WO2023057134A1

WO2023057134A1 - Rinse off anti-pollution emulsion

Info

Publication number: WO2023057134A1
Application number: PCT/EP2022/074083
Authority: WO
Inventors: Anais IBARRA; Ana Karen ZAVALA RAYA; Osvaldo José Fabián CRUZ CERVANTES; Felipe de Jesus Koch Palatto; Thais Leticia ROVIGATTI
Original assignee: Beiersdorf Ag
Priority date: 2021-10-05
Filing date: 2022-08-30
Publication date: 2023-04-13

Abstract

The present invention belongs to the cosmetic field.

Description

Rinse off anti-pollution emulsion

The present invention belongs to the cosmetic field and relates to a specific use of cosmetic ingredients allowing for an effective protection of the human skin from particulate matter by forming by protective layer or conditioning the skin in a way such that particulate matter does less adhere to the skin and can be washed away easily with tap water.

A beautiful and attractive appearance is a desire for many people. One typical sign of such an appearance is a healthy and smooth looking skin. Therefore, in order to take care on the skin, it is for many people a daily routine to apply cosmetic products such as cleansing formulations, in particular body wash or shampoo products.

One purpose of cosmetic products is to protect the human skin from environmental effects. For example, compositions containing UV-filters are commonly used to protect the skin from the ultraviolet radiation of the sunlight. In addition to the acute damage (sunburn), long-term damage such as an increased risk of skin cancer occurs in case of excessive irradiation with light from the UVB range (wavelength: 280-320 nm). The excessive exposure of UVB and UVA radiation (wavelength: 320-400 nm) also leads to a weakening of the elastic and collagen fibers of the connective tissue. This leads to numerous photo-toxic and photo- allergic reactions and results in premature skin ageing.

To protect the skin, a number of light protection filter substances have been developed, which can be used in cosmetic preparations. These UVA and UVB filters are grouped in the most developed countries in the form of positive lists such as Annex VI of the Regulation (EC) No 1223/2009 of the European Parliament and of the Council.

However, besides the sunlight the human skin is also exposed to many other environmental factors. For example, in some global regions it is problematic that due to the environmental pollution the concentration of fine particulate matter in the air is high. The term particulate matter is understood as solid matter suspended in the earth’s atmosphere. Sources of particulate matter can be natural or anthropogenic.

A special kind of particulate matter are particles from smog, tobacco smoke and flying ash, which appearance may be caused by forest fires, smoking or the exhaust of engines. Such particulate matter usually has a diameter in the range from 0.01 m to 100 pm, wherein smog and tobacco smoke typically cover the range from 0.01 pm to 2.5pm.

It is generally known that particulate matter, especially from smog and tobacco smoke, may adversely affect the human health. Inhalation of such particles may lead to an increased risk of lung cancer. However, high concentration of such particulate matter in the air also leads to an increased particle deposition on the skin. The correlation between high concentration of particulate matter in the air and the effect on the skin has recently been evaluated in a number of scientific studies.

For example, the disclosure “Premature skin aging by infrared radiation, tobacco smoke and ozone" by P. Schroder, S.M. Schieke and A. Morita (Skin Aging; Springer-Verlag; pp 45-55) discusses the effect of faster aging skin caused by tobacco smoke. Furthermore, a study by A. Vierkbtter, T. Schikowski, II. Ranft, D. Sugiri, M. Matsui, II. Kramer and J. Krutmann (Airborn Particle Exposure and Extrinsic Skin Aging, Journal of Investigative Dermatology 2010; 130; pp 2719-2726) indicated that the particle emission of engines may also correlate to a faster skin aging.

Cosmetic products are often used to protect the human skin from environmental effects. For example, the US2007/0003536 discloses a method for protecting human skin against oxidizing species and oxidative damages of the skin. Although the document is addressed to environmental effects, it does not address the easy and effective removal of particulate matter after deposition from the air.

Furthermore, the US2002/0192178 discloses a method for protecting the skin against the effects of pollution, comprising the application of a composition which contains an aqueous extract of maize. The extract of the invention is used as a heavy metal-scavening agent. However, the document does not address the easy and effective removal of particulate matter after deposition from the air.

