An aqueous cleaning composition

Abstract

The present invention relates to an aqueous cleaning composition which is well preserved. This is especially preferred for use in a personal care or home care composition comprising a synthetic surfactant system. The composition according to the present invention comprises a group of specific carboxylic acids that suitable for use with consumer goods, particularly aqueous cleaning compositions comprising synthetic surfactant.

Description

[0001] P0001117 CPL

[0002] 1

[0003] AN AQUEOUS CLEANING COMPOSITION

[0004] Field of the Invention

[0005] The present invention is in the fields of cleaning composition. Particularly, it relates to an aqueous

[0006] 5 cleaning composition which is well preserved.

[0007] Background of the Invention

[0008] The consumer goods industry has a constant need for agents having antimicrobial properties, in particular for the preservation of products which are otherwise perishable, such as cleaning products, cosmetics, pharmaceutical products or foodstuffs.

[0009] A large number of antimicrobial active compounds are already employed in the cleaning industry, but alternatives nevertheless continue to be sought. Everyone likes to keep their home and environment as well as their bodies clean. Cleaning of homes, including clothes and other fabrics

[0010] 15 used in homes, is often classified under home care. Products for cleaning of human and animal bodies are classified under personal care. Not all antimicrobial agents have preservative properties, and thus the need for new preservation chemicals is particularly required. It is to be noted that the substances used in most of these products especially in the personal care field must be toxicologically acceptable, readily tolerated by the skin, stable in the compositions they

[0011] 20 are being incorporated in, colourless and odourless, inexpensive to prepare, have low ecological significance and be easy to formulate.

[0012] Further, it is expected that many conventional preservatives like parabens, methyl isothiazolinone (MIT), methyl chloro isothiazolinone (CIT) and hydantoins may face restrictions on their use by

[0013] 25 regulatory authorities in some countries in the years to come. Therefore, there has been a recent spate of research in identifying new preservative actives or combination of actives that provide enhanced preservative activity in inhibiting growth of microorganisms in pharmaceutical / cosmetic compositions. Additionally, such preservatives are expected to be stable in the composition, e.g. there is low change in colour of the composition over time.

[0014] 30

[0015] The present inventors have found a group of specific carboxylic acids suitable for use with consumer goods, particularly aqueous cleaning compositions comprising synthetic surfactant which is found to be well preserved at a specific pH range. The composition is cost effective and easy to formulate with compositions of the invention and is colour stable. It comprises low carbon P0001117 CPL

[0016] 2 chain length aliphatic unsaturated carboxylic acids having only one double bond in such a composition.

[0017] It is thus an objective of the present invention to provide an effectively preserved aqueous

[0018] 5 cleaning composition which is stable with respect to colour on storage over a period of time.

[0019] Summary of the Invention

[0020] The first aspect of the present invention relates to an aqueous cleaning composition comprising:

[0021] (a) 0.1 to 20 wt% of an anionic surfactant;

[0022] (b) 0.1 to 10 wt% of an amphoteric surfactant;

[0023] (c) 0.1 to 5 wt% of a C3 to C8 aliphatic unsaturated carboxylic acid having only one double bond; and

[0024] (d) 5 to 95 wt% water; wherein the composition has a pH in the range of 4.5 to 7.

[0025] 15

[0026] Another aspect of the present invention relates to a method of preserving an aqueous cleaning composition having a pH in the range of 4.5 to 7 comprising: (a) 0.1 to 20 wt% of an anionic surfactant; (b) 0.1 to 10 wt% of an amphoteric surfactant; and (c) 5 to 95 wt% water comprising the step of including therein 0.1 to 5 wt% of a C3 to C8 aliphatic unsaturated carboxylic acid

[0027] 20 having only one double bond.

[0028] Detailed Description of the Invention

[0029] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the

[0030] 25 avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. 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. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all

[0031] 30 percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific P0001117 CPL

[0032] 3 feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0033] The composition of the invention is directed to an aqueous cleaning composition. Such

[0034] 5 compositions may be a home care composition which include hard surface cleaner, laundry cleaning composition. The composition may be used to clean hard surfaces in homes like furniture, walls, floors, toilets, sinks in the kitchen and bathroom and for cleaning utensils and dishes. They may also be used for washing clothes and other fabrics in homes like curtains, bedsheets and other linen.

[0035] The composition may be a personal care composition. By a ‘personal care composition’ as used herein, is meant to include a composition for topical application i.e., external surfaces of the skin and / or hair of humans. Such a composition may be classified as leave-on or wash off, and includes any product applied to a human body for improving appearance, cleansing, odour control

[0036] 15 or general aesthetics.

