Skin cleansing composition

Abstract

Disclosed is a skin cleansing composition comprising: an anionic surfactant selected from an alkyl sulfate, an alkyl ether sulfate, or a mixture thereof; polypropylene glycol; and a diol, wherein the weight ratio of the diol to the anionic surfactant is at least 1:5.

Description

[Technical Field]

[0001] The present invention relates to a skin cleansing composition suitable for use with automated dispensing devices, particularly one that can produce a fine, uniform, and stable foam with automated dispensing devices after storage at high and low temperatures, and can leave little residue at elevated temperatures. [Background technology]

[0002] Due to their convenience and non-contact mode, automated dispensing devices have been widely used to dispense skin cleansing compositions in many locations, such as airports, hotels, and homes. Environmental temperatures can vary significantly depending on the region and / or situation. Such temperatures can affect the performance of the skin cleansing composition in the automated dispensing device. The inventors have identified several issues, such as the foam generated being less fine and dense after cold storage, and the risk of more residue forming around the nozzle of the device at high temperatures, which increases the risk of clogging the nozzle.

[0003] The present inventors have recognized the need to develop a skin cleansing composition that has a wide range of applicability at different temperatures.Therefore, it can provide consumers with an excellent cleansing experience at low temperatures, while generating less residue at high temperatures.Surprisingly, it has been found that by including polypropylene glycol and diol in a skin cleansing composition that comprises an anionic surfactant at a specific weight ratio of diol to anionic surfactant, the composition can generate fine, uniform and stable foam through an automatic dispensing device after storage at high and low temperatures, and generate less residue at high temperatures. Summary of the Invention

[0004] In a first aspect, the present invention relates to a skin cleansing composition comprising an anionic surfactant selected from alkyl sulfates, alkyl ether sulfates, or mixtures thereof; polypropylene glycol, and a diol, wherein the weight ratio of said diol to said anionic surfactant is at least 1:5.

[0005] All other aspects of the present invention will become more readily apparent in light of the following detailed description and examples. DETAILED DESCRIPTION OF THE INVENTION

[0006] Except in the examples, or where expressly indicated otherwise, all numbers in this specification expressing quantities of ingredients or reaction conditions, physical properties and / or uses of ingredients may be understood to be modified by the word "about."

[0007] Unless otherwise specified, all amounts are by weight of the composition.

[0008] It should be noted that in specifying any range of values, any particular upper limit value can be associated with any particular lower limit value.

[0009] For the avoidance of doubt, the word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive.

[0010] Regardless of whether the claims may be found without multiple dependency or redundancy, the disclosure of the invention found herein should be considered to cover all embodiments found in claims that are multiple dependent on one another.

[0011] Where a feature is disclosed with respect to a particular embodiment of the invention (e.g., a composition of the invention), such disclosure should be deemed to apply mutatis mutandis to any other embodiment of the invention (e.g., a method of the invention).

[0012] Anionic surfactants suitable for the present invention are selected from alkyl sulfates (i.e., sulfates), alkyl ether sulfates, or mixtures thereof. Preferably, the alkyl sulfates and alkyl ether sulfates have the formula R1OSO3M and R1O(C2H4O), respectively. x The compound has the formula SO3M, where each R1 is an alkyl or alkenyl of 8 to 18 carbon atoms, x is an integer having a value of 1 to 10, and each M is a cation such as ammonium, an alkanolamine such as triethanolamine, a monovalent metal such as sodium and potassium, or a polyvalent metal cation such as magnesium and calcium. More preferably, each R1 is an alkyl or alkenyl of 10 to 16 carbon atoms, x is an integer having a value of 1 to 10, and each M is a cation of triethanolamine, sodium, or potassium. Most preferably, each R1 and R2 is linear, not branched, and has 12 to 14 carbon atoms.

[0013] Typically, the anionic surfactant is selected from sodium lauryl sulfate, sodium lauryl ether sulfate, sodium trideceth sulfate, ammonium lauryl sulfate, ammonium lauryl ethyl sulfate, or a mixture thereof. Preferred anionic surfactants are selected from sodium lauryl sulfate and sodium lauryl ether sulfate (n)EO (n is 1 to 3); more preferably, sodium lauryl ether sulfate (n)EO (n is 1 to 3); and most preferably, sodium lauryl ether sulfate (n)EO (n=1).