Another example is the US patent application 2009/0035235, which describes a cosmetic composition that is capable of combating and preventing the effects of atmospheric pollution on the skin containing two vegetable extracts: Camellia sinensis (white tea) and Lapsana communis. The composition containing these two extracts exhibits an antiradical activity, provides protection against lipoperoxidation caused by exhaust gases and stimulates the mitochondrial respiration. Again, there is no disclosure in regard to an effective removal of particulate matter. Looking at the state of the art, it can be noticed that there are a number of documents addressing pollution effects. However, it is pointed out that none of the cited documents addresses compositions which can be applied to the skin before the exposure to the particulate matter and which allow an easy and effective removal of the deposited material with water after exposure.

Further, it can be noticed that cleansing formulations to be used as body wash are conventionally be used to remove particulate matter from the skin in the following manner:

1. Applying water to skin which has absorbed particulate matter

2. Applying the cleansing formulation to the wet skin

3. Washing off the cleansing formulation and the particulate matter with water.

In this way the skin is sufficiently cleansed. However, in the case that new particulate matter is deposited on the skin, the steps 1. to 3. have to be repeated to cleanse the skin again. Thus, the same amount of cleansing formulation is released due to step 3 in the sewage system a second time. However, in environmental terms it is of general interest to reduce the amount of cleansing formulations which is released in the sewage system.

Thus, it is desirable to provide ways to reduce the amount of cleansing formulation and allow a repetitive washing of the skin.

It is desirable to provide a cleansing formulation which allows to wash the skin a first time and a second time with water, whereby there is no need to apply the formulation a second time to allow for an effective removal of particulate matter, which is deposited on the skin after the first wash.

It was surprisingly found by the application that the objectives can be met by the present invention.

A first object of the present invention is the use of a cosmetic cleansing emulsion comprising based on the total weight of the emulsion a. at least one anionic surfactant, b. at least one amphoteric surfactant, c. from 2 to 12% by weight of at least one oil d. from 2 to 10% by weight of at least one fatty acid, and e. from 0.1 to 3.5% by weight of at least one non-ionic polysaccharide. to a) condition the human skin such that particulate matter, which is deposited onto the skin after application of the emulsion, can be rinsed off the skin with water, and/or b) to form a protective layer or protective barrier on the human skin, whereby the protective layer or barrier allows particulate matter, which is deposited onto the skin after application of the emulsion, to be rinsed off the skin with water, and/or c) to protect the human skin from pollution, in particular from particulate matter, which is deposited onto the skin after application of the emulsion on the human skin, whereby the emulsion allows the deposited particulate matter to be rinsed off the skin with water.

Application as used herein means washing of the skin.

It was surprisingly noticed that after washing the human skin with the emulsion particulate matter, which is deposited after washing, may be removed easily by rinsing the skin with tap water. Accordingly, the objectives of the present invention are solved.

All the weight percentages (% by weight) given below relate, unless otherwise stated, to the total weight of the cosmetic emulsion. If ratios of certain components are disclosed in the following description, these ratios refer, unless otherwise stated, to weight ratios of the components.

Unless otherwise stated, all tests and measurements were performed under “normal conditions”. The term "normal conditions" refers to 20°C, 1013 hPa and a relative humidity of 50%.

In the following description the terms ..according to the invention”, “preferred according to the invention” and so on are always directed to the use according to the invention, to the emulsion and to the method according to the invention.

For the purposes of the present disclosure, the term "free from" means that the proportion of the respective substance is less than 0.05% by weight. This ensures that entrainments or impurities with these substances are not included as "free from" according to the invention.

The term “skin” refers solely to the human skin. Emulsifiers are understood to be all substances which are listed in the International Cosmetic Ingredient Dictionary and Handbook, Thirteenth Edition 2010, (ISBN 1-882621-47-6) under the name "emulsifying agent". Surfactants are understood to be all substances which are listed in the International Cosmetic Ingredient Dictionary and Handbook, Thirteenth Edition 2010, (ISBN 1-882621-47-6) under the name "surfactant".

The emulsion of the invention is preferably a body wash.

