The present invention relates to aqueous cleaning compositions e.g. for cleaning hard surfaces. More particularly, the present invention relates to self-thickened aqueous cleaning compositions comprising a specific combination of surfactants.

An important feature of cleaning compositions such as hand dishwashing compositions is that they should have a certain consistency or viscosity. The desired viscosity, expected by the consumer, should not be too thin. The consumer desires viscous formulations allowing a controlled handling (providing good pourability and ease of dissolution in water). Also, the consumer associates viscous cleaning compositions with good performance and quality as well as with high levels of active ingredients.

Usually, high viscous cleaning compositions are achieved by incorporating gums, polymeric thickeners and/or high levels of salts and/or active matter of surfactants into the cleaning compositions. This technique has at least one drawback that it negatively affects the formula costs while providing no benefit (apart from thickening).

In addition, this technique is not sustainable, since cleaning formulations with high levels of polymeric thickeners and/or surfactants have an increased impact to the environment.

It is known in the art to formulate so-called self-thickened cleaning compositions where thickening is achieved without the use of polymeric thickeners, see for instance WO 95/03302, EP 839898. WO 95/03302 discloses aqueous viscous compositions comprising an amine oxide or an amine, a secondary or primary monobranched alkyl sulfate or sulfonate, a hydrotrope and an organic acid.

EP 839898 discloses aqueous viscous compositions comprising linear alcohols and/or linear alkoxylated alcohols, a hydrotropic solvent and anionic surfactants.

However, there is still a need to provide self-thickened aqueous high-viscous cleaning compositions with better performance in several respects including cleaning performance and lather performance.

It is thus object of the present invention to provide an aqueous cleaning composition such as a hard-surface cleaning composition which is highly viscous (jelly like) by means of a self- thickening system and which delivers improved cleaning performance (degreasing performance), lather performance (rapid generation of foam, stability of the foam) and solubility in water. It is thus another object of the present invention to provide an aqueous cleaning composition such as a hard-surface cleaning composition with improved mildness (softness on hands).

It is thus another object of the present invention is to provide aqueous cleaning compositions that have a reduced impact to the environment.

Finally, another object of the present invention is to provide aqueous cleaning compositions that are transparent.

We have found that the above objects can be met by combining low levels of two different anionic surfactants and one amphoteric surfactant in an aqueous medium.

Provided is a self-thickened, aqueous cleaning composition comprising

a) 3 to 10% by weight of the total composition of at least one surfactant represented by the following formula

R -0-((CH ₂ ) _m O) _n -S0 ₃ X ⁺ (I),

b) at least one surfactant represented by the following formula

R ² -A-S0 ₃ ^" Y ⁺ (II), and

c) at least one surfactant represented by the following formula

R ³ -CONH-(CH ₂ )o-N ⁺ (CH3)2-CH ₂ COO ^" (III),

wherein

R , R ² , R ³ are each independently, a linear or branched, substituted or unsubstituted alkyl-, aryl- or alkylarylgroup,

A is -O- or a chemical bonding,

m is 2 or 3,

n is an integer of from 0 to 8, preferably from 1 to 6,

o is an integer of from 1 to 4, preferably 3, and

X and Y are each independently salt forming cations sufficient to satisfy charge balance, and wherein the total amount of surfactants in the cleaning composition is < 30% by weight of the total composition.

Also provided is the use of

a) 3 to 10% by weight of the total composition of at least one surfactant represented by the following formula

R -0-((CH ₂ ) _m O) _n -S0 ₃ X ⁺ (I),

b) 3 to 10% by weight of the total composition of at least one surfactant represented by the following formula

R ² -A-S0 ₃ ^" Y ⁺ (II), and c) 3 to 10% by weight of the total composition of at least one surfactant represented by the following formula

R ³ -CONH-(CH ₂ )o-N ⁺ (CH3)2-CH ₂ COO ^" (III),

wherein

R , R ² , R ³ are each independently, a linear or branched, substituted or unsubstituted alkyl-, aryl- or alkylarylgroup,

A is -O- or a chemical bonding,

m is 2 or 3,

n is an integer of from 0 to 8, preferably from 1 to 6,

o is an integer of from 1 to 4, preferably 3, and

X and Y are each independently salt forming cations sufficient to satisfy charge balance, as a self-thickening surfactant system for aqueous cleaning compositions.

