WO2021254588A1

WO2021254588A1 - Solid cleansing composition

Info

Publication number: WO2021254588A1
Application number: PCT/EP2020/066424
Authority: WO
Inventors: Osvaldo José Fabián CRUZ CERVANTES; Manuel Alejandro GARCÍA
Original assignee: Beiersdorf Ag
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2021-12-23

Abstract

The present invention belongs to the cosmetic field and relates to a cosmetic cleansing composition.

Description

Solid cleansing composition

The present invention belongs to the cosmetic field and relates to a cosmetic cleansing bar based on an oil-in-water emulsion.

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 and moisturizing products.

Cosmetic cleansing compositions to be used as body cleanser are mostly provided as gel composition such that the composition can easily be spread over the body before being rinsed off. Besides liquid compositions soap bars were used in the past. Examples of such soap bars are disclosed in DE 10035211 A1. The advantage of a soap bar is that no extra water is contained in the composition such that the total wash active content delivered is significantly higher calculated to the total weight of the product compared the a gel composition. Accordingly, less CO2 is produced while transporting the product, if the content of the wash active material is considered. However, a common disadvantage of soap bars is that due to the high content of fatty acid salts these bars may cause a dry skin feeling when being used frequently.

One cosmetic technology which allows for an effective moisturization of the skin are oil-in- water emulsions which are normally applied in liquid form. If surfactants are included the oil- in-water emulsion may also be used for cleansing purposes.

Solid emulsion based sticks are often used in other cosmetic fields such as for deodorant or antiperspirant which are applied under the armpit to avoid the typical sweat odor. Typical examples of such emulsion based sticks may be found in EP1773454 A2. Other solid emulsion based sticks are used for moisturizing properties. Typical examples of such emulsion based stick may be found in WO 2016/155867 A1.

Although sticks formed by an emulsion base and emulsions containing surfactants are already known in the prior art (see discussion above), it still remains challenging to provide solid emulsion based cleansing composition. In particular it is challenging to provide an emulsion which forms under normal conditions a solid stick with good cleansing properties. That means that the stick allows for an effective cleansing of the skin by releasing the surfactants upon water and body contact. However, the main challenge is that the emulsion forms a solid stick which can be used in the cleansing process. Accordingly the stick must not be too soft, as otherwise it cannot be hold in the hand while washing.

It was now surprisingly discovered by the applicant that certain surfactants allow the emulsion to be become harder upon solidification at room temperature. Accordingly, those surfactants allow for two benefits simultaneously: a) Good cleansing properties for the solidified emulsion and b) Increasing hardness of the solidified emulsion, such that the cleansing bar is less likely to break or does not feel too soft upon use.

A first aspect of the present invention is a cosmetic oil-in-water emulsion comprising a) Sodium cocoyl isethionate.and b) Sodium laureth sulfate and/or sodium stearoyl glutamate.

A further aspect is the use of a) Sodium cocoyl isethionate and b) sodium laureth sulfate and/or sodium stearoyl glutamate; in a cosmetic oil-in-water emulsion to increase the hardness of the a solidified emulsion under normal conditions.

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%.

All temperatures disclosed refer, unless otherwise stated, to a pressure of 1013 hPa.

If percentages by weight (% by weight) are given below without reference to a particular composition or specific mixture, these figures always refer to the total weight of the cosmetic emulsion.

If ratios of certain components are disclosed without reference in the following description, these ratios always refer to weight ratios of the components. If ranges for the weight of certain ingredients are disclosed, the disclosure includes not only the start and end values for the indicated ranges but also the individual values within the ranges in steps of 0.01% by weight.

The phrases "according to the invention", "advantageous according to the invention", "advantageous in the sense of the present invention", etc., refer in the context of the present disclosure always to the composition according to the invention, the use according to the invention and the method according to the invention.

According to the invention it is advantageous if the total quantity of sodium cocoyl isethionate is in the range from 2 to 12%, more preferably from 4 to 10% by weight and most preferably from 6 to 9 % by weight, calculated to the total weight of the emulsion.

It is preferred if sodium laureth sulfate is contained.

According to the invention it is advantageous if the total quantity of sodium laureth sulfate and/or sodium stearoyl glutamate is in the range from 1 to 10% by weight, more preferably 3 to 8% by weight and most preferably from 4.5 to 6 % by weight, calculated to the total weight of the emulsion.

Additionally, it is preferred if the ratio by weight between sodium cocoyl isethionate and the total quantity of sodium laureth sulfate and/or sodium stearoyl glutamate is in the range from 1:1 to 2: 1 , more preferably from 1.25: 1 to 1.9: 1 and most preferably from 1.45: 1 to 1.75: 1.