The emulsions according to the invention include as a first essential ingredient at least one anionic surfactant, preferably being used in only relatively small amounts. It is preferred that the percentage by weight of the anionic surfactant relative to the total weight of the emulsion is 4.0 to 15.0% by weight, preferably 5.0 to 11.0% and most preferably 6.0 to 8.0% by weight.

Preferred anionic surfactants according to the invention include: linear and branched fatty acids having 8 to 30 C atoms (soaps), ether carboxylic acids of the formula R — O — (CH2 — CH2O)_X — CH2 — COOH, in which R is a linear or branched, saturated or unsaturated alkyl group having 8 to 30 C atoms and x=0 or 1 to 16, acyl sarcosides having 8 to 24 C atoms in the acyl group, acyl taurides having 8 to 24 C atoms in the acyl group, acyl isethionates having 8 to 24 C atoms in the acyl group, sulfosuccinic acid mono- and/or dialkyl esters having 8 to 24 C atoms in the alkyl group and sulfosuccinic acid monoalkylpolyoxyethyl esters having 8 to 24 C atoms in the alkyl group and 1 to 6 oxyethyl groups, alpha-olefinsulfonates having 8 to 24 C atoms, alkyl sulfate and/or alkyl polyglycol ether sulfate salts of the formula R — (OCH2 — CH2)X — OSO3 "M⁺, in which R is a preferably linear or branched, saturated or unsaturated alkyl group having 8 to 30 C atoms, x=0 or 1 to 12, and M is an alkali or ammonium ion, sulfonates of unsaturated fatty acids having 8 to 24 C atoms and 1 to 6 double bonds, esters of tartaric acid and citric acid with alcohols, which are adducts of about 2-15 molecules of ethylene oxide and/or propylene oxide to fatty alcohols having 8 to 22 C atoms, alkyl and/or alkenyl ether phosphates of the formula,

in which R¹ preferably stands for an aliphatic hydrocarbon group having 8 to 30 carbon atoms, R² for hydrogen, a group (CH2CH2O)_nR¹ or X, n for numbers from 0 to 10, and X for hydrogen, an alkali metal or alkaline earth metal, or NR³R⁴R⁵R⁶, where R³ to R⁶ independently of one another stand for a Ci to C4 hydrocarbon group.

Preferred anionic surfactants are ether carboxylic acids of the aforementioned formula, acyl sarcosides having 8 to 24C atoms in the acyl group, sulfosuccinic acid mono and/or -dialkyl esters having 8 to 24 C atoms in the alkyl group and sulfosuccinic acid monoalkyl polyoxyethyl esters having 8 to 24C atoms in the alkyl group and 1 to 6 oxyethyl groups, alpha-olefinsulfonates having 8 to 24C atoms, and/or alkylsulfate salts and/or alkyl polyglycol ether sulfate salts of the aforementioned formula.

Especially preferred anionic surfactants are straight-chain or branched alkyl ether sulfates, which include an alkyl group having 8 to 18 and especially having 10 to 16 C atoms, and 1 to 6 and particularly 2 to 4 ethylene oxide units. Furthermore, especially preferred anionic surfactants are straight-chain or branched alkyl sulfonates, which include an alkyl group having 8 to 18 and especially having 10 to 16 C atoms. Preferred in particular are the sodium, magnesium, and/or triethanolamine salts of linear or branched lauryl, tridecyl, and/or myristyl sulfates, which have a degree of ethoxylation of 2 to 4.

Very especially preferred emulsions according to the invention are characterized in that they include at least one anionic surfactant from the group of alkyl sulfates and alkyl polyglycol ether sulfates of the formula R — (OCH2 — CFhX — OSO3M, in which R preferably stands for a straight-chain or branched, saturated or mono- or polyunsaturated alkyl or alkenyl group having 8 to 24 carbon atoms, x for 0 or 1 to 12, and M for an alkali metal or alkaline earth metal or for triethanolamine, whereby anionic surfactants with the inci name sodium lauryl sulfate and sodium laureth sulfate are especially preferred.