The compositions of the present invention are aqueous compositions, preferably comprising at least 70%, more preferably at least 75% and most preferably at least 80% by weight of the total composition of water.

Optionally, the compositions of the present invention may further comprise up to 10%, preferably up to 7,5% and more preferably up to 5% by weight of the total composition of an alcohol.

Suitable alcohols to be used according to the present invention are linear or branched C C ₈ - alcohols, preferably ethanol, propanol-1 , propanol-2, 2-Methylpropanol, propylene glycol-1 ,2, glycerin, polyethylene glycol, sorbitol, benzyl alcohol, phenoxy ethanol and mixtures thereof. Ethanol is most preferred .

As a second essential ingredient, the compositions of the present invention comprise 3 to 10% by weight of the total composition of at least one surfactant represented by the following formula R -0-((CH ₂ ) _m O) _n -S0 ₃ X ⁺ (I),

wherein

R is a linear or branched, substituted or unsubstituted alkyl-, aryl- or alkylarylgroup, m is 2 or 3,

n is an integer of from 0 to 8, preferably from 1 to 6, and

X is a salt forming cation sufficient to satisfy charge balance.

Preferred surfactants represented by formula (I) are alkyl(ether)sulfates wherein

R is a linear or branched, substituted or unsubstituted alkyl group comprising 8 to 30, preferably 10 to 18 and most preferably 12 to 14 carbon atoms,

m is 2,

n is an integer of from 1 to 6, preferably from 2 to 4, and X is a salt forming cation selected from sodium, potassium, ammonium, magnesium and mono-, di- or tri-C2-C3-alcanolammonium, with the sodium, magnesium and ammonium cations being preferred .

Particularly preferred surfactants represented by formula (I) are sodium or magnesium salts of linear or branched lauryl, tridecyl or myristyl sulfates with 2 to 4 moles of ethylene oxide.

The amount of surfactant(s) represented by formula (I) may vary depending on the amount of other ingredients herein, but suitable amounts of surfactant(s) represented by formula (I) herein are generally comprised between 3% and 10% by weight of the total composition.

Preferably, the amount of surfactant(s) represented by formula (I) (particularly of surfactants of formula (I), wherein R is a linear or branched Ci ₀ -Ci ₈ -alkylgroup, preferably a Ci ₂ -Ci ₄ -alkylgroup, m is 2, n is an integer of from 2 to 4 and X is a sodium, magnesium or ammonium cation) herein comprised between 3,25% and 8% by weight of the total composition and most preferably between 3,5% to 6,5%.

As a third essential ingredient, the compositions of the present invention comprise at least one surfactant represented by the following formula

R ² -A-S0 ₃ ^" Y ⁺ (II),

wherein

R ² is a linear or branched, substituted or unsubstituted alkyl-, aryl- or alkylarylgroup, A is -O- or a chemical bonding, and

Y is a salt forming cation sufficient to satisfy charge balance, preferably selected from sodium, potassium, ammonium, magnesium and mono-, di- or tri-C2-C3-alcanolammonium, with the sodium, magnesium and ammonium cations being most preferred.

Preferred surfactants represented by formula (II) are those wherein

R ² is a C ₈ -Ci ₈ -alkyl- or an C ₈ -Ci ₈ -alkylarylgroup, preferably a linear C ₉ -Ci ₃ -alkylarylgroup, and A is a chemical bonding.

Particularly preferred surfactants represented by formula (II) are sodium or ammonium salts of linear C ₉ -Ci ₃ -alkylbenzenesulfonic acid , e.g. Dodecylbenzensulfonic acid, sodium salt.

