An aqueous liquid detergent composition comprising rhamnolipid biosurfactant

Abstract

The present invention relates to aqueous liquid detergent compositions comprising: a surfactant system comprising: - from 4 to 8 wt% of a surfactant system comprising: (i) a primary surfactant mix comprising alkyl ether sulfate surfactant, alkyl sulfate surfactant and a rhamnolipid biosurfactant; and (ii) a secondary surfactant mix comprising an amphoteric surfactant selected from betaines, glucamides and sultaines; - from 0.001 to 0.2 wt% of polyethylene oxide having a molecular weight higher than 200,000 g / mol; and - an inorganic salt selected from sodium chloride, magnesium sulphate and sodium sulphate; wherein - the weight ratio of (alkyl ether sulfate surfactant + alkyl sulfate surfactant + rhamnolipid biosurfactant) / amphoteric surfactant is from 1 to 4; - the percentage of secondary surfactant mix calculated on total amount of surfactant system including secondary surfactant is from 10 to 30; and - the average EO of alkyl ether sulfate surfactant and alkyl sulfate surfactant combined is from 0.45 to 1.

Description

[0001] An Aqueous Liquid Detergent Composition Comprising Rhamnolipid Biosurfactant

[0002] Field of the Invention

[0003] The present invention relates to aqueous liquid detergent compositions comprising rhamnolipid biosurfactant and a cleaning polymer, in particular a hand dishwash liquid detergent compositions comprising a surfactant system providing for easier formulation principles to achieve a desired viscosity whilst maintaining a consumer appealing product appearance.

[0004] Background of the Invention

[0005] Household cleaning activities involve the use of a detergent product and often water to rinse-off the detergent product and finish the cleaning process. These activities are typically performed daily, often more than once a day, such as dish washing. That is, hard surface cleaning, dishwashing and other household cleaning activities are time consuming activities and, ideally, can be optimized when using products with improved cleaning performance.

[0006] A cleaning product often comprises a surfactant system containing different types of surfactants to provide for cleaning efficacy. Therefore, some cleaning products contain a main surfactant, sometimes referred to as primary surfactant, and further surfactant, sometimes referred to as co-surfactant or secondary surfactant.

[0007] Consumers are interested in the sensorial experience of a detergent product and it's use in the washing process, both during and immediately after use, like for example the lasting sensorial impression left on the hands. This is important as the handwash process involves the consumer's hands being in contact with the detergent product and resulting wash liquor, and the formulation can be harsh on the skin.

[0008] WO 2020 / 016097 discloses the use of rhamnolipid surfactants in a surfactant system for handwash detergents to confer to the consumer a sensorial impression of mildness on the hands.

[0009] Consumers are sensitive to visual cues when using a cleaning product like for example a hand dish wash product. One of the more prominent visual cues is foam formation when cleaning as the amount of foam is seen as an indicator of cleaning performance. More foam is interpretated as more cleaning power. In addition to such ‘in-use’ visual cues, consumers are also sensitive to product appearance. Some consumers prefer clear and transparent product formulations. Inclusion of certain ingredients like e.g. cleaning polymers like polyethylene glycol may challenge formulators to provide transparent product formulations. Either in the immediate end product or over time, e.g. upon storage, when product appearance may change and a clear and transparent product may for example develop sediment and / or become cloudy. The same may happen as a result of temperature changes.

[0010] Nowadays, some consumers prefer cleaning products with a good environmental profile. That is, they prefer products that are ‘eco-friendly’ and have less or no impact on the environment when the product is used but also when the product is manufactured. There are many cleaning products on the market that claim to be ‘eco-friendly’ or ‘natural’, but it is not always easy for consumers to understand what those positive terms really stand for. In addition, some consumers still associate ‘eco-friendly’ cleaning products with less efficacious cleaning products.

[0011] To address these developing consumer preferences, inclusion of biosurfactants can be considered and / or use of certain surfactants can be reduced or avoided altogether, like e.g. sulphonated surfactants like alkylbenzene sulphonates. Another way of addressing these consumer preferences is by lowering the total amount of surfactant in a product. However, these changes may require other ingredients to maintain cleaning efficacy, sometimes referred to as cleaning polymers. One such ingredient is polyethylene oxide.

[0012] Whilst addressing all these formulation requirements, formulators also have to consider the viscosity of the product. Thicker compositions are sometimes preferred by users as these may be easier to dose. For compositions with lower amounts of surfactant, a thick product may also validate appropriate cleaning power perception with users of such compositions. The viscosity of a product is usually modified by adding electrolytes like e.g. inorganic salts to thicken the composition and / or hydroptropes to lower viscosity. This can be a laborious task as it is not always evident upfront how to realize a desired viscosity. Also, higher amounts of inorganic salts may have to be used to achieve a certain viscosity which may not be desirable, e.g. because of environmental or cost considerations.