The emulsions according to the invention include at least one amphoteric surfactant as a second essential ingredient. Amphoteric surfactants are added to the agents according to the invention, based on their total weight, preferably in amounts from 1 .0 to 12% by weight, more preferably from 2.0 to 10% by weight, and especially from 2.5 to 6.0% by weight. Preferred amphoteric surfactants can be selected from compounds of the following formulas (i) to (v), in which the group R in each case stands for a straight-chain or branched, saturated or mono- or polyunsaturated alkyl or alkenyl group having 8 to 24 carbon atoms,

Especially suitable amphoteric surfactants are alkyl amidoalkyl betaines and/or alkyl ampho(di)acetates of the aforementioned formulas (I) to (V). Especially suitable amphoteric surfactants include the surfactants known under the INCI names cocam idopropyl betaine and disodium cocoamphodiacetate. Emulsions especially preferred according to the invention are characterized in that they include at least one amphoteric surfactant from the group of the general formula (III), whereby amphoteric surfactants with the INCI name cocamidopropyl betaine are especially preferred.

Preferred emulsions according to the invention are characterized in that the percentage by weight of the anionic surfactant and amphoteric surfactant in the emulsion, based on the total weight of the emulsion, is 6.0 to 15% by weight, preferably 8.0 to 11% by weight.

According to the invention the emulsion comprises at least one oil in a total quantity ranging from 2 to 12% by weight, more preferably 4 to 10% by weight and most preferably 4.5 to 7% by weight, calculated to the total weight of the emulsion.

Suitable oils are can be preferably selected from mineral, natural, and synthetic oil components. However, natural and/or synthetic oils are more preferred than mineral oils.

Triglycerides and mixtures of triglycerides are usually employed as natural (plant) oils. Preferred natural oils are coconut oil, (sweet) almond oil, walnut oil, peach kernel oil, apricot kernel oil, avocado oil, tea tree oil, soybean oil, glycine soja oil, sesame oil, sunflower oil, tsubaki oil, evening primrose oil, rice bran oil, palm kernel oil, mango kernel oil, cuckoo flower oil, thistle oil, macadamia nut oil, grape seed oil, amaranth seed oil, argan oil, bamboo oil, olive oil, wheat germ oil, pumpkin seed oil, mallow oil, hazelnut oil, safflower oil, canola oil, sasanqua oil, jojoba oil, rambutan oil, cocoa butter, and shea butter. Glycine soja oil is preferred.

Mineral oils, paraffin oils, and isoparaffin oils, and synthetic hydrocarbons in particular are used as mineral oils.

A dialkyl ether can serve furthermore as an oil. Dialkyl ethers which can be used are, in particular, di-n-alkyl ethers having a total of between 12 and 36 carbon atoms, particularly 12 to 24 carbon atoms, such as, for example, di-n-octyl ether, di-n-decyl ether, di-n-nonyl ether, di-n-undecyl ether, di-n-dodecyl ether, n-hexyl n-octyl ether, n-octyl n-decyl ether, n-decyl n- undecyl ether, n-undecyl n-dodecyl ether, and n-hexyl n-undecyl ether, as well as di-tert-butyl ether, di-isopentyl ether, di-3-ethyldecyl ether, tert-butyl n-octyl ether, isopentyl n-octyl ether, and 2-methylpentyl n-octyl ether.

Further oils preferred according to the invention are ester oils. Ester oils are understood to be the esters of C6-C30 fatty acids with C2-C30 fatty alcohols. The monoesters of the fatty acids with alcohols having 2 to 24 C atoms are preferred. Examples of employed fatty acid components in the esters are caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, lauric acid, isotridecanoic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, elaeostearic acid, arachidic acid, gadoleic acid, behenic acid, and erucic acid, and technical mixtures thereof. Examples of the fatty alcohol components in the ester oils are isopropyl alcohol, caproic alcohol, caprylic alcohol, 2-ethylhexyl alcohol, capric alcohol, lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, linolyl alcohol, linolenyl alcohol, elaeostearyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, and brassidyl alcohol, and technical mixtures thereof. Isopropyl myristate (Rilanit® I PM), isononanoic acid C16-18 alkyl ester (Cetiol® SN), 2-ethylhexyl palmitate (Cegesoft® 24), stearic acid 2-ethylhexyl ester (Cetiol® 868), cetyl oleate, glycerol tricaprylate, coconut fatty alcohol caprinate/caprylate (Cetiol® LC), n-butyl stearate, oleyl erucate (Cetiol® J 600), isopropyl palmitate (Rilanit® IPP), oleyl oleate (Cetiol®), lauric acid hexyl ester (Cetiol® A), di-n-butyl adipate (Cetiol® B), myristyl myristate (Cetiol® MM), cetearyl isononanoate (Cetiol® SN), and oleic acid decyl ester (Cetiol® V) are especially preferred.