The amount of surfactant(s) represented by formula (II) may vary depending on the amount of other ingredients herein, but suitable amounts of surfactant(s) represented by formula (II) herein are generally comprised between 3% and 10% by weight of the total composition.

Preferably, the amount of surfactant(s) represented by formula (I I) herein comprised between 3,25% and 8% by weight of the total composition and most preferably between 3,5% to 6,5%.

As a fourth essential ingredient, the compositions of the present invention comprise at least one surfactant represented by the following formula

R ³ -CONH-(CH ₂ )o-N ⁺ (CH3)2-CH ₂ COO ^" (III),

wherein

R ³ is a linear or branched, substituted or unsubstituted alkyl-, aryl- or alkylarylgroup, and o is an integer of from 1 to 4, preferably 3.

Preferred surfactants represented by formula (III) are those wherein

R ³ is a linear or branched, substituted or unsubstituted C ₈ -Ci ₈ -alkylgroup, preferably an alkylgroup which is derived from coconut oil, and

o is 3.

Particularly preferred surfactants represented by formula (III) are known under the INCI name cocamidopropylbetaine. They are commercially available under the series "Tego Betaine ^® " from Evonik, "Genagen ^® " from Clariant, "Rewoteric ^® " from Goldschmidt, "Miranol ^® " from Rhodia, "Galaxy ^® " from Galaxy Surfactants or "Dehyton ^® " from BASF.

The amount of surfactant(s) represented by formula (III) may vary depending on the amount of other ingredients herein, but suitable amounts of surfactant(s) represented by formula (III) herein are generally comprised between 3% and 10% by weight of the total composition.

Preferably, the amount of surfactant(s) represented by formula (III) herein

comprised between 3,25% and 8% by weight of the total composition and most preferably between 3,5% to 6,5%.

The total amount of surfactants in the cleaning compositions of the present invention is < 30% by weight of the total composition.

Preferably, the total amount of surfactants in the cleaning compositions of the present invention is < 25%, more preferably < 20%, even more preferably < 17,5% and most preferably < 15% by weight of the total composition.

Despite their high degree of both physical and chemical stability, the cleaning compositions according to the present invention are notable for a low level of formulation complexity. This low degree of complexity simplifies manufacture of the cleaning compositions and thus reduces the costs occurring in the context of preparation of these cleaning compositions. Preferred cleaning compositions according to the present invention are, for this reason, characterized in that alongside the essential constituents a), b) and c) they comprise at most three, by preference at most two, particularly preferably at most one, and in particular no further constituents having washing or cleaning activity. The weight proportion of further ingredients having washing or cleaning activity is by preference equal to less than 5 wt %, by preference less than 4 wt %, particularly preferably less than 2,5 wt %, and very particularly preferably less than 1 .0 wt %.

If present, further ingredients having washing or cleaning activity are preferably selected from nonionic surfactants. The inventive product therefore may additionally comprise one or more nonionic surfactants, typically in an amount of from 0.001 to 5% by weight, preferably from 0.005 to 4% by weight, in particular from 0.01 to 3% by weight, more preferably from 0.05 to 2% by weight, exceptionally preferably from 0.1 to 1 % by weight of the total amount of the composition.

In the context of the invention, nonionic surfactants may be alkoxylates such as polyglycol ethers, fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, end group-capped polyglycol ethers, mixed ethers and hydroxy mixed ethers and fatty acid polyglycol esters. It is likewise possible to use ethylene oxide-propylene oxide block polymers, fatty acid alkanolamides and fatty acid polyglycol ethers. Important classes of nonionic surfactants which can be used in accordance with the invention are also the amine oxides and the sugar surfactants (polyol surfactants) and, among these, particularly the glyco-surfactants such as alkylpolyglycosides and fatty acid glucamides. Particular preference is given to the alkylpolyglycosides, especially the

alkylpolyglucosides.