[0014] Preferably, the total amount of alkyl sulfates and alkyl ether sulfates is preferably from 1 to 25% by weight of the composition, more preferably from 2 to 20% by weight, even more preferably from 4 to 16% by weight, even more preferably from 6 to 14% by weight.

[0015] Preferably, the polypropylene glycol contains 2 to 200, more preferably 3 to 50, and even more preferably 4 to 20 propylene oxide polymerized units. Preferably, the polypropylene glycol has a number average molecular weight of 100 to 50,000, more preferably 200 to 5,000. Most preferably, the polypropylene glycol is polypropylene glycol-7 (PPG-7).

[0016] Preferably, the polypropylene glycol is present in an amount of from 0.1 to 10%, more preferably from 0.5 to 7%, more preferably from 1 to 4% by weight of the composition.

[0017] As used herein, diol refers to an alcohol having two hydroxyl groups. Preferably, the diol has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and most preferably, the diol has 3 to 4 carbon atoms.

[0018] Particularly preferred diols include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, isoprene glycol, hexylene glycol, or a mixture thereof. More preferably, the diol includes ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, or a mixture thereof. Even more preferably, the diol includes propylene glycol, butylene glycol, or a mixture thereof. Even more preferably, the diol includes propylene glycol, and most preferably, the diol is propylene glycol. For clarity, diols are chemically different from polypropylene glycol.

[0019] Typically, the amount of diol is from 0.1 to 30% by weight, preferably from 0.5 to 20% by weight, more preferably from 1 to 15% by weight, even more preferably from 2 to 10% by weight of the total weight of the composition.

[0020] To improve the lathering property and / or feel, the weight ratio of the diol to the total amount of the alkyl sulfate and alkyl ether sulfate is preferably 1:5 to 50:1, more preferably 1:5 to 5:1, and even more preferably 1:4 to 2:1. To achieve better lathering property and / or feel, the weight ratio of the polypropylene glycol to the total amount of the alkyl sulfate and alkyl ether sulfate is preferably 1:50 to 10:1, more preferably 1:20 to 5:1, even more preferably 1:10 to 2:1, and even more preferably 1:8 to 1:1.

[0021] The composition may further comprise a monomeric alcohol. As used herein, a monomeric alcohol refers to an alcohol that is not a polymer. A monomeric alcohol is chemically distinct from diols and polypropylene glycols. Preferably, the monomer comprises glycerol (i.e., glycerin or glycerine), sorbitol, hydroxypropyl sorbitol, 1,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol, or a mixture thereof. More preferably, it comprises glycerin, sorbitol, or a mixture thereof. Even more preferably, the monomeric alcohol comprises glycerin, and most preferably, the monomeric alcohol is glycerin. Preferably, the monomeric alcohol has a molecular weight of 50 to 500, more preferably 60 to 300.

[0022] Preferably, the amount of monomeric alcohol is from 0.1 to 30% by weight, preferably from 1 to 20% by weight, more preferably from 3 to 15% by weight, even more preferably from 5 to 10% by weight of the total weight of the composition.

[0023] Preferably, the total amount of the monomeric alcohols and diols is 0.1 to 40% by weight, preferably 1 to 20% by weight, more preferably 3 to 15% by weight, and even more preferably 6 to 12% by weight of the total weight of the composition. Preferably, the weight ratio of the total weight of the monomeric alcohols and diols to the total weight of the alkyl sulfates and alkyl ether sulfates is in the range of 1:10 to 10:1, more preferably 1:6 to 6, and even more preferably 1:2 to 2:1, in order to achieve better foaming properties and / or feel.

[0024] The composition may further comprise an amphoteric surfactant, the amount of which may range from 0.5 to 8% by weight of the total composition, preferably from 1 to 4%.

[0025] Examples of amphoteric surfactants include alkylamine oxides, alkylbetaines, alkylamidopropylbetaines, alkylsulfobetaines (sultaines), alkylglycinates, alkylcarboxyglycinates, alkylamphoacetates, alkylamphopropionates, alkylamphoglycinates, alkylamidopropylhydroxysultaines, and / or acyltaurates and acylglutamates, wherein the alkyl and acyl groups have 8 to 19 carbon atoms. Representative amphoteric surfactants for use in the compositions of the present invention include laurylamine oxide, cocodimethylsulfopropylbetaine, laurylbetaine, cocamidopropylbetaine, and / or sodium cocoamphoacetate. A particularly preferred amphoteric surfactant is cocamidopropylbetaine.