Further, it is preferred if the oil contained in the emulsion is a PPG-alkyl ether. Preferred

PPG-alkyl ethers are selected from the group defined by the formula

wherein / is an integer in the range from 4 to 20, and j is an integer in the range from 2 to 20.

Preferred PPG-alkyl ethers are defined by / being an integer in the range from 10 to 18 and j being an integer in the range from 10 to 16. More preferred is the PPG- 15 stearyl ether.

Most preferred is the use of PPG-alkyl ethers as defined above and/or natural oils as described above. Accordingly it is exceptional preferred if the emulsion comprises at least one PPG-alkyl ether according to the formula above, wherein / is an integer in the range from 4 to 8 and j is an integer in the range from 2 to 15, and/or a natural oil in a total quantity ranging from 2 to 12% by weight, more preferably 4 to 10% by weight and most preferably 4.5 to 7% by weight, calculated to the total weight of the emulsion.

Preferred embodiments of the invention are characterized in that PPG-15 stearyl ether and/or a natural oil are contained in the emulsion in a total quantity ranging from 2 to 12% by weight, more preferably 4 to 10% by weight and most preferably 4.5 to 7% by weight, calculated to the total weight of the emulsion.

A further preferred oil is cocoglycerides. Cocoglycerides is preferably contained in the emulsion in a total quantity ranging from 2 to 12% by weight, more preferably 4 to 10% by weight and most preferably 4.5 to 7% by weight, calculated to the total weight of the emulsion.

In another embodiment of the invention it is preferred if the oil contained has an interfacial tension towards water of less than 25 mN/m, more preferably less than 20 mN/m, more preferably less than 15 mN/m and most preferably less than 10 mN/m.

The interfacial tension is the force which acts on an imaginary line one meter in length at the interface between two phases. The physical unit for this interfacial tension is conventionally calculated from the force/length relationship and is usually expressed in mN/m (millinewtons divided by meters). It has a positive sign if it tends to reduce the interface. In the converse case, it has a negative sign. Generally, oils are regarded as polar if their interfacial tension towards water is less than about 20 mN/m, and as nonpolar if their interfacial tension towards water is more than about 30 mN/m. Oils with an interfacial tension towards water between about 20 and about 30 mN/m are generally referred to as moderately polar.

The following table indicates the interfacial tension towards water of a number of oils:

It was further surprisingly noticed that the presence of the fatty acid further aids the removal of particulate matter with water, whereby the particulate matter is deposited after cleansing with the emulsion. Thus, it helps to build a protective barrier allowing a fast and easy removal of deposited particulate matter with water.

Last but not least, the emulsion of the invention comprises from 0.1 to 3.5% by weight of at least one non-ionic polysaccharide, calculated to the total weight of the emulsion. It is preferred if the total quantity of the non-ionic polysaccharide is in the range from 0.2 to 1.2% by weight, more preferably 0.3 to 1.0% by weight, more preferably 0.4 to 0.8% and most preferably 0.4 to 0.7% by weight, calculated to the total weight of the emulsion.

According to the invention it is preferred if the nonionic Polysaccharide is selected from natural gums. Natural gums are for example sclerotium gum and xanthan gum. It is particularly preferred if xanthan gum is included as nonionic polysaccharide.

Accordingly, it is preferred if a natural gum is included in the range from 0.2 to 3.5% by weight, more preferably 0.3 to 1.0% by weight, more preferably 0.4 to 0.8% and most preferably 0.4 to 0.7% by weight, calculated to the total weight of the emulsion.

Accordingly, it is particularly preferred if xanthan gum is included in the range from 0.2 to 3.5% by weight, more preferably 0.3 to 1.0% by weight, more preferably 0.4 to 0.8% and most preferably 0.4 to 0.7% by weight, calculated to the total weight of the emulsion.