Further preferred oil-in-water emulsions according to the present invention are characterized in that at least one nonionic emulsifier having an HLB value in the range from 3 to 6 is contained.

Nonionic emulsifiers having an HLB value in the range from 3 to 6 that are preferred according to the present invention are selected from linear saturated and unsaturated C12 to C30 alkanols that are etherified with 1 to 4 ethylene oxide units per molecule.

Particularly preferred nonionic emulsifiers having an HLB value in the range from 3 to 6 are selected from Steareth, Ceteth, Myristeth, Laureth, Trideceth, Arachideth, and Beheneth, having respectively 1 to 4 ethylene oxide units per molecule. Steareth- 1, Steareth-2, Steareth-3, Ceteth- 1, Ceteth-2, Ceteth-3, Myristeth- 1, Myristeth-2, Laureth-1, Beheneth-2, Beheneth-3, and Beheneth-4 are extraordinarily preferred, in particular Steareth-2. Further oil-in-water emulsions that are preferred according to the present invention are characterized in that at least one nonionic emulsifier having an HLB value in the range from 3 to 6 is contained in a total quantity from 0.8 to 3% by weight, preferably 1 to 2.6% by weight, and particularly preferably 1.2 to 2.2% by weight, based in each case on the weight of the entire emulsion.

Further oil-in-water emulsions preferred according to the present invention are characterized in that at least one nonionic emulsifier having an HLB value in the range from 12 to 18 is contained. Nonionic emulsifiers having an HLB value in the range from 12 to 18 that are preferred according to the present invention are selected from linear saturated and unsaturated C12 to C24 alkanols that are etherified with 7 to 40 ethylene oxide units per molecule. Particularly preferred nonionic emulsifiers having an HLB value in the range from 12 to 18 are selected from Steareth, Ceteth, Myristeth, Laureth, Trideceth, Oleth, Arachideth, and Beheneth, having respectively 7 to 40 ethylene oxide units per molecule, in particular Steareth-15, Steareth-20, Steareth-21, Arachideth-20, Arachideth-21, Beheneth-20, Beheneth-21, Ceteth-20, Oleth-20, Ceteth-30, Ceteth- 15, and Myristeth- 15. It is particular preferred if Oleth-20 and Steareth-21 are contained.

Further oil-in-water emulsions preferred according to the present invention are characterized in that at least one nonionic emulsifier having an HLB value in the range from 12 to 18 is contained in a total quantity from 1 to 2 wt %, preferably 1.2 to 1.8 wt %, and particularly preferably 1.4 to 1.7 wt %, based in each case on the weight of the entire emulsion.

Further oil-in-water emulsions preferred according to the present invention are characterized in that at least one nonionic emulsifier having an HLB value in the range from 3 to 6, in combination with at least one nonionic emulsifier having an HLB value in the range from 12 to 18, is contained.

Further oil-in-water emulsions preferred according to the present invention are characterized in that Steareth-2 is contained as a nonionic emulsifier having an HLB value in the range from 3 to 6, in combination with Steareth-21 and/or Oleth-20 as a nonionic emulsifier having an HLB value in the range from 12 to 18.

Oil-in-water emulsions preferred according to the present invention are characterized in that the ratio by weight of the total quantity of nonionic emulsifiers having an HLB value in the range from 3 to 6, and the total quantity of nonionic emulsifiers having an HLB value in the range from 12 to 18, is 1:2 to 1:5, preferably 1:2.5 to 1:3.5. According to the invention it is further preferred if the emulsion comprises at least one fatty acid containing 12 to 18 carbon atoms. Preferred fatty acids are selected from arachidic acid, myristic acid, oleic acid, palmitic acid and stearic acid. The total quantity of the fatty acids containing 12 to 18 carbon atoms is preferably in the range from 2 to 10% by weight, more preferably 2.5 to 7% by weight and most preferably 3 to 5 % by weight, calculated to the total weight of the emulsion.

For the cases the emulsion comprises at least stearic acid, it is preferred if the total quantity of stearic acid is in the range from 1 to 2.5% by weight, calculated to the total weight of the emulsion.

For the cases the emulsion comprises at least palmitic acid, it is preferred if the total quantity of palmitic acid is in the range from 1 to 2.5% by weight, calculated to the total weight of the emulsion.