[0013] In view of the above, there remains a need for aqueous liquid detergent compositions comprising rhamnolipid surfactant without compromising consumer satisfaction in terms of environmental profile and / or product appearance that are easier to formulate. Summary of the Invention

[0014] We have found that aqueous liquid detergent compositions comprising rhamnolipid biosurfactant and a cleaning polymer comprising a specific surfactant system provide for detergent compositions that are transparent and easier to formulate.

[0015] Accordingly, in a first aspect the invention relates to an aqueous liquid detergent composition comprising: from 4 to 8 wt% of a surfactant system comprising:

[0016] (i) a primary surfactant mix comprising alkyl ether sulfate surfactant, alkyl sulfate surfactant and a rhamnolipid biosurfactant; and

[0017] (ii) a secondary surfactant mix comprising an amphoteric surfactant selected from betaines, glucamides and sultaines; from 0.001 to 0.2 wt% of polyethylene oxide having a molecular weight higher than 200,000 g / mol; and an inorganic salt selected from sodium chloride, magnesium sulphate and sodium sulphate; wherein

[0018] - the weight ratio of (alkyl ether sulfate surfactant + alkyl sulfate surfactant + rhamnolipid biosurfactant) I amphoteric surfactant is from 1 to 4;

[0019] - the percentage of secondary surfactant mix calculated on total amount of surfactant system including secondary surfactant is from 2 0 to 30; and the average EO of alkyl ether sulfate surfactant and alkyl sulfate surfactant combined is from 0.45 to 1.

[0020] Preferably the composition is an aqueous liquid hand dishwash detergent composition.

[0021] The invention further relates to a method of cleaning a hard surface using the composition of the invention.

[0022] Detailed Description of the Invention

[0023] 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. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description 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 feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as “wt%”. The use of any and all examples or exemplary language e.g. “such as” provided herein is intended merely to better illuminate the invention and does not in any way limit the scope of the invention otherwise claimed. Room temperature is defined as a temperature of about 20° Celsius.

[0024] The composition of the present invention is an aqueous cleaning composition, that is to say, the composition comprises water. The amount of water will depend on the desired concentration of the other ingredients. Preferably the composition comprises 70 to 96 wt% water, more preferably not less than 65 wt%, still more preferably not less than 70 wt% but typically not more than 96 wt%, more preferably not more than 95 wt%, still more preferably not more than 90 wt%.

[0025] The composition is liquid, that is, it can be poured. Compositions of the present invention preferably have a viscosity in the range of 500 to 3500 cps at 21 sec1measured on a Haake Viscometer (Models include VT181, VT501 , VT550 or equivalent) with “cup” and “bob” geometry, equipped with a MV cup and a MV2 bob at a controlled temperature of 25°C. Preferably 1500 to 2500, like for example 1600 to 2400 and more preferably 1700 to 2300. Thicker compositions are sometimes preferred by users as these may be easier to dose. For compositions with lower amounts of surfactant, a thick product may also validate appropriate cleaning power perception with users of such compositions.

[0026] Viscosity formulation indicator (Fv)

[0027] The composition of the present invention is surprisingly convenient to adjust to the required viscosity and will also require only a limited amount of inorganic salts, like e.g. Na2SC>4, to do so, thereby providing both convenience to the formulator and a more responsible composition due to the lower amount of inorganic salt required.

[0028] This ease of formulation can be expressed in a parameter by looking at the required amount of Na2SC>4 that is needed to get a viscosity of 2500 mPas for a given composition that does not contain viscosity modifiers including electrolytes like e.g. inorganic salts, hydroptropes and viscosity modifying polymers. Using this information, a ‘viscosity formulation indicator’ (Fv) can be calculated as follows:

[0029] Fv= 104* (wt% Na2SC>4 / Target viscosity in mPas)

[0030] Wherein the target viscosity is set at 2500 mPas.

[0031] For example, a composition that requires 2 wt% Na2SC>4 to reach a viscosity of 2500 mPas has a Fvof 104* (2 / 2500) = 8.

[0032] We have found that the Fvgives a good indication of the ease of formulating towards a desired viscosity for the formulator. This means that even if the desired viscosity is for example 2000 mPas, the Fvis still a useful indicator.

[0033] When determining the Fvfor a given composition, and the composition contains viscosity modifiers, the Fvshould be determined for the composition without the inclusion of the viscosity modifiers.

[0034] Preferably compositions of the present invention have a Fv from 0.4 to 12 more preferably from 1 to 12 and even more preferably from 2 to 10.

[0035] Surfactant System

[0036] The composition of the present invention comprises a surfactant system. The surfactant system comprises at least a primary surfactant mix comprising alkyl ether sulfate surfactant, alkyl sulfate surfactant and rhamnolipid biosurfactant; and a secondary surfactant mix comprising amphoteric surfactant.