[0026] Water-insoluble skin benefit agents can also be incorporated into the compositions as conditioners and moisturizers. Examples include silicone oils; hydrocarbons such as liquid paraffin, petrolatum, microcrystalline wax, and mineral oil; and vegetable triglycerides such as sunflower seed and cottonseed oil.

[0027] Some compositions may contain thickeners. These may be selected from cellulose derivatives, natural gums, and acrylic polymers, but the type of thickener is not limiting. Cellulose derivatives include sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, and combinations thereof. Suitable gums include xanthan, pectin, karaya, agar, alginate gum, and combinations thereof. Acrylic thickeners include homopolymers and copolymers of acrylic and methacrylic acid, including carbomers such as Carbopol 1382, Carbopol 982, Ultrez, Aqua SF-1, and Aqua SF-2, available from Lubrizol Corporation. The amount of thickener may range from 0.01 to 3% by weight of the active polymer (excluding solvent or water) in the composition.

[0028] Preservatives can desirably be incorporated into the compositions of the present invention to protect against the growth of potentially harmful microorganisms. A conventional preservative suitable for the compositions of the present invention is an alkyl ester of parahydroxybenzoic acid. Other preservatives that have recently come into use include hydantoin derivatives, propionate salts, and various quaternary ammonium compounds. Particularly preferred preservatives are phenoxyethanol, methylparaben, propylparaben, imidazolidinyl urea, sodium dehydroacetate, and benzyl alcohol. Preservatives should be selected taking into account the intended use of the composition and potential incompatibilities between the preservative and other ingredients. Preservatives are preferably used in amounts ranging from 0.01% to 2% by weight of the composition.

[0029] A variety of other optional ingredients can be incorporated into the composition, including antibacterial agents such as 2-hydroxy-4,2',4'-trichlorodiphenyl ether (triclosan), 2,6-dimethyl-4-hydroxychlorobenzene, and 3,4,4'-trichlorocarbanilide; scrubbing and exfoliating particles such as polyethylene and silica or alumina; cooling agents such as menthol; skin soothing agents such as aloe vera; and colorants.

[0030] Additionally, the compositions of the present invention may further comprise 0.05 to 10% by weight of a sequestering agent, such as tetrasodium ethylenediaminetetraacetic acid (EDTA), EHDP, or mixtures; an opacifier and pearlizer, such as ethylene glycol distearate, titanium dioxide, or Lytron 621 (styrene / acrylate copolymer), all of which are useful in improving the appearance and properties of the product.

[0031] The composition may comprise water in an amount of from 10 to 95% by weight of the composition, more preferably from 20 to 88%, even more preferably from 35 to 82%, and most preferably from 45 to 75%.

[0032] Preferably, the composition is mixed for about 20 seconds. -1 The composition has a viscosity of at least 5 mPa·s, more preferably 8 to 10,000 mPa·s, even more preferably 10 to 1,000 mPa·s, and most preferably 20 to 200 mPa·s, when measured at a relatively high shear rate of 1000 mPa·s at 20° C. Preferably, the composition is in the form of a fluid.

[0033] Skin cleansing composition (product) refers to a composition (product) suitable for topical application to human skin, and is preferably a rinse-off product.The term "rinse-off" used in relation to the composition herein means a composition that is applied or rubbed onto the skin and then rinsed off.The term "skin" used herein includes the skin of the face (excluding eyelids and lips), neck, chest, abdomen, back, arms, armpits, hands and feet.Preferably, "skin" refers to the skin of the face (excluding eyelids and lips) and armpits, and more preferably, skin refers to the skin of the face other than the lips and eyelids.

[0034] The following examples are provided to facilitate understanding of the present invention and are not intended to limit the scope of the claims. [Example]

[0035] Example 1 This example demonstrates the effect of propylene glycol, a diol, on foaming performance.

[0036] [Table 1]

[0037] *Ingredient levels refer to active agent levels.

[0038] A series of skin cleansing compositions were prepared according to Table 1 by following standard procedures.

[0039] The foaming performance of all samples at low temperatures was evaluated by the following procedure. Each sample was filled into an identical automatic dosing device and stored at 5°C for 15 days. An equal amount of sample was then pumped from the device onto a watch glass. The foam was observed and the foaming performance of each sample was rated in terms of richness and fineness. Foams with many large bubbles were marked "poor," fine, dense foams were marked "good," and intermediate foams were marked "fair."