Particularly preferred fatty alcohol polyglycol ethers are C12-14-fatty alcohol ethoxylates having 2, 3 or 4 EO or a mixture of the C12-14-fatty alcohol ethoxylates with 3 and 4 EO in a weight ratio of 1 to 1 or isotridecyl alcohol ethoxylate having 5, 8 or 12 EO.

Preferred amine oxides include alkylamine oxides, in particular alkyldimethylamine oxides, alkylamido amine oxides and alkoxyalkyi amine oxides. A particularly preferred amine oxide is, for example, Cocamidopropylamine Oxide.

Preferred sugar surfactants are, for example, the sugar surfactant classes of the alkylglucose esters, aldobionamides, gluconamides (sugar acid amides), glyceramides, glyceroglycolipids, polyhydroxy fatty acid amide sugar surfactants (sugar amides) and alkylpolyglycosides, as described, for instance, in WO 97/00609 (Henkel Corporation) and the documents cited therein (pages 4 to 12), to which reference is made in this regard and whose contents are incorporated into this application. In the context of the inventive teaching, preferred sugar surfactants are the alkylpolyglycosides and the sugar amides and also derivatives thereof, in particular their ethers and esters. Alkylpolyglycosides (APG) are particularly preferred sugar surfactants in the context of the inventive teaching and preferably satisfy the general formula R10(AO)a[G]x in which R1 is a linear or branched, saturated or unsaturated alkyl radical having from 6 to 22, preferably from 6 to 18, in particular from 8 to 16, more preferably from 8 to 14, carbon atoms, [G] is a glycoside- attached sugar residue and x is a number from 1 to 10 and AO is an alkyleneoxy group, for example an ethyleneoxy or propyleneoxy group, and a is the average degree of alkoxylation of from 0 to 20. The (AO)a group may also contain different alkyleneoxy units, for example ethyleneoxy or propyleneoxy units, in which case a is then the average total degree of alkoxylation, i.e. the sum of degree of ethoxylation and degree of propoxylation. Unless stated in more detail or otherwise hereinbelow, the alkyl radicals R1 of the APG are linear unsaturated radicals having the specified number of carbon atoms.

The index number x specifies the degree of oligomerization (average degree of polymerization), i.e. the distribution of mono- and oligoglycosides, and is a number between 1 and 10. While x in a given compound always has to be an integer and here in particular may assume the values x=from 1 to 6, the x value for a certain alkylglycoside is an, analytically determined calculated parameter which is usually a fraction. Preference is given to using alkylglycosides having an average degree of oligomerization x of from 1.1 to 3.0. From an application point of view, preference is given to those alkylglycosides whose degree of oligomerization is less than 1 .7 and is in particular between 1.2 and 1 .6. The glycosidic sugars used are preferably xylose, but in particular glucose.

The alkyl or alkenyl radical R1 may derive from primary alcohols having from 8 to 18, preferably from 8 to 14, carbon atoms. Particularly preferred APGs are not alkoxylated (a=0) and satisfy formula RO[G]x in which R, as before, is a linear or branched, saturated or unsaturated alkyl radical having from 4 to 22 carbon atoms, [G] is a glycoside-attached sugar radical, preferably glucose radical, and x is a number from 1 to 10, preferably from 1.1 to 3, in particular from 1 .2 to 1 .6. Accordingly, preferred alkylpolyglycosides are, for example, C8-10 - and a C12-14- alkylpolyglucoside having an average degree of polymerization of 1 .4 or 1 .5, in particular C8-10- alkyl 1 ,5-glucoside and C12-14-alkyl 1 ,4-glucoside.

The surfactants a), b), c) (represented by the formulas (I), (II) and (III)) may generally be used in any weight ratio in the cleaning compositions according to the present invention.

However, it has been found to be beneficial for the viscosity of the cleaning compositions if the surfactants a), b), c) are used in a weight ratio of approximately 1 : 1 : 1.