[0037] The surfactant system is present in the composition in a concentration of 4 to 8 wt%. Preferably the weight ratio of the surfactant system is 4 to 7 wt% and more preferably 5 to 7 wt%.

[0038] Primary surfactant mix

[0039] The surfactant system comprises a primary surfactant mix comprising alkyl ether sulfate surfactant, alkyl sulfate surfactant and rhamnolipid biosurfactant.

[0040] Preferred alkyl ether sulfate surfactants are ones of the formula (Formula I):

[0041] (Ri-(0R’)n-0-S03')xMx+, wherein: Ri is saturated or unsaturated C8-C16, preferably C12-C14 alkyl chain; preferably, Ri is a saturated C8-C16, more preferably a saturated C12-C14 alkyl chain;

[0042] R’ is ethylene; n is from 1 to 15, preferably from 1 to 10, more preferably from 1 to 5, even more preferably from 1 to 3; x is equal to 1 or 2;

[0043] Mx+is a suitable cation which provides charge neutrality, preferably sodium, calcium, potassium, or magnesium, more preferably a sodium cation.

[0044] Preferably, the alkyl ether sulfate surfactant comprises alkyl ether sulfate having 1 to 3 ethylene oxide units per molecule, more preferably 1 to 2 ethylene oxide units per molecule. Preferably the alkyl ether sulfate surfactant comprises lauryl ether sulfate having 1 to 2 ethylene oxide units per molecule.

[0045] The primary surfactant further comprises alkyl sulfate surfactant. Preferably according to the formula (Formula II):

[0046] (RI-O-SC>3')XMX+, wherein:

[0047] Ri is saturated or unsaturated C8-C16, preferably C12-C14 alkyl chain; preferably, Ri is a saturated C8-C16, more preferably a saturated C12-C14 alkyl chain; x is equal to 1 or 2;

[0048] Mx+is a suitable cation which provides charge neutrality, preferably sodium, calcium, potassium, or magnesium, more preferably a sodium cation.

[0049] Examples of alkyl sulfate surfactant include sodium lauryl sulphate. Suitable examples include alkyl sulphates from synthetic origin with trade names Safol 23, Dobanol 23A or 23S, Lial 123 S, Alfol 1412S, Empicol LC3, Empicol 075SR. Further suitable examples, and preferred, include alkyl sulphates commercially available from natural sources with trade names Galaxy 689, Galaxy 780, Galaxy 789, Galaxy 799 SP. Preferably the weight ratio of (alkyl ether sulfate surfactant I alkyl sulfate surfactant) is from 0.2 to 1.

[0050] The composition of the present invention will thus comprise a primary surfactant mix comprising both an alkyl ether sulfate surfactant and alkyl sulfate surfactant.

[0051] In alkyl ether sulfate surfactants, EO refers to the degree of ethoxylation and is usually expressed as ‘n’, with ‘n’ indicating the number of ethylene oxide units per molecule (i.e. the number of EO units). When alkyl ether sulfate surfactants are manufactured this will usually result in a mixture of molecules with a certain distribution of the number of EO units. The average EO of such a mixture can be calculated as follows.

[0052] The average EO is defined as the weighted mean of the percentages of each EO adduct, with EO number comprised between 0 and 15 (i.e. n=0 and i=15), present in the alkyl ether sulfate surfactant and alkyl sulfate surfactant.

[0053] Where Xnm is the % of the nthethoxylation adduct into anionic surfactant m, where m may be either alkyl ether sulfate surfactant or alkyl sulfate surfactant and EOn is the ethoxylation degree of the nthethoxylation adduct.

[0054] For the purpose of the invention the ‘average EO of alkyl ether sulfate surfactant and alkyl sulfate surfactant combined’ means that alkyl sulfate surfactant is understood as the nonethoxylated equivalent of alkyl ether sulfate surfactant wherein n=0. Thus, the average EO considers the amount of both alkyl ether sulfate surfactant and alkyl sulfate surfactant. The calculation of the average EO corresponds to the calculation method explained above.

[0055] The average EO of alkyl ether sulfate surfactant and alkyl sulfate surfactant combined is from 0.45 to 1.

[0056] Rhamnolipid biosurfactant

[0057] The primary surfactant mix further comprises rhamnolipid biosurfactant. Preferably the surfactant system comprises from 0.25 to 5 wt% rhamnolipid biosurfactant, preferably from 0.25 to 3 wt% and more preferably from 0.5 to 2 wt% rhamnolipid biosurfactant. Rhamnolipid biosurfactants are a class of glycolipid. They are constructed of rhamnose combined with beta-hydroxy fatty acids. Rhamnose is a sugar. Fatty acids are ubiquitous in animals and plants.