[0037] The composition is preferably a wash-off composition. The composition of the present invention can be in the form of a liquid, lotion, cream, paste, emulsion, foam, or gel form. Preferred compositions include a liquid, cream, lotion, gel, or emulsion form, most preferably in liquid, lotion,

[0038] 20 or emulsion form.

[0039] "Skin" as used herein is meant to include skin on the face and body e.g., neck, chest, back, arms, underarms, hands, legs and scalp.

[0040] 25 The composition according to the present invention comprises a C3 to Cs aliphatic unsaturated carboxylic acid having only one double bond. Preferably the carboxylic acid is a C3 to Ce carboxylic acid. Carboxylic acids with only one double bond at the a, p position are most preferred. The carboxylic acids with pKa value in the range 4 to 5.5 are suitable for the present invention.

[0041] 30

[0042] Preferably the carboxylic acid is selected from acrylic acid, crotonic acid, pentenoic acid, hexenoic acid, octenoic acid, and mixtures thereof. Most preferred carboxylic acids are acrylic acid, crotonic acid, 2-pentenoic acid, 2-hexenoic acid, or their mixture. P0001117 CPL

[0043] 4

[0044] The composition comprises 0.1 to 5 wt% of the carboxylic acid. Preferably the composition comprises 0.1 to 4.5 wt%, more preferably 0.1 to 4 wt% and most preferably 0.1 to 3.5 wt% of the carboxylic acid.

[0045] 5 The composition comprises 0.1 to 20 wt% of the anionic surfactant. When the composition is formulated as a wash off composition in liquid form, it is preferred that the anionic surfactant is a soap, an isethionate, taurate, glycinate, glutamate, alkyl sulphate, a-olefin sulphonate, alkyl ether sulphate, succinate, sulphosuccinate, sarcosinate, amphoacetate, and mixtures thereof.

[0046] Preferably, the anionic surfactant is selected from alkyl ether sulphates (AES), sulphonate, taurate, isethionate, glycinate, carboxylate, and mixtures thereof. Even more preferably, alkyl ether sulphates are used as the anionic surfactant in the composition.

[0047] Examples of alkyl sulphates that may be used as anionic surfactant in the composition include

[0048] 15 sodium lauryl sulphate (SLS), sodium myristyl sulphate, and mixtures thereof. Examples of AES that may be used as anionic surfactant in the composition include sodium lauryl ether sulphate (SLES), sodium myristyl ether sulphate and sodium palmityl ether sulphate, and mixtures thereof. Preferred AES is SLES having 1 to 3 ethylene oxide units per molecule.

[0049] 20 Another class of anionic surfactants which is particularly desirable are alkyl isethionates, e.g., fatty acid esters of isethionate acid such as sodium lauroyl or sodium cocoyl isethionate, and alkyl taurate, e.g., alkyl taurate amides such as N-methyl taurate. It is especially suitable to include them as a surfactant mixture, as they have the advantage that they are sulphate-free. Further, they offer the ability to formulate isotropic systems at neutral and slightly acidic pH.

[0050] 25

[0051] As especially preferred aspect relates to compositions comprising a surfactant system which comprises (a) alkali metal acyl isethionate, (b) alkali metal alkyl taurate. Preferred isethionate sulfonates include cocoyl isethionate and lauroyl isethionate, preferably having sodium or potassium as counterions. The other preferred anionic surfactant for inclusion in the composition

[0052] 30 of the invention are alkyl taurates, e.g., alkyl taurate amides. Preferably alkyl taurate amides include sodium methyl cocoyl taurate and sodium methyl lauroyl taurate. P0001117 CPL

[0053] 5

[0054] The composition comprises 0.1 to 20 wt% of the anionic surfactant. The composition preferably comprises from 0.1 to 18 wt%, more preferably 0.2 to 16 wt%, even more preferably 0.5 to 14 wt% and most preferably 1 to 12 wt% of the anionic surfactant.

[0055] 5 The composition comprises 0.1 to 10 wt% of an amphoteric surfactant. They provide foam boost and improve the sensorials of the composition. Preferably, amphoteric surfactants are selected from the class of betaines, hydroxy sultaine, and amine oxides. Of these, the class of betaines is preferred. Preferred examples are cocamidopropyl betaine (CAPB), cocoamphoacetate, and mixtures thereof. The composition preferably comprises from 0.1 to 9 wt%, more preferably 0.2 to 8 wt%, even more preferably 0.5 to 7 wt% and most preferably 1 to 6 wt% of the amphoteric surfactant.

[0056] The weight ratio of anionic surfactant to amphoteric surfactant is preferably in the range of 2:1 to 15:1.