In a preferred embodiment the cleaning compositions according to the present invention therefore comprise the surfactants a), b), c) in a weight ratio of approximately 1 : 1 : 1 .

Particularly preferred cleaning compositions according to the present invention comprise

a) 3,5 to 6%, preferably 3,75 to 5,5% and most preferably 4 to 5% by weight of the total composition of a Sodium or Ammonium salt of an Ci ₂ -Ci ₄ -Alkyl ether sulfate (2EO), b) 3,5 to 6%, preferably 3,75 to 5,5% and most preferably 4 to 5% by weight of the total composition of a linear Sodium or Ammonium salt of C ₉ -Ci ₃ -Alkylbenzenesulfonic acid and

c) 3,5 to 6%, preferably 3,75 to 5,5% and most preferably 4 to 5% by weight of the total composition of Cocoamidopropylbetaine.

The cleaning compositions according to the present invention are preferably highly viscous (jellylike), which means that they preferably have a viscosity of from 100,000 to 200,000 mPas, more preferably of from 1 10,000 to 180,000 mPas and particularly of from 120,000 to 160,000 mPas (as measured at 20°C with a Brookfield Viscosimeter DV-II + Pro RV, spindle 2, RPM 0,3).

It is a benefit of the present invention to provide highly-viscous (jelly-like) cleaning compositions solely by combining relatively low amounts of three specific surfactants (a), b) and c)) in an aqueous medium.

It is not necessary to include high amounts of surfactants, polymeric thickeners and/or electrolytic salts into the cleaning compositions according to the present invention in order to achieve the aforementioned viscosities.

In another preferred embodiment the cleaning compositions of the present invention therefore comprise not more than 0,1 %, more preferably not more than 0,05%, even more preferably not more than 0,01 % by weight of the total composition of polymeric and/or associative thickeners. Most preferably the cleaning compositions of the present invention are free from any polymeric and/or associative thickeners.

In a further preferred embodiment the cleaning compositions of the present invention comprise not more than 1 ,5%, preferably not more than 1 ,3% even more preferably not more than 1 ,1 % and particularly not more than 1 % by weight of the total composition of electrolytic salts.

Suitable electrolytic salts which may be included in small amounts into the cleaning compositions of the present invention may be selected form alkali metal salts, preferably from sodium chloride and/or sodium sulfate.

In a further preferred embodiment the cleaning compositions of the present invention the cleaning compositions of the present invention are substantially transparent.

In the context of this invention, a "substantially transparent" product has a transmittance of light of any wavelengths in the visible range, i.e. between 400 and 800 nm, of at least 50%, measured in a cuvette with a layer thickness of 1 cm in the absence of dyes and abrasive particles. The light transmission is preferably above 70%, more preferably above 80%, in particular above 90%. In addition to the components described above, and water, the cleaning compositions according to the present invention may contain further ingredients to make the cleaning compositions of the present invention more attractive, for example active substances from the group of the scents and/or dyes not having washing or cleaning activity.

Individual perfume or fragrance compounds, e.g. the synthetic products of the ester, ether, aldehyde, ketone, alcohol, and hydrocarbon types, can be used in the context of the present invention as perfume oils or scents. Preferably, however, mixtures of different fragrances that together produce an attractive scent note are used. Such perfume oils can also contain natural fragrance mixtures such as those accessible from plant sources, e.g. pine, citrus, jasmine, patchouli, rose, or ylang-ylang oil.

Compositions herein typically comprise from 0,1 % to 2% by weight of the total composition of a perfume ingredient, or mixtures thereof, preferably from 0,1 % to 1 %.

Preferred dyes, the selection of which will present no difficulty whatsoever to the skilled artisan, possess excellent shelf stability and insensitivity to the other ingredients of the agents and to light, and no pronounced substantivity with respect to the substrates, for example textiles, glass, ceramic, or plastic tableware, to be treated with the dye-containing agents, in order not to color them.