[0040] The performance of the samples at high temperatures was evaluated by the following procedure: Each sample was loaded into an identical automatic dosing device. The sample was pumped from the device into a glass beaker, filling the glass beaker with foam. The glass beakers containing the samples were then placed in a 50°C oven for 7 hours. The glass beakers were then removed and observed. Samples with a lot of residue on the walls of the glass beaker were marked "fail," samples with no noticeable residue on the walls of the glass beaker were marked "good," and intermediate samples were marked "passable." The performance of all samples is recorded in Table 2.

[0041] [Table 2]

[0042] Surprisingly, it has been found that by including polypropylene glycol and a diol in a skin cleansing composition comprising an anionic surfactant at a specific weight ratio of diol to anionic surfactant, the composition is capable of producing a fine, uniform and stable foam through automated dispensing equipment even after storage at low temperatures, with much less residue at elevated temperatures.

Claims

1. (a) an anionic surfactant selected from alkyl sulfates, alkyl ether sulfates, or mixtures thereof; (b) polypropylene glycol and (c) diol 1. A skin cleansing composition comprising: the weight ratio of said diol to said anionic surfactant is at least 1:5; the weight ratio of the polypropylene glycol to the total amount of the alkyl sulfate and the alkyl ether sulfate is 1:10 to 1:1; Skin cleansing composition.

2. 2. The composition of claim 1, wherein the combined amount of said alkyl sulfate and said alkyl ether sulfate is 1 to 25 weight percent of said composition.

3. The composition described in claim 1, wherein the total amount of the alkyl sulfate and the alkyl ether sulfate is 4 to 16 weight percent of the composition.

4. 4. The composition according to claim 1, wherein the anionic surfactant is selected from sodium lauryl sulfate and sodium lauryl ether sulfate, sodium trideceth sulfate, ammonium lauryl sulfate, ammonium lauryl ethyl sulfate, or mixtures thereof.

5. The composition of any one of claims 1 to 4, wherein the polypropylene glycol is polypropylene glycol-7.

6. The composition of any one of claims 1 to 5, wherein the polypropylene glycol is present in an amount of 0.1 to 10% by weight of the composition.

7. A composition described in any one of claims 1 to 6, wherein the polypropylene glycol is present in an amount of 1 to 4 weight percent of the composition.

8. The composition of any one of claims 1 to 7, wherein the diol comprises ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, or mixtures thereof.

9. The composition of claim 1, wherein the diol comprises propylene glycol.

10. The composition according to any one of claims 1 to 9, wherein the amount of diol is from 0.1 to 30% by weight of the total weight of the composition.

11. A composition according to any one of claims 1 to 10, wherein the amount of diol is from 1 to 15% by weight of the total weight of the composition.

12. The composition according to any one of claims 1 to 11, wherein the weight ratio of the diol to the total amount of the alkyl sulfate and the alkyl ether sulfate is from 1:5 to 50:

1.

13. A composition according to any one of claims 1 to 12, wherein the weight ratio of the diol to the total amount of the alkyl sulfate and the alkyl ether sulfate is 1:4 to 2:

1.

14. The composition of any one of claims 1 to 13, wherein the composition further comprises a monomeric alcohol.

15. The composition of claim 14, wherein the monomeric alcohol is glycerin.

16. 16. The composition of claim 14 or 15, wherein the weight ratio of the total weight of the monomeric alcohol and the diol to the total weight of the alkyl sulfate and the alkyl ether sulfate is in the range of 1:10 to 10:

1.

17. A composition described in claim 14 or 15, wherein the weight ratio of the total weight of the monomer alcohol and the diol to the total weight of the alkyl sulfate and the alkyl ether sulfate is in the range of 1:2 to 2:

1.

18. 18. The composition according to any one of claims 14 to 17, wherein the total amount of monomeric alcohol and said diol is from 0.1 to 40% by weight of the total weight of the composition.

19. A composition according to any one of claims 14 to 17, wherein the total amount of the monomeric alcohol and the diol is 3 to 15 weight percent of the total weight of the composition.

20. The composition of any one of claims 1 to 19, wherein the composition comprises an amphoteric surfactant.

21. The composition of claim 20, wherein the amphoteric surfactant is cocamidopropyl betaine.

22. 22. The composition according to claim 20 or 21, wherein the amount of said amphoteric surfactant is in the range of 0.5 to 8% by weight of the total composition.

23. A composition according to any preceding claim, wherein the composition comprises from 35 to 82% water by weight of the composition.

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