[0058] Rhamnolipids are discussed in Applied Microbiology and Biotechnology (2010) 86:1323-1336 by E. Deziel et al. Rhamnolipids are produced by Evonik, Stepan, Glycosurf, AGAE Technologies and Urumqi Unite Bio-Technology Co., Ltd. Rhamnolipids may be produced by strains of the bacteria Pseudomonas Aeruginosa. There are two major groups of rhamnolipids; mono-rhamnolipids and di-rhamnolipids.

[0059] Mono-rhamnolipids have a single rhamnose sugar ring. A typical mono-rhamnolipid produced by P. aeruginosa is L-rhamnosyl-p-hydroxydecanoyl-p-hydroxydecanoate (RhaCwC ). It may be referred to as Rha-Cio-C , with a formula of C26H48O9. Mono-rhamnolipids have a single rhamnose sugar ring.

[0060] The IUPAC Name is 3-[3-[(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2- yl]oxydecanoyloxy]decanoic acid.

[0061] Di-rhamnolipids have two rhamnose sugar rings. A typical di-rhamnolipid is L-rhamnosyl-L- rhamnosyl-p-hydroxydecanoyl-p-hydroxydecanoate (Rha2C Cio). It may be referred to as Rha-Rha-C-w-C-10, with a formula of C32H58O13.

[0062] The IUPAC name is 3-[3-[4,5-dihydroxy-6-methyl-3-(3,4, 5-tri hydroxy-6-methyloxan-2- yl)oxyoxan-2-yl]oxydecanoyloxy]decanoic acid.

[0063] In practice a variety of other minor components with different alkyl chain length combinations, depending upon carbon source and bacterial strain, exist in combination with the above more common rhamnolipids. The ratio of mono-rhamnolipid and di-rhamnolipid may be controlled by the production method. Some bacteria only produce mono-rhamnolipid, see US5767090: Example 1, some enzymes can convert mono-rhamnolipid to di-rhamnolipid.

[0064] In various publications mono-rhamnolipids have the notation Rha-, which may be abbreviated as Rh or RL2. Similarly, di-rhamnolipids have the notation Rha-Rha or Rh-Rh- or RL1. For historical reasons "rhamnolipid 2" is a mono-rhamnolipid and "rhamnolipid 1 " is a di- rhamnolipid. This leads to some ambiguity in the usage or "RL1 " and "RL2" in the literature. Throughout this patent specification, we use the terms mono- and di-rhamnolipid in order to avoid this possible confusion. However, if abbreviations are used R1 is mono-rhamnolipid and R2 is di-rhamnolipid. For more information on the confusion of terminology in the prior art see the introduction to US 4814272.

[0065] The following rhamnolipids have been detected as produced by the following bacteria: (C12: 1 , C14:1 indicates fatty acyl chains with double bonds).

[0066] Rhamnolipids produced by P. aeruginosa (mono-rhamnolipids):

[0067] Rha-C8-C10, Rha-C10-C8, Rha-C-10-C10, Rha-C10-C12, Rha-C10-C12:1 , Rha-C12-C10, Rha-C12:1-C10

[0068] Rhamnolipids produced by P. aeruginosa (di-rhamnolipids):

[0069] Rha-Rha-C8-C10, Rha-Rha-C8-C12:1 , Rha-Rha-C10-C8, Rha-Rha-C10-C10, Rha-Rha-C10- C12:1 , Rha- Rha-C-10-C-12, Rha-Rha-C-12-C-10, Rha-Rha-C-12:1-C-12, Rha-Rha-C-10- C14:1.

[0070] Rhamnolipids produced by P. aeruginosa (unidentified as either mono- or di-rhamnolipids): C8-C8, C8-C10, C10-C8, C8-C12:1 , C12:1-C8, C10-C10, C12-C10, C12:1-C10 C12-C12, C12:1-C12, C14-C10, C14:1-C10, C14-C14.

[0071] Rhamnolipids produced by P. chlororaphis (mono-rhamnolipids only):

[0072] Rha-C10-C8, Rha-C10-C10, Rha-C12-C10, Rha-C12:1-C10, Rha-C12-C12, Rha-C12:1-C12, Rha-C14-C10. Rha-C-14:1- C-10.

[0073] Rhamnolipids produced by Burkholdera pseudomallei (di-rhamnolipids only): Rha-Rha-C14-C14.

[0074] Rhamnolipids produced by Burkholdera (Pseudomonas) plantarii (di-rhamnolipids only): Rha-Rha-C14-C14.

[0075] There are over 100 strains of P. aeruginosa on file at the American Type Culture Collection (ATCC). There are also a number of strains that are only available to manufacturers of commercial Rhamnolipids. Additionally, there are probably thousands of strains isolated by various research institutions around the world. Some work has gone into typing them into groups. Each strain has different characteristics including how much rhamnolipid is produced, which types of rhamnolipids are produced, what it metabolizes, and conditions in which it grows. Only a small percentage of the strains have been extensively studied.

