A SOLID CLEANSING BAR

Abstract: A solid cleansing, particularly personal care, especially shampoo, bar comprises from 70 % to 80 % by weight of a polyethylene glycol (PEG) base system having an average molecular weight between 6,500 and 8,500. The base system may comprise a mixture of PEG 6000, PEG 8000 and PEG 400. The composition includes from 12 % to 20 % by weight of a detergent which is typically a combination of an anionic surfactant (e.g. a lauryl sulphate) and an amphoteric surfactant (e.g. an imidazoline). Up to 12 % of coactive ingredients such as foam stabilisers, pearling agents, emollients and conditioners may also be present.

Description: "A solid cleansing bar" The invention relates to a solid cleansing bar in particular a bar for use as a shampoo bar, a moisturising bar, a shaving bar and detergent based products generally. Shampoos and personal care detergent products are generally provided in a liquid form. The shampoos are usually packaged in containers such as plastic bottles or sachets. Leakage can occur due to damage to the containers or failure to replace the lid effectively. Sachets are particularly prone to this leakage difficulty. Further, in use bottles of shampoo are regularly knocked or fall over when opened causing considerable wastage and causing the surfaces of baths and shower trays to become dangerously slippery. Furthermore, when the shampoo is finished, the container is discarded leading to a waste in material resources and adverse environmental effects. Another disadvantage of liquid shampoo preparations is that it is difficult to control the amount of shampoo applied to a particular area. Similar comments apply to other similar cleansing compositions. This invention is directed towards providing an approved cleansing bar which will overcome at least some of these difficulties. According to the invention there is provided a solid cleansing bar comprising a detergent; and at least 65% by weight of a polyethylene glycol base system having an average molecular weight of between 5,000 and 10,000. In a preferred embodiment of the invention the composition has a melting point of greater than 40°C. In a preferred embodiment of the invention the polyethylene glycol base system is present in an amount of between 65% and 85% by weight, most preferably between 70% and 80% by weight. In a particularly preferred arrangement the polyethylene glycol base system has an average molecular weight of between 6,500 and 8,500. In one arrangement the polyethylene glycol base system comprises at least two polyethylene glycols of different molecular weights. Typically one polyethylene glycol has a molecular weight of approximately 8,000. In one arrangement the polyethylene glycol is present in amounts of from 30% to 45%, by weight of the composition, of polyethylene glycol by a molecular weight of 6000 and from 30% to 45%, by weight of the composition, of polyethylene glycol by a molecular weight of 8,000. In one embodiment of the invention, the polyethylene glycol base system includes a softening polyethylene glycol having a molecular weight of between 100 and 800. Preferably the softening polyethylene glycol has a molecular weight of 400. Most preferably the composition includes from 1% to 8%, most preferably from 3% to 7% by weight of the softening polyethylene glycol. In a particularly preferred embodiment to the invention, the pH of a 1% solution of the composition in water is from 5.5 to 8.0, most preferably between 6.0 and 7.0. In an especially preferred embodiment to the invention, the melting point of the cleansing bar is from 43°C. to 46°C. In a particularly preferred embodiment of the invention the detergent comprises from 8% to 30% by weight of the composition. Most preferably the detergent comprises from 12% to 20% by weight of the composition. In one arrangement the detergent includes an anionic surfactant. In another arrangement the detergent includes an amphoteric surfactant. In an especially preferred embodiment of the invention the detergent is formed by a detergent system comprising at least two detergents. The anionic surfactant may preferably comprise a lauryl sulfate The amphoteric surfactant may