According to the invention it is further preferred if the emulsion comprises at least one fatty alcohol containing 14 to 18 carbon atoms. The total quantity of the fatty alcohols containing 14 to 18 carbon atoms is preferably in the range from 4 to 12% by weight, more preferably 5 to 10% by weight and most preferably 5.5 to 8 % by weight, calculated to the total weight of the emulsion. Thereby it is preferred, if the fatty alcohols containing 14 to 18 carbon atoms are selected from the group consisting of stearyl alcohol and cetyl alcohol.

For the case that the emulsion comprises cetyl alcohol it is further preferred if the total quantity of cetyl alcohol is in the range from 1 to 5% by weight, more preferably 2 to 4.5 % by weight calculated to the total weight of the emulsion.

For the case that the emulsion comprises stearyl alcohol it is further preferred if the total quantity of stearyl alcohol is in the range from 1 to 5% by weight, more preferably 2 to 4.5 % by weight calculated to the total weight of the emulsion.

According to the invention the emulsion preferably comprises at least on oil component which is liquid at 20°C. Preferred oil components are selected from linear and branched saturated mono- or polyvalent C3 to C30 alkanols that are etherified with at least one propylene oxide unit per molecule, propylene glycol monoesters of branched saturated C6 to C30 alkanecarboxylic acids, and branched saturated C10 to C30 alkanols, that are liquid at 20°C. Among the oil components that are liquid at 20° C, which are selected from linear and branched saturated mono- or polyvalent Csto C30 alkanols that are etherified with at least one propylene oxide per molecule, are preferably propanol, glycerol, propylene glycol, butanol, butanediol, pentanol, decyl alcohol, capryl alcohol, caprylyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, palmityl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, and behenyl alcohol, that are etherified with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 propylene oxide units.

Particularly preferred oil-in-water emulsions according to the present invention are characterized in that PPG-3 myristyl ether (obtainable e.g., as a commercial product Witconol® APM), PPG-13 butyl ether, PPG-14 butyl ether (obtainable e.g., as a commercial product Ucon Fluid® AP), PPG-9 butyl ether (obtainable e.g., as a commercial product Breox® B25), PPG-10 butanediol (obtainable e.g., as a commercial product Macol® 57), and PPG- 15 stearyl ether (obtainable e.g., as a commercial product Arlamol® E), and mixtures thereof are contained as oil component. It is particular preferred if at least PPG-15 stearyl ether is contained.

According to the invention it is further preferred if the emulsion comprises at least one natural oil. Natural oils are preferably selected from the group consisting of helianthus annuus seed oil, canola oil, glycine soja oil, olea europaea fruit oil, prunus amygdalus dulcis oil, persea gratissima oil, junglans regia seed oil, prunus persica kernel oil, prunus armeniaca kernel oil, sesamum indicum seed oil, camelia oleifera/ camelia sasanqua, oenothera biennis, macadamia intergrifolia seed oil, silybum marianum seed oil, triticum vulgare germ oil, elaeis guineensis kernel oil, elaeis guineensis oil, vitis vinifera seed oil, argania spinosa seed oil, arachis hypogaea oil, cucurbita pepo seed oil, ricinus communis seed oil, oryza sativa bran oil, vegetable oil (Olus Oil) and coconut oil.

According to the invention it is also preferred if the emulsion comprises at least one natural butter. Natural butters are preferably selected from the group consisting of cacao butter, butyrospermum parkii butter, coconut butter, avocado butter, mango butter, babassu butter and murumuru butter.

According to the invention it is also preferred if the emulsion comprises at least one mineral oil, preferably paraffinum liquidum. It is particular preferred, if the emulsion comprises at least PPG-15 stearyl ether and paraffinum liquidum.

Generally it is preferred if the total quantity of the oils, which are liquid at 20°C and which are not an emulsifier, is in the range from 5 to 15 % by weight, more preferably 7 to 14% by weight and most preferably 9 to 13% by weight, calculated to the total weight of the emulsion.

For the case that PPG-15 stearyl ether is contained the total quantity of PPG-15 stearyl ether is preferably in the range from 3 to 10% by weight, more preferably from 4 to 9% by weight and most preferably 5 to 8% by weight calculated to the total weight of the emulsion.

For the case that paraffinum liquidum is contained the total quantity of paraffinum liquidum is preferably in the range from 2 to 8% by weight, more preferably from 3 to 7% by weight and most preferably 3.5 to 6% by weight calculated to the total weight of the emulsion.

Furthermore it is preferred if the emulsion comprises a further wax compound selected from hydrocarbon waxes, natural waxes and mineral waxes. Preferred waxes to be contained in the emulsion of the invention are selected from the group including carnauba wax, candelilla wax, ozokerite, beeswax, montan wax, wool wax, ceresiner micro-waxes and paraffin waxes. More preferred waxes are carnauba wax, candelilla wax, castor wax, olive wax, beeswax, cera microcristallina and ozokerite. It is particular preferred if the emulsion comprises cera microcristallina.