[0076] Through evaluation and selection, strains of P. aeruginosa can be isolated to produce rhamnolipids at higher concentrations and more efficiently. Strains can also be selected to produce less byproduct and to metabolize different feedstock or pollutants. This production is greatly affected by the environment in which the bacterium is grown.

[0077] A typical di-rhamnolipid is L-rhamnosyl-L-rhamnosyl-p-hydroxydecanoyl-p-hydroxydecanoate (Rha2CioC with a formula of C32H58O13).

[0078] In practice a variety of other minor components with different alkyl chain length combinations, depending upon carbon source and bacterial strain, exist in combination with the above more common rhamnolipids. The ratio of mono-rhamnolipid and di-rhamnolipid may be controlled by the production method. Some bacteria only produce mono-rhamnolipid, see US5767090: Example 1, some enzymes can convert mono-rhamnolipid to di-rhamnolipid.

[0079] Preferably the rhamnolipid is selected from:

[0080] Rhamnolipids produced by P. aeruginosa (mono-rhamnolipids):

[0081] Rha-C8-C10, Rha-C10-C8, Rha-C10-C10, Rha-C10-C12, Rha-C10-C12:1, Rha-C12-C10, Rha- C12:1-C10

[0082] Rhamnolipids produced by P. chlororaphis (mono-rhamnolipids only):

[0083] Rha-C10-C8, Rha-C10-C10, Rha-C12-C10, Rha-C12:1-C10, Rha-C12-C12, Rha-C12:1-C12, Rha-C14-C10, Rha-C14:1-C10.

[0084] Mono-rhamnolipids may also be produced from P.putida by introduction of genes rhIA and rhIB from Psuedomonas aeruginosa [Cha et al. in Bioresour Technol. 2008. 99(7):2192-9] Rhamnolipids produced by P. aeruginosa (di-rhamnolipids):

[0085] Rha-Rha-C8-C10, Rha-Rha-C8-C12:1 , Rha-Rha-C10-C8, Rha-Rha-C10-C10, Rha-Rha-C10- C12:1 , Rha-Rha-C10-C12, Rha-Rha-C12-C10, Rha-Rha-C12:1-C12, Rha-Rha-C10-C14:1

[0086] Rhamnolipids produced by Burkholdera pseudomallei (di-rhamnolipids only): Rha-Rha-C14-C14.

[0087] Rhamnolipids produced by Burkholdera (Pseudomonas) plantarii (di-rhamnolipids only): Rha-Rha-C14-C14.

[0088] Rhamnolipids produced by P. aeruginosa which are initially unidentified as either mono- or di-rhamnolipids: C8-C8, C8-C10, C10-C8, C8-C12:1, C12:1-C8, C10-C10, C12-C10, C12:1-C10, C12-C12, C12:1-C12, C14-C10, C14:1-C10, C14-C14.

[0089] Most preferably the Rhamnolipid is L-rhamnosyl-p-hydroxydecanoyl-p-hydroxydecanoate (RhaC Cio with a formula of C26H48O9) produced by P. aeruginosa.

[0090] Preferably, the rhamnolipid comprises at least 50 wt.% mono-rhamnolipid, more preferably at least 60 wt.% mono-rhamnolipid, even more preferably 70 wt.% mono-rhamnolipid, most preferably at least 80 wt.% mono-rhamnolipid; alternatively, wherein the rhamnolipid comprises at least 50 wt.% di-rhamnolipid, more preferably at least 60 wt.% di-rhamnolipid, even more preferably 70 wt.% di-rhamnolipid, most preferably at least 80 wt.% di-rhamnolipid.

[0091] Preferably the rhamnolipid is a di-rhamnolipid of formula: Rha2C8-i2Cs-i2. The preferred alkyl chain length is from Cs to C12. The alkyl chain may be saturated or unsaturated.

[0092] The percentage of primary surfactant mix calculated on total amount of surfactant system including primary surfactant may be from 70 to 80.

[0093] Secondary surfactant mix

[0094] The surfactant system comprises a secondary surfactant mix comprising amphoteric surfactant selected from betaines, glucamides and sultaines, wherein the percentage of secondary surfactant mix calculated on total amount of surfactant system including secondary surfactant is from 20 to 30 wt%.

[0095] Preferably the secondary surfactant mix comprises at least 70 wt%, calculated on total amount of secondary surfactant mix, of amphoteric surfactant. More preferably at least 80 wt%, even more preferably at least 90 wt% and still more preferably at least 95 wt%. It may be preferred that the secondary surfactant mix consists of betaine.

[0096] Preferably the amphoteric surfactant comprises at least 70 wt%, calculated on total amount of amphoteric surfactant, of betaine. More preferably at least 80 wt%, even more preferably at least 90 wt% and still more preferably at least 95 wt%. It may be preferred that the amphoteric surfactant consists of betaine. Betaine

[0097] Preferably the amphoteric surfactant comprises betaine. Suitable betaines include alkyl betaine, alkyl amido betaine, alkyl amidopropyl betaine, alkyl sulphobetaine and alkyl phosphobetaine, wherein the alkyl groups preferably have from 8 to 19 carbon atoms.