preferably comprise an imidazoline. In one particularly preferred arrangement the detergent comprises a mixture of a lauryl sulfate and an imidazoline. In a particularly preferred embodiment the invention the composition includes up to 12% by weight of coactive ingredients. These may be selected from one or more of foam stabilisers, pearling agents, emollients, thickeners. wetting agents, superfatting agents, water binders, waxes, skin tonics and lotions, conditioners, softeners, proteins, secondary detergents and cleansing agents. In a preferred arrangement the coactive ingredients are present in an amount of from 1% to 8% by weight of the composition. In one embodiment of the invention the cleansing bar includes a betaine such as lauryl dimethyl betaine. In another embodiment of the invention the cleansing bar includes a foam stabiliser such as coconut diethanolamide. In a further embodiment of the invention the cleansing bar composition includes a conditioner such as protein collagen. In an especially preferred embodiment of the invention the cleansing bar is a shampoo bar. In another embodiment of the invention the cleansing, bar is a shaving bar. In a further embodiment to the invention the cleansing bar is a moisturising bar. The cleansing bar may also comprise a skin cleansing bar or a conditioning bar. The invention also provides a method for producing a cleansing bar according to the invention, the method comprising the steps of melting the polyethylene glycol base system, adding other ingredients and pouring the formulation thus formed into a mould at a temperature of between 55° and 68°C. In a preferred arrangement, a main detergent is first added to the melted polyethylene glycol base system prior to addition of other ingredients. The invention will be more clearly understood from the following description thereof given by way of example only. In the examples the quantities of ingredients used are given in percentage by weight of the final composition. In each case the cleansing bar composition is preferably prepared by melting the polyethylene glycol base system adding the main detergent to the melted polyethylene glycol base system, and, subsequently adding the remaining ingredients to the system during mixing. The formulation thus formed is then poured into a mould at a temperature of between 60° and 68°C and is removed from the mould after setting to provide a cleansing bar of desired size and shape. Alternatively the mould may define a container for the cleansing bar for subsequent packaging. In each case a solid cleansing bar is formed having a melting point of between 40° and 50°C and a pH in a 1% solution in water of between 6.0 and 7.0. EXAMPLE 1 Antidandruff shampoo bar 1 Polyethylene glycol 6000 40% Polyethylene glycol 8000 35% Ammonium alkyl ether sulphate 15% Coconut imidazoline 6% Cocoamidopropyl betaine 2.5% Selenium disulphide(2.5%) 1% Fragrance 0.5% EXAMPLE 2 Antidandruff shampoo bar 2 Polyethylene glycol 6000 39% Polyethylene glycol 8000 35% Sodium C 14 . 16 olefin sulphonate 13% Coconut imidazoline 6% Lauryl dimethyl betaine 3% Sodium N-lauryl sarcosinate 3.5% Octopirox 0.5% Fragrance 0.5% EXAMPLE 3 Mild shampoo bar 1 Polyethylene glycol 6000 35% Polyethylene glycol 8000 36% Lauryl ether sulphates; 13% (Sodium & magnesium lauryl ether sulphates) Coconut imidazoline 6% Polyethylene glycol 400 4% Myristyl dimethyl amine oxide 3% Sucrose monococoate 2% Fragrance 1% EXAMPLE 4 Conditioner shampoo bar Polyethylene glycol 6000 Polyethylene glycol 8000 Lauryl ether sulphates; (Sodium & magnesium lauryl ether sulphates) Sodium N-methyl cocoyl taurate Lauryl dimethyl betaine Coconut diethanolamide Quaternised hydrolysed collagen 3% Preservative 0.2% Fragrance qs EXAMPLE 5 Shaving bar (suitable for use with a shaving brush. Polyethylene glycol 6000 40% Polyethylene glycol 8000 33% Glycerol monosterate 7% Cetyl stearyl alcohol 5% Glycerol 5% Polyethylene glycol 400 4% Liquid parafin 3% Cocoamidopropyl betaine 2.5% Chlorobenzyl alcohol 0.2% Fragrance qs EXAMPLE 6 A shaving bar (brushless. Polyethylene glycol 6000 41% Polyethylene glycol 8000 36% Sodium lauryl ether sulphate 10% Lauryl Dimethyl Betaine 6% Coconut diethanolamide 