[0057] 15

[0058] Non-ionic surfactants may also be included in the compositions as per the invention. Preferably, the non-ionic surfactant which may be included is selected from one or more of ethanol amide, glucoside, alcohol ethoxylate, and sucrose ester. More preferred non-ionic surfactant for inclusion in the composition are selected from a fatty alcohol ethoxylates, polyoxyethylene

[0059] 20 sorbitan alkyl esters, and mixtures thereof. Another preferred non-ionic surfactant is cocamide monoethanolamide (CMEA). When included, the composition comprises 0.1 to 10 wt%, more preferably 0.25 to 7 wt% and most preferably 0.5 to 5 wt% of the non-ionic surfactant.

[0060] The composition preferably comprises a polyhydric alcohol (also called polyol) or mixture of

[0061] 25 polyols. Polyol is a term used herein to designate a compound having multiple hydroxyl groups (at least two, preferably at least three) which is highly water soluble. Many types of polyols are available including relatively low molecular weight short chain polyhydroxy compounds such as glycerol and propylene glycol; sugars such as sorbitol, mannitol, sucrose and glucose; modified carbohydrates such as dextrin and maltodextrin, and polymeric synthetic polyols such as

[0062] 30 polyalkylene glycols, for example polyoxyethylene glycol (PEG) and polyoxypropylene glycol (PPG). Especially preferred polyols are glycerol, sorbitol and their mixtures. Most preferred polyol is glycerol. Polyhydric alcohol when included, is preferably present in 0.05 to 5 wt%, more preferably 0.1 to 4 wt% and most preferably 0.5 to 3 wt% of the composition. P0001117 CPL

[0063] 6

[0064] The composition preferably comprises an electrolyte. Electrolytes as per this invention include compounds that substantially dissociate into ions in water. Electrolytes as per this invention are not an ionic surfactant. Suitable electrolytes for inclusion in the soap making process are alkali metal salts. Preferred alkali metal salts include sodium sulphate, sodium chloride, sodium

[0065] 5 acetate, sodium citrate, potassium chloride, potassium sulphate, sodium carbonate and other mono or di or tri salts of alkaline earth metals, more preferred electrolytes are sodium chloride, sodium sulphate, sodium citrate, potassium chloride and especially preferred electrolyte is sodium chloride, sodium sulphate, tri-sodium citrate, or a combination thereof. Most preferably the electrolyte is sodium chloride. For avoidance of doubt, it is clarified that the electrolyte is a non-soap material. Electrolyte is preferably included in 0.05 to 5 wt%, more preferably 0.1 to 4 wt% and most preferably 0.5 to 3 wt% by weight of the composition.

[0066] The composition comprises 5 to 95 wt% water. Preferably the composition comprises 50 to 90 wt%, more preferably 70 to 90 wt% water. The composition has a pH in the range 4.5 to 7

[0067] 15 when it is measured using a pH meter at 25°C.

[0068] Preferably, the composition may comprise small amounts of viscosity modifying polymers. Preferably, the composition comprises 0.01 to 1 wt% viscosity modifying polymers. Suitable viscosity modifying polymers are selected from water soluble / or dispersible polymers including

[0069] 20 carbohydrate gums such as modified cellulose, guar gum, modified guar gum, agar, xanthan gum, carrageenan, and mixtures thereof; starch and modified starch granules; emulsion polymers such as Aculyn® 28, Aculyn® 22 or Carbopol® Aqua SF1 ; cationic polymer such as modified polysaccharides including cationic guar. Also suitable are high molecular weight polyethylene glycols such as Polyox® WSR-205 (PEG 14M), Polyox® WSR-N-60K (PEG 45), and Polyox®

[0070] 25 WSR-301 (PEG 90M).

[0071] The compositions may further comprise a wide range of other optional components e.g., emollients, chelating agents, antioxidants, buffering agents, colorants, astringents, perfume, humectants, conditioners, pH adjusters, skin soothing agents and skin healing agents.

[0072] 30

[0073] There is provided a method a method of preserving an aqueous cleaning composition having a pH in the range of 4.5 to 7 comprising (a) 0.1 to 20 wt% of an anionic surfactant; (b) 0.1 to 10 wt% of an amphoteric surfactant; and(c) 5 to 95 wt% water, comprising the step of including P0001117 CPL

[0074] 7 therein 0.1 to 5 wt% of a C3 to C8 aliphatic unsaturated carboxylic acid having only one double bond.

[0075] The invention will now be illustrated with the help of the following non-limiting examples.