[0098] Examples include cocodimethyl sulphopropyl betaine, cetyl betaine, laurylamidopropyl betaine, caprylate / caprate betaine, capryl / capramidopropyl betaine, cocam idopropyl hydroxysultaine, cocobutyramido hydroxysultaine, and preferably lauryl betaine, cocam idopropyl betaine and sodium cocamphopropionate. Preferably the betaine is cocam idopropyl betaine (CAPB).

[0099] The weight ratio of (alkyl ether sulfate surfactant + alkyl sulfate surfactant + rhamnolipid biosurfactant) I amphoteric surfactant is from 1 to 4, preferably 2 to 4.

[0100] Further surfactants

[0101] The surfactant system of the present invention may comprise other surfactants in addition to the primary surfactant and secondary surfactant mixes, like for example other anionic surfactants. The surfactant system may also comprise cationic and / or non-ionic surfactant.

[0102] Suitable non-ionic surfactants include the condensation products of a higher alcohol (e.g. an alkanol containing about 8 to 18 carbon atoms in a straight or branched chain configuration) condensed with about 5 to 30 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 16 moles of ethylene oxide (EO), tridecanol condensed with about 6 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol. Particularly preferred is Lauryl alcohol condensed with 5, 7 and 9 moles of ethylene oxide (Laureth 5, Laureth 7 and Laureth 9). Preferably, the non-ionic surfactant is selected from Laureth 5, Laureth 7 and Laureth 9, or mixtures thereof.

[0103] Condensates of 2 to 30 moles of ethylene oxide with sorbitan mono- and tri-C10-C20 alkanoic acid esters having a H LB of 8 to 15 also may be employed as the nonionic surfactant. These surfactants are well known and are available from Imperial Chemical Industries under the Tween trade name. Suitable surfactants include polyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (4) sorbitan monostearate, polyoxyethylene (20) sorbitan trioleate and polyoxyethylene (20) sorbitan tristearate.

[0104] Another nonionic surfactant that may be employed are alkyl polyglycosides. These may be preferred as these have because of their environmentally friendly profile.

[0105] When present, the non-ionic surfactant is in a concentration of 0.1 to 5 % by weight, preferably at least 0.3%, still more preferably at least 0.5% but preferably not more than 4%, more preferably not more than 3%, even more preferably not more than 2% by weight of the surfactant system.

[0106] Some surfactants are known to have other functions as well and are sometimes classified as such although it is commonly known that such ingredients are also surfactants. For example, benzalkonium chloride (BKC) is a known cationic surfactant that can also be employed as an antimicrobial agent. For the purpose of the present invention such ingredients are taken into account for the calculation of weight percentages of surfactant.

[0107] Alkylbenzene sulphonate (ABS) is an anionic surfactant that is not readily available from renewable carbon or biorenewable carbon sources and some consumers may prefer compositions that only have a limited amount of such surfactant or are entirely free thereof.

[0108] Therefore, the surfactant system optionally comprises alkylbenzene sulphonates or derivatives thereof wherein the amount of alkylbenzene sulphonate or derivatives thereof is up to 35 wt% of the anionic surfactant calculated on total amount of anionic surfactant. Preferably up to 20 wt%, more preferably up to 15 wt%, and even more preferably up to 10 wt%.

[0109] Preferably the surfactant system of the present composition is free of alkylbenzene sulphonates and derivatives thereof.

[0110] Alkylbenzene sulphonates (ABS) and derivatives thereof include water-soluble alkali metal salts of organic sulphonates having alkyl radicals typically containing from about 8 to about 22 carbon atoms, preferably 8 to 18 carbon atoms, still more preferably 12 to 15 carbon atoms and may be saturated or unsaturated. Examples include sodium salt of linear alkylbenzene sulphonate, alkyl toluene sulphonate, alkyl xylene sulphonate, alkyl phenol sulphonate, alkyl naphthalene-sulphonate, ammonium diamylnaphthalene-sulphonate and sodium dinonylnaphthalene-sulphonate and mixtures with olefin sulphonates.

[0111] More preferably the surfactant system of the composition of the present invention is free of any sulphonated surfactant.

[0112] Polyethylene oxide

[0113] The liquid detergent composition of the present invention comprises polyethylene oxide having a molecular weight higher than 200,000 g / mol. The polyethylene oxide may be present as a single compound or a mixture of at least two polyethylene oxides having a molecular weight higher than 200,000 g / mol.

[0114] As used herein, ‘polyethylene oxide’ refers to polyethylene oxides (PEO) or high molecular weight polyethylene glycols (PEGs). As used herein, ‘high molecular weight polyethylene glycol’ means a linear homopolymer derived from ethylene oxide and having a molecular weight of at least 200,000 g / mol.