4% Mineral oil 2% Silicone fluid 0.4% Preservative 0.2% Fragrance 0.4% EXAMPLE 7 Moisturising bar Polyethylene glycol 6000 40% Polyethylene glycol 8000 34% Liquid parafin & lanolin alcohol 7% Cetyl acetate & acetylate lanolin alcohol 5% Glycerol monostearate 4% Stearic acid 3% Liquid parafin 3% Propylene glycol 2% Herbal & natural extracts 2% EXAMPLE 8 Shampoo bar Polyethylene glycol 6000 33.2% Polyethylene glycol 8000 33.2% Sodium lauryl ether sulphate 26.6% Ethoxilated fatty alcohol 2.0% Quaternised hydrolysed collagen 1.3% Lauryl dimethyl betaine 2.7% Dioctyl succinate 0.4% Fragrance 0.4% The product of example 8 is prepared by mixing the polyethylene glycols and heating to 70°C. The sodium lauryl ether sulphate and the ethoxilated fatty alcohol are then added and mixing is continued. Quaternised hydrolysed collagen, lauryl dimethyl betaine, dioctyl succinate and preservative are then added, mixing is continued and the fragrance is added at 60°C. The composition is poured into a mould when mixture is in the 60° to 68°C temperature range. When the mixture has hardened the solid cleansing bar thus formed is removed from mould. EXAMPLE 9 Shampoo bar Polyethylene glycol 6000 68.3% Sodium lauryl sulphate 21.0% Hydrolysed protein 2.0% Fatty acid dialkylolamide (coconut diethanolamide) 4.0% Lauryl dimethyl betaine 4.0% Fragrance 0.5% Preservative 0.2% The polyethylene glycol is heated to 70°C and the hydrolysed protein is then added. Granular sodium lauryl sulphate is then added and dispersed with vigorous stirring for 20 minutes. The heat is removed and coconut diethanolamide and lauryl dimethyl betaine are added. The preservative and fragrance are added at 60°C, and the mixture is stirred for 10 minutes. When the mixture is in the 60° to 68°C temperature range it is poured into a mould. When hardened, the solid cleansing bar is removed from the mould. EXAMPLE 10 Skin cleansing bar Polyethylene glycol 10,000 15.0% Polyethylene glycol 8,000 20.0% Polyethylene glycol 6,000 40.0% Light mineral oil 12.0% Sucrose Tripalmitic acid 7.0% Glycerol 5.5% Fragrance and Preservative 0.5% The above examples illustrate formulations and methods for the production of a solid bar for personal use. The characteristics of the polyethylene glycol base system matrix that are necessary for incorporation in effective solid cleansing products according to the invention include the following: (a) The base system is solid with good solubility characteristics in warm water (b) Non-ionic and not sensitive to electrolytes that may be present for example in hard water. (c) Flexibility in design of tactile properties of bars for different applications. This is typically achieved bymixing different grades of polyethylene glycols. (d) The system is non volatile and thermally stable and of low reactivity. Consequently the system is stable and not reactive to many substances such as detergents and packaging materials. (e) The system is physiologically safe as it is non-toxic. It is also non-irritant and non- sensitising. This is particularly the case because the pH is close to that of the skin. (f) The system is ecologically safe and acceptable because it is biodegradable (over time) and is non-toxic to plant or animal life such as fish and bacteria. (g) The system has excellent miscibility properties with a wide range of substances (including detergents) and forms homogenous mixtures when molten or in solid form. (h) The system is mouldable when heated allowing any desired shape to be formed. (i) The system is capable of holding up to 35% of other ingredients such as detergent(s) . PEG 400 - or a similar molecular weight PEG or PEG derivative, may be included to counteract excessive drying of the product. The melting point must be greater than 40°C and preferably approximately 43°C to 46°C The pH for a 1% solution of the composition in water is preferably between 5.5 to 8, most preferably around 6.2. (In contrast, soap can be pH 9 and natural skin's pH is approximately 5.5). The second essential feature of the product is (are) the (main) detergent(s) . This is the primary active system. The main detergent is most often an anionic surfactant although amphoterics can