Additional optional ingredients may be included to provide added effect to the cleaning compositions of the present invention. Such ingredients include, but are not limited to, abrasive agents, skin conditioning agents, vitamins, plant extracts, disinfectants, radical scavengers, bleaches, chelating agents, antibacterial agents/preservatives, optical brighteners, or combinations thereof.

In some embodiments, preservatives can be used in the cleaning compositions of the present invention at a concentration of 0% to 3%, more preferably 0.01 % to 2.5% by weight of the total composition.

Examples of suitable preservatives include, but are not limited to, benzalkonium chloride;

benzethonium chloride, 5-bromo-5-nitro-1 ,3-dioxane, 2-bromo-2-nitropropane-1 ,3-diol, a Iky I trimethyl ammonium bromide, N-(hydroxymethyl)-N-(1 ,3 -di hydroxy methyl-2 , 5-d ioxo-4- imidaxolidinyl-N'-(hydroxy methyl) urea, 1 ,3-dimethyol-5,5-dimethyl hydantoin, formaldehyde, iodopropynl butyl carbamate, betrix, butyl paraben, ethyl paraben, methyl paraben, propyl paraben, mixture of methyl isothiazolinone/methyl-chloroisothiazoline in a 1 :3 wt. ratio, mixture of phenoxythanol/butyl para ben/methyl paraben propylparaben, 2-phenoxyethanol, tris- hydroxyethyl-hexahydrotriazine, methylisothiazolinone, 5-chloro-2-methyl-4-isothiazolin-3-one, 1 ,2-dibromo-2,4- dicyanobutane; 1 -(3-chloroalkyl)-3,5J-triaza-azoniaadamantane chloride, and sodium benzoate.

The cleaning compositions of the present invention may be used in a wide range of applications in bathrooms, kitchens and/or floors.

In one preferred embodiment the cleaning compositions according to the present invention is a cleaning composition for hard surfaces, preferably a hand dishwashing composition.

For achieving optimal mildness, preferred cleaning compositions according to the present invention have a pH of from 4 to 9, preferably from 5 to 8,5 and more preferably of from 6 to 8.

An advantage of the highly viscous cleaning compositions according to the present invention is that they are self-thickening and do not require the presence of polymers and/or electrolyte salts (= sustainable approach to achieve highly viscous compositions).

An additional benefit derived from said cleaning compositions is that they meet the consumer requirements concerning a good cleaning performance, particularly a good fat degreasing performance.

Yet another advantage of the compositions of the present invention is that they are physically and chemically stable upon long storage periods.

Furthermore the present invention provides cost effective, mild cleaning compositions that are easily dilutable or soluble in water.

The compositions of the present invention can be made by simple mixing methods from readily available components which, on storage, do not adversely affect the entire composition. Mixing can be done by any mixer that forms the composition.

Examples

The present invention is further illustrated by the following example and data.

The cleaning composition is made by mixing the listed ingredients in the listed proportions in the following order of addition:

Firstly, the linear dodecylbenzenesulfonate, sodium salt is mixed with water in a conventional mixer (50 rpm). After 5 min. of stirring the pH value of the mixture is adjusted to 6-8 and the lauryl ether sulfate (2 EO), sodium salt is added. After 10 min. of stirring, a premix A, comprising the perfume, preservatives and ethanol is added while stirring for another 5 minutes. Then premix B is added to the mixture, comprising the dyes and water. After another 5 minutes of stirring cocamidopropylbetaine is added.

The above cleaning composition is a self-thickening aqueous composition according to the present invention which exhibits good physical stability (after at least 12 weeks of storage). The composition is jelly-like (with a viscosity of 145,000 ± 20,000 mPas, as measured at 20°C with a Brookfield Viscosimeter DV-II + Pro RV, spindle 2, RPM 0,3), transparent, easily dilutable/soluble in water and provides notably improved cleaning performance. Compared to market products, the cleaning composition according to the present invention showed improved grease removal and lather, more shininess and improved softness on the skin.