[0076] Examples

[0077] Examples were tested on following pool of microorganisms:

[0078] Table 1

[0079] 10

[0080] Ex 1 to 3 and A to C were prepared following the recipes given in Table 2:

[0081] Table 2

[0082] 15 Procedure:

[0083] Each test product was taken an amount 49.5 gm and 0.5 ml of inoculant was added, such that the final concentration in product should be 1x106to 5x106cfu / gm or log 6 for bacteria and 1x105to 5x105cfu / gm or log 5 for yeast and mould. Single inoculation was performed on day 0. At day P0001117 CPL

[0084] 8

[0085] 7, 0.5 gram was aseptically removed into a neutralizing fluid (TAT Broth) and plated using T ryptone soya agar. The plates were incubated at 30°C for 7 days. At the end of incubation time, plates were removed and examined for microbial growth. On Day 7 reinoculation was done (rechallenge) only for Pool 1 , Pool 2 and Pool M. At the end of day 14, 21 and 28 days 0.5 grams

[0086] 5 of formulation was sampled, neutralized and checked for counts. The counts were enumerated, and results were reported as log reduction.

[0087] Table 3

[0088] 10 It is evident from Table 3 that Ex 1 to 3 significantly better in reducing the growth of microorganisms compared to Ex A to C.

[0089] Further, Ex- 4 was prepared according to the recipe provided in Table 4.

[0090] Table 4

[0091] Test results for Ex 4 and D are summarised below: P0001117 CPL

[0092] 9

[0093] Table 5

[0094] The data in Table 5 indicates that the composition as per the invention (Ex 4) is superior in reducing growth of all three types of organisms tested as compared to the comparative (Ex D).

[0095] 5

[0096] Example 5, D: Effect of inclusion of carboxylic acid on colour stability of the composition Compositions as shown in Table 6 below were prepared.

[0097] Table 6

[0098] 10

[0099] The colour of the compositions was measured immediately after preparation and after 4 weeks of storage at 50°C. The L and B values were as given in Table 7 below:

[0100] Table 7

[0101] 15

[0102] The data in Table 7 read with that in Tables 2 & 3 above indicates that compositions as per the invention comprising crotonic acid deliver not only excellent preservation, but are also colour stable on storage. In contrast, a composition where sorbic acid (Example D) is used gets darker and yellower with time.

Claims

P0001117 CPL10Claims1. An aqueous cleaning composition comprising:(a) 0.1 to 20 wt% of an anionic surfactant;(b) 0.1 to 10 wt% of an amphoteric surfactant;(c) 0.1 to 5 wt% of a C3 to Cs aliphatic unsaturated carboxylic acid having only one double bond; and(d) 5 to 95 wt% water, wherein the composition has a pH in the range of 4.5 to 7.

2. A composition as claimed in claim 1 wherein the carboxylic acid is a C3 to C7 carboxylic acid.

3. A composition as claimed in claim 1 or 2 wherein the carboxylic acid has the only double bond at the a, p position.

4. A composition as claimed in any one of the preceding claims wherein the carboxylic acid has a pKa value in the range of 4 to 5.5.

5. A composition as claimed in any one of the preceding claims wherein the carboxylic acid is acrylic acid, crotonic acid, 2- pentenoic acid, 2-hexenoic acid, or mixtures thereof.

6. A composition as claimed in any one of the preceding claims wherein the anionic surfactant is an isethionate, taurate, glycinate, glutamate, alkyl sulphate, a-olefin sulphonate, alkyl ether sulphate, succinate, sulphosuccinate, sarcosinate, amphoacetate, or mixtures thereof.

7. A composition as claimed in claim 6 wherein the anionic surfactant is an alkyl ether sulphate, a-olefin sulphonate, or mixtures thereof.

8. A composition as claimed in any one of the preceding claims wherein the amphoteric surfactant is a betaine, hydroxy sultaine, amine oxide, or mixtures thereof.

9. A composition as claimed in any one of the preceding claims wherein the weight ratio of the anionic surfactant to the amphoteric surfactant is in the range of 2:1 to 15:1.P0001117 CPL1110. A composition as claimed in any one of the preceding claims comprising 0.1 to 5 wt% polyhydric alcohol.

11. A composition as claimed in claim 10 wherein the polyhydric alcohol is glycerol.

12. A composition as claimed in any one of the preceding claims comprising 0.1 to 5 wt% electrolyte.

13. A composition as claimed in claim 12 wherein the electrolyte is sodium chloride.

14. A method of preserving an aqueous cleaning composition having a pH in the range of 4.5 to 7 comprising (a) 0.1 to 20 wt% of an anionic surfactant; (b) 0.1 to 10 wt% of an amphoteric surfactant; and(c) 5 to 95 wt% water, comprising the step of including therein 0.1 to 5 wt% of a C3 to C8 aliphatic unsaturated carboxylic acid having only one double bond.

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