If the emulsion comprises at least one wax compound selected from hydrocarbon waxes, natural waxes and mineral waxes, it is preferred if the total quantity of those waxes is in the range from 3 to 8% by weight calculated to the total weight of the emulsion.

In particular it is preferred if the emulsion comprises from 3 to 8% by weight of cera microcristallina, whereby the value by weight is calculated to the total weight of the emulsion.

According to the invention it is also preferred if the emulsion comprises hydrogenated castor oil. If hydrogenated castor oil is contained, it is preferred if the total quantity of hydrogenated castor oil is in the range from 2 to 10% by weight, more preferably from 4 to 7% by weight, calculated to the total weight of the emulsion. Furthermore, preferred embodiments of the invention are characterized in that the emulsion comprises at least one polyol containing 2 to 3 carbon atoms. Such preferred polyols are glycerol and propylene glycol. The total quantity of at least one polyol containing 2 to 3 carbon atoms is preferably in the range from 6 to 15% by weight and more preferably 7.5 to 12% by weight, calculated to the total weight of the emulsion. If the emulsion comprises propylene glycol it is preferred if the total quantity of propylene glycol is in the range from 1 to 5% by weight and more preferably 2 to 4% by weight, calculated to the total weight of the emulsion. If the emulsion comprises glycerol it is preferred if the total quantity of glycerol is in the range from 3 to 9% by weight and more preferably 5.5 to 7.5% by weight, calculated to the total weight of the emulsion.

According to the invention it is further beneficial if the emulsion comprises at least one solid particle, which is not liquid at any temperature below 95°C, whereby it is preferred if the total quantity of such solid particles is in the range from 0.01 to 1.5% by weight. It is particularly preferred if titanium dioxide is contained as sole solid particle, whereby the total quantity of titanium dioxide is contained in the range from 0.01 to 1.5% by weight. All % by weight refer to the total weight of the emulsion.

Additionally it is preferred if the emulsion contains water in a total quantity from 25 to 52% by weight, more preferably from 30 to 48% by weight and most preferably from 37 to 44% by weight, calculated to the total weight of the emulsion.

Moreover, it is preferred if the emulsion does not contain cocam idopropyl betaine. Preferred embodiments are also characterized in that that the emulsion does not comprise any further anionic surfactants. Preferred embodiments are also characterized in that that the emulsion does not comprise any further nonionic surfactants. Preferred embodiments are also characterized in that that the emulsion does not comprise any further amphoteric surfactants.

Accordingly, it is preferred if the emulsion does not include any further anionic or amphoteric surfactant.

Furthermore, it is preferred if the emulsion of the present invention is not liquid under normal conditions. Under normal conditions the emulsion of the invention has preferably so solid appearance. In other words, the emulsion is characterized in that it solidifies under normal conditions. Accordingly the emulsion is solid under normal conditions. The present invention allows surprisingly to increase the hardness of the emulsion. According to the invention, the emulsion of the invention is preferably a solid cleansing bar.

The hardness of a solidified emulsion may be measured in the following way: A PENETROMETER PNR12 of Anton Paar brand is employed to measure the distance a needle (model 1438008, supplied with the PENETROMETER PNR12) penetrates into the solidified emulsion. Thereby, the needle is positioned vertically above the solidified emulsion with the tip pointing towards the emulsion. Then the needle is moved towards the emulsion such that it stops just before touching the emulsion. Then the needle is released such it penetrates perpendicularly into the emulsion. Depending on the hardness of the emulsion, the needle penetrates into different depth of the emulsion. The penetration depth is measured by the PENETROMETER PNR12. The measurements are carried out at 20° C. and 50% relative atmospheric humidity, the sample temperature was 20° C. The measurements were performed 24 hours after preparation of the solidified emulsion.

Examples:

The following examples should illustrate the present 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. In the case the formulations do not sum up to 100% by weight, the content is adjusted by the water content such that the formulations sums up 100% by weight.

The following compositions were prepared by mixing the ingredients at a temperature of 75°C and homogenization of the mixture at elevated temperatures. Afterwards the formed emulsions were filled into a mask to cool down and solidify under normal conditions. The hardness of the solidified emulsions was measured 24 hours after production of the solid bars. The measurement of the hardness was performed according to the description above.