also fulfil this role. Thus the "basic detergent" is in most cases anionic and this will represent between 8% and 30% W/W of the product. Blends of the basic detergents can also be used. Frequently used are the imidazoline with lauryl sulphates (amphoterics + anionics). The most preferred basic detergents are listed in order below:- Lauryl sulphates; TEA-, sodium-, ammonium-, magnesium Lauryl ether sulphates; sodium lauryl ether sulphate Fatty alcohol sulphates; Fatty alcohol ether sulphates; ammonium alkyl ether sulphate Sulphonates; Sodium C 14 _ι 8 olefin sulphonate Phosphates Mono alkyl sulphosuccinates; disodium lauric monoethanolamide sulphosuccinate disodium lauric ethoxy sulphosuccinate disodium undecylinic monoethanolamide sulphosuccinate disodium cocomonoethanolamide ethoxy sulphosuccinate disodium alkyl ethoxy sulphosuccinate disodium lauryl (or alkyl) sulphosuccinate Alkyl imidazoline coconut imidazoline These basic detergents are usually supplemented by coactive ingredients which include components which combine with the "basic detergent" and/or other coactive ingredients to positively contribute to the overall product performance. The coactive ingredients act, for example, as foam stabilisers, pearling agents, emollients, thickeners, wetting agents, superfatting agents, water binders, waxes, skin tonics & lotions, conditioners, softeners, proteins and secondary detergents & cleaning agents. The combinations of coactive ingredients and "basic detergents" contribute to the performance of the final products due to synergistic polar, solubility and foaming related interactions. Important coactive ingredients include those listed below but also include some of the basic detergents if found in lower concentrations. The W/W concentrations of these coactive agents is between 1% and 8% in general, although up to 12% of these coactive ingredients can be present particularly where the "basic detergent's" concentration is below 16%. These ingredients include surfactants (all types) and other recognised personal care ingredients. List of coactive ingredients Sarcoinates (sodium N-lauroyl sarcosinate) (TEA lauroyl sarcosinate) (lauroyl sarcosine) Quaternized dihydroimidazole Sodium N-methyl-N oleoyl taurates Sodium N-methyl-N cocoyl taurates Glycerol Propylene glycol Acyl N-methyl taurides Fatty esters of isethionic acid Liquid parafin Alkyl sulphoacetate Acyl glutamate Lanolin & lanolin derivatives cholesterol, lanolin, lanolin alcohols Hydrophylic oils PEG-7-glyceryl cocoate Emollient esters isostearyl neopentanoate, lauryl lactate, Fatty acid alkyolamides (mono & diamides) lauric isopropanolamide (& monoethanolamide) coconut (& lauric) diethanolamide Fatty acid esters glycerol monosterate ethylene glycol monosterate Mild teritary amino salts Proteins & hydrolysed collagens, amino acids, keratins, etc Teritary amine derivatives lauryl dimethyl betaine, lauryl (or myristyl) dimethyl amine oxide Amphoteric surfactants cocoamidopropyl betaine Nonionic surfactants sucrose monococoate Phosphate esters of fatty alcohol ethoxylates Stearic acid In addition to the coactive ingredients colours, fragrances, medicaments, antibacterial, astringents, deodorant, exfoliating and antidandruff substances may be added in concentrations generally between 0.5% and 5%. Some of these substances are listed below: Octopirox (0.5%-0.8%) Coal tar extracts (l%-5%) Herbal & natural extracts Sulphur powder Citric acid Zinc omadine (l%-2%) Selenium disulphide Zinc piridine thiol oxide Abrasives (almond & olive shell granules) (5%-15%) Dichlorobenzyl alcohols (0.2%-0.5%) Advantageously, the cleansing bar according to the present invention overcomes the leakage problems associated with shampoos which are typically provided in liquid form. Furthermore, the cleansing bar can be packaged in a biodegradable wrapper which overcomes the environmental difficulties with plastic containers and is also cheaper and less wasteful than the plastic containers. Obviously also there is no spillage problem with a solid cleansing bar and this adds to the portability of the product. Advantageously, the detergent included in the cleansing bar may be such that the bar can be used as a