a questionnaire. The persons who received the products were female in the age of 18 to 35 years. The skin types of oily &oily combined, neutral, and dry &dry combined were nearly equally distributed. The brands currently used showed that the Dove product was preferred more (40%) and the Nivea and HADA LABO products being equally used, each reaching a 30%value.

Five products were analyzed, three compositions according to the invention (the product Q85 refers to a composition according to Example 3; the product J62 refers to a composition according to Example 2, and the composition of the product M34 refers to Example 5) and two competitor products, namely HADA LABO Gokujun Hyaluronic Face Wash and Dove Nutrium Moisture Cleanser.

According to the INCI listing HADA LABO Gokujun Hyaluronic Face Wash contains Glycerin, Potassium Cocoyl Glycinate, Aqua, Propanediol, Citric Acid, Potassium Chloride, Glycol Distearate, Coconut Acid, Caprylic/capric Glycerides Polyglycerin-10 Esters, potassium coconate, Phytosteryl/octyldodecyl Lauroyl Glutamate, Sodium Acetylated Hyaluronate, Inositol, Sodium PCA, Sodium Lactate, Arginine, Aspartic Acid, PCA, 1, 2-hexanediol, Moringa Pterygosperma Seed Extract, Glycine, Biosaccharide Gum-4, Alanine, Hydroxypropyltrimonium Hyaluronate, Disodium Phosphate, Serine, Valine, Isoleucine, Threonine, Proline, Phenylalanine, Histidine, Chlorphenesin, Phenoxyethanol, Methylparaben.

According to the INCI listing Dove Nutrium Moisture Cleanser contains Aqua, Petrolatum, Potassium Cocoyl Glycinate, Glycerin, Potassium Carbonate, Sodium Lauroamphoacetate, Hydroxypropyl Starch Phosphate, Acrylates Copolymer, Lauric Acid, Lauramidopropyl Betaine, Polybutene, Sodium Cocoyl Isethionate, fragrance, Stearic Acid, Polyquaternium-6, Palmitic Acid, Citric Acid, BHT, Tetrasodium EDTA, Coconut Acid, Sodium Isethionate, Magnesium Nitrate, Methylchloroisothiazolinone, Magnesium Chloride, Methylisothiazolinone.

In the in-use-test several aspects were analyzed. One aspect was the evaluation of a cleansing effect. Referring to the overall cleansing effect all three compositions according to the present were evaluated as good as the competitor products. In relation to the question, if “the face looks clean and bright after cleansing” , the composition Q85 was clearly evaluated best of all five products.

Referring to the foaming properties, the composition M34 is evaluated best, but also the compositions Q85 and J62 are evaluated in a similar way as the competitor products in relation to overall foaming. Referring to foam creaminess the product according to the composition Q85 is evaluated best.

Furthermore, a question referring to the mildness of the product revealed that the composition M34 is evaluated as mild as the competitor product Dove Nutrium Moisture Cleanser, the composition Q85 being nearly as mild as the product according to the composition M34 and the Dove Nutrium Moisture Cleanser. Hence, the products according to the invention are as mild as the competitor products.

.

Claims

A cosmetic cleansing composition containing

- an amino acid surfactant system consisting of sodium alkyl glycinate and potassium alkyl glycinate,

- glycerol in an amount greater than 25 %by weight, referring to the total weight of the composition.
Composition according to claim 1 characterized in that no further amino acid surfactants are contained; preferably no further anionic surfactants are contained.
Composition according to claim 1 and/or claim 2 characterized in that the amino acid surfactant system consisting of sodium alkyl glycinate and potassium alkyl glycinate is contained in an amount of 10 to 30%by weight, preferably 12 to 20%by weight, referring to the total weight of the composition and referring to the active content of each surfactant.
Composition according to any of the preceding claims characterized in that sodium alkyl glycinate is contained in an amount of 1 to 5%by weight, preferably 3 to 4%by weight, referring to the total weight of the composition and referring to the active content.
Composition according to any of the preceding claims characterized in that potassium alkyl glycinate is contained in an amount of 8 to 25%by weight, preferably 10 to 20%by weight, referring to the total weight of the composition and referring to the active content.
Composition according to any of the preceding claims characterized in that the alkyl residue of sodium alkyl glycinate and potassium alkyl glycinate comprises 6 to 22 carbon atoms, preferably sodium cocoyl glycinate and potassium cocoyl glycinate are contained.
Composition according to any of the preceding claims characterized in that sodium alkyl glycinate and potassium alkyl glycinate are contained in a weight ratio in the range of 3: 1 to 1: 10, preferably 2: 1 to 1: 4, and more preferably 1: 1 to 1: 2.3.
Composition according to any of the preceding claims characterized in that water is contained in an amount of 5 to 35%by weight, preferably 10 to 30%by weight, referring to the total weight of the composition.
Composition according to any of the preceding claims characterized in that glycerol is contained in an amount of 25 to 40%by weight, preferably 30 to 39%by weight, referring to the total weight of the composition.
Composition according to any of the preceding claims characterized in that additionally at least one thickening agent is contained, preferably chosen from polyacrylic and/or polymethacrylic compounds and/or copolymers containing (meth-) acrylic acid and further monomers.
Composition according to claim 10 characterized in that the polyacrylic compounds are homopolymers of acrylic acid.
Composition according to claim 10 characterized in that the copolymer containing (meth-) acrylic acid and further monomers is an Acrylates/C10-C30 Alkylacrylate Crosspolymer.
Composition according to claim 10 characterized in that the at least one thickening agent is contained in a total amount of 0.05 to 1.5 %by weight, preferably 0.3 to 0.7%by weight, referring to the total weight of the composition and referring to the active content.
Composition according to any of the preceding claims characterized in that additionally at least one organic acid is contained, preferably citric acid.
Composition according to claim 14 characterized in that the at least one organic acid is contained in a total amount of 0.1 to 2.0%by weight, preferably 0.2 to 1.5 %by weight, referring to the total weight of the composition.
Composition according to any of the preceding claims characterized in that additionally at least one further surfactant chosen from amphoteric surfactants is contained, preferably chosen from the group of betaines, more preferably from alkyl amidopropylbetaines, and most preferably Cocamidopropyl betaine.
Composition according to claim 16 characterized in that the at least one amphoteric surfactant is contained in a total amount of 1 to 6%by weight, preferably 3 to 5%by weight, referring to the total weight of the composition and referring to the active content.
Composition according to any of the preceding claims characterized in that the composition forms and/or contains flat lamellar structures and/or spherical crystalline structures.