[0115] Preferably, the polyethylene oxide has a molecular weight of 300,000 g / mol to 4,000,000 g / mol, more preferably 500,000 g / mol to 3,000,000 g / mol, even more preferably 1,000,000 to 2,000,000 g / mol.

[0116] Suitable examples include, but are not limited to, polyethylene oxides commercially available with trade names WSR N-10, WSR N-80, WSR N-750, WSR 205, WSR 1105, WSR N-12K, WSR N-60K, WSR-301, WSR-303, WSR-308, all from The Dow Chemical

[0117] Company; polyethylene oxide (PEO) from MSE, Beantown chemicals or Acros Organics; PEO 100K from Polysciences; PEO-1, PEO2, PEO-3, PEO-4, PEO-8, PEO15, PEO-18, PEO-57, PEO-29 from Sumitomo Seika Chemicals Ltd.; or ALKOX polyethylene Glycol from Meisei Chemical Works.

[0118] The polyethylene oxde is present in an amount of 0.001 to 0.2 wt% based on the total weight of the composition. More preferably, the polyethylene oxide is present in an amount of 0.01 to 0.15, even more preferably 0.02 to 0.1 wt%. ic salts

[0119] Preferably the composition comprises 0.05 to 3 wt% of an inorganic salt selected from the group consisting of sodium chloride, magnesium sulfate, sodium sulfate and combinations thereof. Preferably the inorganic salt is sodium sulfate. Inorganic salts advantageously control the viscosity of the detergent compositions.

[0120] Preferably, the composition comprises 0.2 to 3 wt%, more preferably 0.3 to 2.5 wt%, even more preferably 0.5 to 2.0 wt% of an inorganic salt.

[0121] Surprisingly, compositions of the present invention require only limited amounts of inorganic salts to achieve viscosities as desired.

[0122] Preferably the pH of the composition of the present invention is between 3.0 and 8.0 measured at 20° Celsius. Preferably, the pH is between 3.5 and 7.5, more preferably between 4.2 and 4.8.

[0123] The composition according to the invention may contain other ingredients which aid in the cleaning or sensory performance. Compositions according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as colorants, preservatives, fatty acids, anti-microbial agents, perfumes, pH adjusters, sequestrants and alkalinity agents.

[0124] Organic solvents

[0125] Preferred compositions do not contain large amounts of organic solvents, usually added to boost cleaning performance, that is from 0 to 1 wt% organic solvent. Preferably the composition is free of organic solvents.

[0126] Silicones

[0127] Compositions of the present invention preferably comprise only limited amounts of silicones as these may not provide the required user characteristics for cleaning compositions of the present invention. Silicones may for example leave a ‘slippery’ feel to hard surfaces like plates and cutlery. Therefore, the composition of the present invention comprises from 0 to 1 wt%, more preferably from 0 to 0.5 wt% and still more preferably from 0 to 0.1 wt% silicones. Still more preferably the composition is free of silicones.

[0128] Product format

[0129] The composition may be used neat or diluted. For hard surface cleaning or more specifically for dishwashing purposes, the composition is typically applied neat directly to the surface or on an implement like for example a sponge or cloth. When applied in a diluted form, the composition is preferably diluted with water in a ratio of between 1 :1 to 1:100 and more preferably in a ratio of between 1 : 1 to 1 : 10.

[0130] The composition may be packaged in the form of any commercially available bottle or pouch for storing the liquid.

[0131] The bottle or pouch containing the liquid can be of different sizes and shapes to accommodate different volumes of the liquid; preferably between 0.25 and 2 L, more preferably between 0.25 and 1.5 L or even between 0.25 and 1 L. The bottle or pouch is preferably provided with a dispenser, which enables the consumer an easier mode of dispersion of the liquid. Spray or pump-dispensers may also be used.

[0132] Process

[0133] The invention also relates to a method of cleaning a hard surface comprising the steps of: a. contacting the hard surface, optionally in diluted form, with the liquid detergent composition according to the present invention, and b. removing the detergent composition from the hard surface, optionally by rinsing with water.

[0134] Preferably, the method of cleaning is a manual cleaning, more preferably hand dishwashing.

[0135] ‘Hard surface’, as used herein, typically means utensils or kitchenware, kitchen worktops, kitchen floors, sinks and kitchen counter tops, floors and bathrooms.

[0136] In any of the processes above, the composition of the invention is applied onto a hard surface in neat or diluted form. The composition may be applied by any known ways such as by using a cleaning implement, such as scrub, sponge paper, cloth, wipes or any other direct or indirect application. The applied composition may be cleaned using a cleaning implement such as a scrub, sponge, paper, cloth or wipes with or without water, or rinsed off with water, optionally running water.