The compositions Com.1 and Com.2 are reference examples which are not according to the invention. Ex.1 and Ex.2 are according to the invention. The penetration depth determined indicated that due to the use of the surfactants of the present invention, the hardness of the solidified emulsion could be increased significantly.

The penetration depth was determined using the procedure described above. The results indicate that the formulas Ex.1 to 4 show a significant higher hardness than the emulsions of the comparison examples Com.1 and Com.2. This is indicated by the fact that the needle did not penetrate as deep into the formulas of the invention. Although all formulas are solid under normal conditions, the hardness of the formulas is different.

Furthermore, it was confirmed by an expert panel that the emulsion of the present invention shows good cleansing properties. The formulations according to the invention allow for an effective dirt removal from the skin.

Claims

1. Cosmetic oil-in-water emulsion comprising a) Sodium cocoyl isethionate, and b) Sodium laureth sulfate and/or sodium stearoyl glutamate.

2. Use of a) Sodium cocoyl isethionate and b) sodium laureth sulfate and/or sodium stearoyl glutamate; in a cosmetic oil-in-water emulsion to increase the hardness of the a solidified emulsion under normal conditions.

3. Emulsion according to claim 1 or use according to claim 2 characterized in that the total quantity of Sodium cocoyl isethionate is in the range from 2 to 12%, more preferably from 4 to 10% by weight and most preferably from 6 to 9 % by weight, calculated to the total weight of the emulsion.

4. Emulsion or use according to one of the proceeding claims characterized in that sodium laureth sulfate is contained.

5. Emulsion or use according to one of the proceeding claims characterized in that the total quantity of sodium laureth sulfate and/or sodium stearoyl glutamate is in the range from 1 to 10% by weight, more preferably 3 to 8% by weight and most preferably from 4.5 to 6% by weight, calculated to the total weight of the emulsion.

6. Emulsion or use according to one of the proceeding claims characterized in that the ratio by weight between sodium cocoyl isethionate and the total quantity of sodium laureth sulfate and/or sodium stearoyl glutamate is in the range from 1:1 to 2:1, more preferably from 1.25:1 to 1.9:1 and most preferably from 1.45:1 to 1.75:1.

7. Emulsion or use according to one of the proceeding claims characterized in that at least one nonionic emulsifier having an HLB value in the range from 3 to 6 is contained.

8. Emulsion or use according to claim 7 characterized in that the nonionic emulsifier having an HLB value in the range from 3 to 6 is contained in a total quantity from 0.8 to 3% by weight, preferably 1 to 2.6% by weight, and particularly preferably 1.2 to 2.2% by weight, based in each case on the weight of the entire emulsion.

9. Emulsion or use according to one of the proceeding claims characterized in that at least one nonionic emulsifier having an HLB value in the range from 12 to 18 is contained.

10. Emulsion or use according to claim 9 characterized in that nonionic emulsifier having an HLB value in the range from 12 to 18 is contained in a total quantity from 1 to 2 wt %, preferably 1.2 to 1.8 wt %, and particularly preferably 1.4 to 1.7 wt %, based in each case on the weight of the entire emulsion.

11. Emulsion or use according to one of the proceeding claims characterized in that the ratio by weight of the total quantity of nonionic emulsifiers having an HLB value in the range from 3 to 6, and the total quantity of nonionic emulsifiers having an HLB value in the range from 12 to 18, is 1:2 to 1:5, preferably 1:2.5 to 1:3.5.

12. Emulsion or use according to one of the proceeding claims characterized in that the emulsion comprises at least one fatty acid containing 12 to 18 carbon atoms, whereby it is preferred if the total quantity of the fatty acids containing 12 to 18 carbon atoms is in the range from 2 to 10% by weight, more preferably 2.5 to 7% by weight and most preferably 3 to 5 % by weight, calculated to the total weight of the emulsion.

13. Emulsion or use according to one of the proceeding claims characterized in that the emulsion comprises at least one fatty alcohol containing 14 to 18 carbon atoms, whereby it is preferred if the total quantity of the fatty alcohols containing 14 to 18 carbon atoms is in the range from 4 to 12% by weight, more preferably 5 to 10% by weight and most preferably 5.5 to 8 % by weight, calculated to the total weight of the emulsion.

14. Emulsion or use according to one of the proceeding claims characterized in that if the emulsion contains water in a total quantity from 25 to 52% by weight, more preferably from 30 to 48% by weight and most preferably from 37 to 44% by weight, calculated to the total weight of the emulsion.

15. Emulsion or use according to one of the proceeding claims characterized in that the emulsion solidifies under normal conditions.

PAGE INTENTIONALLY LEFT BLANK