Further, it is preferred if the emulsion comprises at least one emulsifier. Thereby, it is preferred if the ratio of the total quantity of the emulsifier to the total quantity of the oil phase is in the range from 1 :1 to 1 :20, more preferably 1 : 1.1to 1 :5, more preferably 1 :1.2 to 1 :2 and most preferably 1 :1.3 to 1 :1.8. It is noted that by definition emulsifier and surfactants are not calculated to the total quantity of the oil phase.

In one embodiment of the invention preferred emulsifier are nonionic emulsifier. Although, basically all nonionic emulsifier can be contained in the emulsion of the invention, some emulsifiers were found to be particularly beneficial for the effect described. Preferred nonionic emulsifier are selected from oleth-20, glyceryl stearate, glyceryl stearate SE and PEG-40 hydrogenated castor oil.

It is particularly preferred are glyceryl stearate and/or glyceryl stearate SE.

According to the invention it is preferred if the ratio of the total quantity of the nonionic emulsifier to the total quantity of the oil phase is in the range from 1:1 to 1 :20, more preferably 1:1.1 to 1:5, more preferably 1:1.2 to 1:2 and most preferably 1 :1.3 to 1 :1.8.

In particular it is preferred if the total quantity of the nonionic emulsifier selected from oleth- 20, glyceryl stearate, glyceryl stearate SE and PEG-40 hydrogenated castor oil to the total quantity of the oil phase is in the range from 1:1 to 1:20, more preferably 1 :1.1 to 1:5, more preferably 1 : 1.2 to 1 :2 and most preferably 1 : 1.3 to 1:1.8.

In some embodiments it is preferred if the emulsion comprises at least one nonionic emulsifier having an HLB value in the range from 3 to 6. In the case at least one nonionic emulsifier having an HLB value in the range from 3 to 6 is contained, it is preferred if the total quantity of this emulsifier is in the range 2 to 5% by weight. Particularly preferred are glyceryl stearate and/or glyceryl stearate SE.

In another embodiment of the invention it is preferred, if the emulsifier are anionic emulsifier, advantageously selected from the group of anionic emulsifier having a hlb value ranging from 8 to 18, in particular from 10 to 15.

According to the invention it is preferred if the ratio of the total quantity of the anionic emulsifier selected from the group of anionic emulsifier having a hlb value ranging from 8 to 18, in particular 10 to 15, to the total quantity of the oil phase is in the range from 1:1 to 1:20, more preferably 1:1.1 to 1:5, more preferably 1:1.2 to 1 :2 and most preferably 1:1.3 to 1 :1.8.

Preferred are anionic emulsifier selected from glyceryl stearate citrate and glyceryl citrate.

Accordingly it is also preferred in some embodiments that glyceryl stearate citrate and/or glyceryl citrate are contained and the ratio of the total quantity of glyceryl stearate citrate and/or glyceryl citrate to the total quantity of the oil phase is in the range from 1 : 1 to 1 :20, more preferably 1:1.1 to 1:5, more preferably 1 :1.2 to 1 :2 and most preferably 1 :1.3 to 1:1.8. In still another embodiment it is preferred if the comprises anionic and/or nonionic emulsifier, whereby glyceryl stearate citrate, glyceryl citrate, oleth-20, glyceryl stearate, glyceryl stearate SE and/or PEG-40 hydrogenated castor oil are preferred. In that case it is further preferred if the ratio of the total quantity of glyceryl stearate citrate, glyceryl citrate, oleth-20, glyceryl stearate, glyceryl stearate SE and/or PEG-40 hydrogenated castor oil to the total quantity of the oil phase is in the range from 1:1 to 1 :20, more preferably 1 : 1.1to 1 :5, more preferably 1 :1.2 to 1:2 and most preferably 1 :1.3 to 1:1.8.

For the case that glyceryl stearate SE is contained, it is preferred if the total quantity of glyceryl stearate SE is in the range from 0.1 to 3% by weight, more preferably 0.8 to 2.8% by weight and most preferably from 1.5 to 2.5% by weight, calculated to the total weight of the emulsion.

For the case that glyceryl stearate is contained, it is preferred if the total quantity of glyceryl stearate is in the range from 0.1 to 3% by weight, more preferably 0.5 to 2.0% by weight and most preferably from 0.7 to 1.5% by weight, calculated to the total weight of the emulsion.