combined soap/shampoo bar. This would be particularly advantageous in many situations for example for travel convenience or in the hotel industry where a single cleansing bar could be provided rather than the currently used separate soap bar and shampoo sachet or container. The combined shampoo/soap bar would be less wasteful and cheaper to produce. Another advantage of bar cleansers over liquid preparations is that particular areas can be more easily targeted for higher application rates. An example of this is combination skin where some patches of skin or locations on the scalp can be more oily or drier than normal and these receive more or less application as necessary. The cleansing bar can advantageously be moulded to any desired shape or configuration, and colouring agents may also be added to the ingredients, if desired. It is envisaged that the exemplary ingredients listed above for the cleansing bar may be added to, or changed with the exception of the polyethylene glycol and detergent. As will be apparent from examples 11 and 12 below it is envisaged that solid cleansing bars including detergent for clothes washing and dishwashing supported by a polyethylene glycol carrier may be provided. Typically, a pre-set measured amount of detergent would be contained in each bar, the amount being typically a unit amount required for a particular cleaning operation. Thus, a cleansing bar with the required amount of detergent to clean a single load of clothes in a clothes washer, or for cleaning a load of dishes in a dish washer for example, may be provided. EXAMPLE 11 Solid dishwashing detergent Polyethylene glycol 8000 54% Detergent 20% Fatty acid dialkylolamide 3% Ammonium non-oxynol-4-sulphate 19% Sodium xylene sulphonate 4% Heat the polyethylene glycol 8000 to 75°C and incorporate the other ingredients individually blending each fully. allow to cool and pour into mould at approximately 60°C. EXAMPLE 12 Laundry wash bar Polyethylene glycol 6000 76% Phosphate ester surfactant 6% Tetra potassium pyrophosphate 5% Dipropylene glycol monomethyl ether 3% Additives 10% Method of manufacture similar to that described for Example 11 above. The invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Claims: CLAIMS A solid cleansing bar composition comprising: a detergent; and at least 65% by weight of a polyethylene glycol base system having an average molecular weight of between 5,000 and 10,000; A solid cleansing bar as claimed in claim 1 wherein the composition has a melting point of greater than 40°C. A cleansing bar composition as claimed in claim 1 or 2 wherein the polyethylene glycol base system is present in an amount of between 65% and 85% by weight. A cleansing bar composition as claimed in any preceding claim wherein the polyethylene glycol base system is present in an amount of between 70% and 80% by weight. A cleansing bar composition as claimed in any preceding claim wherein the polyethylene glycol base system has an average molecular weight of between 6,500 and 8,500. A cleansing bar composition as claimed in any preceding claim wherein the polyethylene glycol base system comprises at least two grades of polyethylene glycols of different molecular weights. 7. A cleansing bar composition as claimed in claim 6 wherein one polyethylene glycol has a molecular weight of approximately 6,000 and another polyethylene glycol has a molecular weight of approximately 8,000. 8. A cleansing bar composition as claimed in claim 7 wherein the polyethylene glycols are present in amounts of between 30% to 45%, by weight of the composition, of polyethylene glycol having a molecular weight of 6,000 and from 30% to 45%, by weight of the composition, of polyethylene glycol having a molecular weight of 8,000. 9. A cleansing bar composition as claimed in any preceding claim wherein the polyethylene glycol base system includes a softening polyethylene glycol having a molecular weight of between 100 and 800. 10. A cleansing bar composition as claimed in claim 9 wherein the softening polyethylene glycol has a molecular weight of 400. 11. A cleansing bar as claimed in claim 9 or 10 wherein the composition includes from 1% to 8% by weight of the softening polyethylene glycol. 