[0137] The invention will now be illustrated by means of the following non-limiting examples. Examples

[0138] Example 1

[0139] Aqueous liquid detergent compositions were prepared according to Tables 1A and 1 B -

[0140] Samples 1 to 3 and comparatives A to I. The compositions had a pH of about 4.5 adjusted with NaOH and citric acid.

[0141] TABLE 1A (wt% calculated in total product, water to 100)

[0142] 1PEG 45-M. Mw: 2,000,000 g / mol (DOW, Sigma)

[0143] TABLE 1 B (wt% calculated in total product, water to 100)

[0144] For each of the prepared compositions transparency of the formulation was assessed visually and the wt% of Na2SC>4 needed to bring the viscosity to 2500 mPas was determined. If a viscosity of 2500 mPas could be achieved with not more than 3 wt% Na2SC>4 this was recorded as ‘Y’. If more than 3 wt% Na2SC>4 was needed to achieve a viscosity of 2500 mPas or if the viscosity of 2500 mPas could not be realized then this was recorded as ‘N’. The results are given in Table 2.

[0145] TABLE 2

[0146] 2protocol as defined above

Claims

Claims1 . An aqueous liquid detergent composition comprising: from 4 to 8 wt% of a surfactant system comprising:(i) a primary surfactant mix comprising alkyl ether sulfate surfactant, alkyl sulfate surfactant and a rhamnolipid biosurfactant; and(ii) a secondary surfactant mix comprising an amphoteric surfactant selected from betaines, glucamides and sultaines; from 0.001 to 0.2 wt% of polyethylene oxide having a molecular weight higher than 200,000 g / ml; and an inorganic salt selected from sodium chloride, magnesium sulphate and sodium sulphate; wherein the weight ratio of (alkyl ether sulfate surfactant + alkyl sulfate surfactant + rhamnolipid biosurfactant) I amphoteric surfactant is from 1 to 4; the percentage of secondary surfactant mix calculated on total amount of surfactant system including secondary surfactant is from 20 to 30; and the average EO of alkyl ether sulfate surfactant and alkyl sulfate surfactant combined is from 0.45 to 1.

2. The composition according to claim 1 wherein the weight ratio of (alkyl ether sulfate surfactant I alkyl sulfate surfactant) is from 0.2 to 1.

3. The composition according to claim 1 or 2 having a viscosity formulation indicator, Fv, from 0.4 to 12, wherein Fvis calculated as Fv= 104* (wt% NaCI I Target viscosity in mPas), wherein the target viscosity is 2500 mPas and the viscosity is measured on a Haake Viscometer with a cup and bob geometry, equipped with a MV cup and a MV2 bob at a controlled temperature of 25° Celsius.

4. The composition according to any one of claims 1 to 3 comprising from 0.25 to 5 wt% rhamnolipid biosurfactant, preferably from 0.5 to 2 wt%.

5. The composition according to any one of claims 1 to 4 wherein the percentage of primary surfactant mix calculated on total amount of surfactant system including primary surfactant is from 70 to 80.

6. The composition according to any one of claims 1 to 5 wherein the alkyl ether sulfate surfactant comprises alkyl ether sulfate having 1 to 2 ethylene oxide units per molecule, preferably lauryl ether sulfate having 1 to 2 ethylene oxide units per molecule.

7. The composition according to any one of claims 1 to 6 wherein the amphoteric surfactant comprises betaine selected from alkyl betaine, alkyl amido betaine, alkyl amidopropyl betaine, alkyl sulphobetaine, alkyl phosphobetaine and combinations thereof.

8. The composition according to any one of claims 1 to 7 wherein the betaine is cocam idopropyl betaine.

9. The composition according to any one of claims 1 to 8 wherein the polyethylene oxide has a molecular weight of 500,000 g / mol to 3,000,000 g / mol.

10. The composition according to any one of claims 1 to 9 wherein the composition has a pH in the range of 3 to 8 measured at 20° Celsius.

11. The composition according to any one of claims 1 to 10 wherein the composition has a viscosity in the range of 500 to 3500 cps at 21 sec1measured on a Haake Viscometer with a cup and bob geometry, equipped with a MV cup and a MV2 bob at a controlled temperature of 25° Celsius, preferably 1500 to 2500 and more preferably 1700 to 2300.

12. The composition according to any one of claims 1 to 11 wherein the composition comprises from 0 to 1 wt% silicone.

13. The composition according to any one of claims 1 to 12 wherein the surfactant system comprises alkylbenzene sulphonate or derivatives thereof in an amount of up to 25 wt% of the total amount of anionic surfactant and preferably is free of any sulphonate.

14. A method of cleaning a hard surface comprising the steps: contacting the hard surface, optionally in diluted form, with the liquid detergent composition according to any one of claims 1 to 13, and removing the detergent composition from the hard surface, optionally by rinsing with water.

15. The method of cleaning according to claim 14, wherein the hard surface is dishware.

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