It should be noted that fatty acids containing 8 to 26 carbon atoms are not considered as emulsifier.

Further, it was noted that it is beneficial according to the invention if the emulsion further comprises at least one fatty alcohol. Fatty alcohols are straight-chain primary alcohols containing 8 to 26 carbon atoms. For the case that at least one fatty alcohol is contained, it is preferred if the total quantity of the fatty alcohols is in the range from 0.5 to 4.0% by weight, more preferably 1.0 to 3% by weight and most preferably 1.5 to 2.5% by weight, calculated to the total weight of the emulsion.

It is preferred if the emulsion is an oil in water emulsion. If the two liquids of an emulsion are water and oil and if oil droplets are finely distributed in water, then this is an oil in water emulsion (O/W emulsion, e.g., milk). The basic character of an O/W emulsion is determined by the water. In the case of a water-in-oil emulsion (W/O emulsion, e.g., butter), the principle is reversed, the basic character here being determined by the oil.

Further it is preferred if the emulsion is free from polymers polymerized from a mixture comprising acrylic acid and/or methacrylic acid. Such polymers were often used in the past. However, due to not known biodegradability these polymers should not be included in state- of-the-art formulations anymore. Accordingly, it is preferred if no polymers polymerized from a mixture comprising acrylic acid and/or methacrylic acid are contained.

Furthermore, it is advantageous if the cosmetic emulsion according to the invention contains water as cosmetic carrier in a proportion of 50% by weight to 90% by weight, preferably 60% by weight to 80% by weight and most preferably from 65% by weight to 78% by weight, based on the total weight of the emulsion.

Further it is preferred if the emulsion comprises sodium benzoate and/or sodium salicylate to ensure antimicrobial stability. For that purpose, it is preferred to have sodium benzoate and/or sodium salicylate contained in a total quantity ranging from 0.1 to 2% by weight, calculated to the total weight of the emulsion.

According to the invention the cosmetic emulison may preferably contain at least one compound selected from the group of limonene, linalool, citral, alpha-isomethylionone and geraniol.

According to the invention it is further preferred if the cosmetic emulsion has a pH value in the range from 4.5 to 8. The pH may be adjusted using citric acid or sodium hydroxide.

Examples:

The following examples should illustrate the compositions of this invention, without intending to limit the invention to these examples. The numerical values in the examples are percentages by weight, based on the total weight of the preparations.

The following methodology was applied to analyze the effective removal of particulate matter after cleansing the skin with a composition followed by the exposure of the skin to particulate matter.

A group of participants has been selected for the study. The forearms of the participants were prepared by cleaning them with water, soap and ethanol. Afterwards several sections having a diameter of 2.5 cm were marked on the forearm. Then the forearm is wet with tap water to apply in each section 10 pl of one of the emulsions. The emulsion is spread in the marked area with 10 circular movements and then rinsed-off with tap water. After rinsing the forearm, the excess of water is removed using a paper towel and the area is left 30 min to fully dry. 30 minutes after application an excessive amount of charcoal powder (vegetable charcoal, 90% below 9.4 pm diameter, 10% below 2.5 pm diameter) was sprinkled over the marked sections ensuring that all sections were fully covered. The excessive amount of charcoal was then removed by flipping the arm 10 times until no further charcoal fell off.

To analyze the effectiveness of the removal of charcoal the marked sections were washed by pouring water onto the sections for 10 seconds. Afterwards, the amount of removed charcoal was optically evaluated by an expert panel using a scale ranging from 0 to 100. A value of 100 stands for a full removal of the charcoal. A value of 0 is chosen if the level of charcoal remaining on the skin is equal or worse compared to a skin section on which no emulsion was applied, but which was treated with charcoal as described above.

The experimental results are indicated in the following table containing example formulations. All formulations designated with Com. X are reference example not according to the invention, whereby X is an integer. All formulations designated with Inv. Y are examples according to the invention, whereby Y is an integer.

The test performed allowed a superior removal score for the inventive examples, as shown in the table.