12. A cleansing bar composition as claimed in any of claims 9 to 11 wherein the composition includes from 3% to 7% by weight of the softening polyethylene glycol. 13. A cleansing bar composition as claimed in any preceding claims wherein the pH of a 1% solution of the composition in water is from 5.5 to 8.0. 14. A cleansing bar composition as claimed in claim 13 when the pH is approximately 6.0 to 7.0. 15 A cleansing bar composition as claimed in any preceding claim wherein the melting point of the composition is approximately 43°C to 46°C. 16. A cleansing bar composition as claimed in any preceding claim wherein the detergent comprises from 8% to 30% by weight of the composition. 17. A cleansing bar composition as claimed in claim 16 wherein the detergent comprises from 12% to 20% by weight of the composition. 18. A cleansing bar composition as claimed in any preceding claim wherein the detergent is formed by a detergent system comprising at least two detergents. 19. A cleansing bar composition as claimed in any preceding claim wherein the detergent includes an anionic surfactant. 20. A cleansing bar composition as claimed in any preceding claim wherein the detergent includes an amphoteric surfactant. 21. A cleansing bar composition as claimed in claim 19 wherein the anionic surfactant comprises a lauryl sulphate. 22. A cleansing bar composition as claimed in claim 20 wherein the amphoteric surfactant comprises an imidazoline. 23. A cleansing bar composition as claimed in any preceding claim wherein the detergent comprises a lauryl sulphate and an imidazoline. 24. A cleansing bar composition as claimed in any preceding claim wherein the composition includes up to 12% by weight of coactive ingredients. 25. A cleansing bar composition as claimed in claim 24 wherein the coactive ingredients are selected from one or more of foam stabilisers, pearling agents, emollients, thickeners, wetting agents, superfatting agents, water binders, waxes, skin tonics and lotions, conditioners, softeners, proteins, secondary detergents and cleaning agents. 26. A cleansing bar composition as claimed in claim 23 or claim 25 wherein the coactive ingredients are present in an amount of from 1% to 8% by weight of the composition. 2 . A cleansing bar composition as claimed in any preceding claim wherein the cleansing bar includes a betaine such as lauryl dimethyl betaine. 28. A cleansing bar composition as claimed in any preceding claim including a foam stabiliser such as coconut diethanolamide. 29. A cleansing bar composition as claimed in any preceding claim including a conditioner such as protein collagen. 30. A cleansing bar composition as claimed in any • preceding claim wherein the cleansing bar is a shampoo bar. 31. A cleansing bar composition as claimed in any of claims 1 to 29 wherein the cleansing bar is a shaving bar. 32. A cleansing bar composition as claimed in any of claims 1 to 29 wherein the cleansing bar is a moisturising bar. 33. A cleansing bar composition as claimed in any of claims 1 to 29 wherein the cleansing bar comprises a conditioning bar. 34. A cleansing bar composition as claimed in any of claims 1 to 29 wherein the cleansing bar comprises a skin cleansing bar. 35. A cleansing bar composition substantially as hereinbefore described with reference to the examples. 36. A method for producing a cleansing bar as claimed in any preceding claim comprising the steps of melting the polyethylene glycol base system, adding other ingredients and pouring the formulation thus formed into a mould at a temperature of between 55° and 68°C. 37. A method as claimed in claim 36 wherein a main detergent is first added to the melted polyethylene glycol base system prior to addition of other ingredients. 38. A method for producing a cleansing bar substantially as hereinbefore described with reference to the examples. 39. A cleansing bar whenever produced by a method as claimed in any of claims 36 to 38.

Inventors: MORAN DIARMUID, MORAN THOMAS FRANCIS, O'BRIAIN BRIAN, MORAN, DIARMUID, MORAN, THOMAS, FRANCIS, O'BRIAIN, BRIAN
Applicants: NEPHIN
Application year: 1992
Main classification: A61K7
IPC codes: A61K8, A61Q5, C11D1, C11D3, C11D17