Claims

1. Use of a cosmetic cleansing emulsion comprising based on the total weight of the emulsion a. at least one anionic surfactant, b. at least one amphoteric surfactant, c. from 2 to 12% by weight of at least one oil d. from 2 to 10% by weight of at least one fatty acid, and e. from 0.1 to 3.5% by weight of at least one non-ionic polysaccharide, to a) condition the human skin such that particulate matter, which is deposited onto the skin after application of the emulsion, can be rinsed off the skin with water; b) to form a protective layer or protective barrier on the human skin, whereby the protective layer or barrier allows particulate matter, which is deposited onto the skin after application of the emulsion, to be rinsed off the skin with water; and/or c) to protect the human skin from pollution, in particular from particulate matter, which is deposited onto the skin after application of the emulsion on the human skin, whereby the emulsion allows the deposited particulate matter to be rinsed off the skin with water.

2. Use according claim 1 characterized in that the percentage by weight of the anionic surfactant relative to the total weight of the emulsion is 6.0 to 15.0% by weight, preferably 8.0 to 11 .0% by weight.

3. Use according to any of the proceeding claims characterized in that the emulsion comprises at least one anionic surfactant from the group of alkyl sulfates and alkyl polyglycol ether sulfates of the formula R — (OCH2 — CH2)x — OSO3M, in which R preferably stands for a straight-chain or branched, saturated or mono- or polyunsaturated alkyl or alkenyl group having 8 to 24 carbon atoms, x for 0 or 1 to 12, and M for an alkali metal or alkaline earth metal or for triethanolamine.

4. Use according to any of the proceeding claims characterized in that amphoteric surfactants are contained in amounts from 1.0 to 12% by weight, more preferably from 2.0 to 10% by weight, and especially from 3.0 to 6.0% by weight, based on the total weight of the emulsion. Use according to any of the proceeding claims characterized in that cocamidopropyl betaine is contained as amphoteric surfactant. Use according to any of the proceeding claims characterized in that the emulsion comprises at least one oil in a total quantity ranging from 4 to 10% by weight and preferably 4.5 to 7% by weight, calculated to the total weight of the emulsion. Use according to any of the proceeding claims characterized in that natural and/or synthetic oils are contained. Use according to any of the proceeding claims characterized in that at least one oil selected from the group coconut oil, (sweet) almond oil, walnut oil, peach kernel oil, apricot kernel oil, avocado oil, tea tree oil, soybean oil, glycine soja oil, sesame oil, sunflower oil, tsubaki oil, evening primrose oil, rice bran oil, palm kernel oil, mango kernel oil, cuckoo flower oil, thistle oil, macadamia nut oil, grape seed oil, amaranth seed oil, argan oil, bamboo oil, olive oil, wheat germ oil, pumpkin seed oil, mallow oil, hazelnut oil, safflower oil, canola oil, sasanqua oil, jojoba oil, rambutan oil, cocoa butter, and shea butter is contained. Use according to any of the proceeding claims characterized in that at least one PPG- alkyl ethers are selected from the group defined by the formula

wherein / is an integer in the range from 1 to 12, and j is an integer in the range from 2 to 40 is contained as oil, whereby it is preferred if / is an integer in the range from 4 to 8 and j is an integer in the range from 2 to 15. Use according to any proceeding claim characterized in that the oil contained has an interfacial tension towards water of less than 25 mN/m, more preferably less than 20 mN/m, more preferably less than 15 mN/m and most preferably less than 10 mN/m. Use according to any of the proceeding claims characterized in that the total quantity of the non-ionic polysaccharide is in the range from 0.2 to 1.2% by weight, more preferably 0.3 to 1.0% by weight, more preferably 0.4 to 0.8% and most preferably 0.4 to 0.7% by weight, calculated to the total weight of the emulsion. Use according to any of the proceeding claims characterized in that the nonionic Polysaccharide is selected from natural gums. Use according to any of the proceeding claims characterized in that xanthan gum is included as nonionic polysaccharide. Use according to any of the proceeding claims characterized in that the emulsion comprises at least one nonionic emulsifier having an HLB value in the range from 3 to 6, whereby glyceryl stearate and/or glyceryl stearate SE are preferred. Use according to claim 13 characterized in that the total quantity of the nonionic emulsifier having an HLB value in the range from 3 to 6 is in the range 2 to 5% by weight.