Field of the invention

The present invention relates to hard surface cleaning compositions, in particular liquid aqueous detergent compositions comprising a surfactant system with a high Renewable Carbon Index (RCI) with good emulsification and oily soil removal of hard surfaces, such as tableware.

Background of the invention

Household cleaning activities involve the use of a detergent product and 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 excellent detergency and soil removal capacity.

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.

The Renewable Carbon Index (RCI) is a way to quantify the ‘eco-friendly’ profile of ingredients and products. The higher the RCI the better the renewable profile of the ingredient or product is. A further refined version of such an index is the Biorenewable Carbon Index (BCI) wherein at least part of the carbon in an ingredient or product is derived from recently living plant or animal organisms.

The surfactant system in cleaning product contributes to the cleaning efficacy in such products. The RCI and BCI of surfactants may widely vary with some having a high RCI or BCI, like alkyl polyglycosides (APG) and rhamnolipids, because of their very nature, and other surfactants that are simply not available from a renewable source. It may not always be possible to formulate surfactant systems solely with surfactants like APG and rhamnolipids because of supply, cost and/or formulation restraints, and sometimes such surfactant mixes do not match the desired cleaning profile. Some of the most widely used surfactants are not (cost effectively) available as ingredients with a high RCI or BCI, like for example alkylbenzene sulphonates (ABS).

In view of the above, there remains a need for a hard surface cleaning composition with a good environmental profile providing good emulsification and oily soil removal properties without compromising consumer satisfaction in terms of cleaning performance and/or for example foam formation in the main wash.

Summary of the invention

We have found that cleaning compositions comprising a surfactant system comprising anionic surfactant and amphoteric surfactant in certain weight ratios provide good oily soil removal whilst the surfactant system has a high Renewable Carbon Index (RCI).

Accordingly, in a first aspect the invention relates to a liquid aqueous detergent composition comprising, a. 8 to 30 wt% of a surfactant system comprising, i. primary surfactant being anionic surfactant comprising a surfactant of the formula (Ri-(OR’) _n -O-SO3')xM ^x+ , wherein:

Ri is saturated or unsaturated Cs-C alkyl chain;

R’ is ethylene; n is from 1 to 18; x is equal to 1 or 2;

M ^x+ is a suitable cation which provides charge neutrality selected from sodium, calcium, potassium and magnesium; and optionally comprising alkyl sulphate; and ii. secondary surfactant being amphoteric surfactant comprising betaine and amine oxide in a weight ratio of betaine to amine oxide in the range from 1:1 to 7:1 ; b. 0.001 to 0.2 wt% of polyethylene oxide having a molecular weight higher than 200,000 g/mol; c. 0.1 to 5 wt% of an inorganic salt selected from the group consisting of sodium chloride, magnesium sulphate, sodium sulphate and combinations thereof; wherein the surfactant system has a Renewable Carbon Index (RCI) of at least 0.8; and wherein the weight ratio of primary surfactant to secondary surfactant is in the range from 2:1 to 8:1.

The invention further relates to a method of cleaning a hard surface using the composition of the invention, as well as the use thereof.

Detailed description of the invention

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 degrees Celsius.

Surfactant System

The liquid aqueous detergent composition of the present invention comprises a surfactant system. The surfactant system comprises at least primary and secondary surfactant wherein the weight ratio of primary surfactant to secondary surfactant is in the range from 2:1 to 8:1. Preferably the weight ratio is from 4:1 to 7:1 , more preferably 5:1 to 7:1. The surfactant system is present in the composition in a concentration of 8 to 30 wt%. Preferably the weight ratio of the surfactant system is 8 to 25 wt%, more preferably 9 to 20 wt% and even more preferably 9 to 15 wt%.

Primary surfactant

The primary surfactant is an anionic surfactant comprising a surfactant of the formula (Formula I):

(Ri-(OR’) _n -O-SO3')xM ^x+ , wherein:

Ri is saturated or unsaturated Cs-C , preferably C12-C14 alkyl chain; preferably, R1 is a saturated Cs-C , more preferably a saturated C12-C14 alkyl chain;

R’ is ethylene; n is from 1 to 18, preferably from 1 to 15, more preferably from 1 to 10, still more preferably from 1 to 5; x is equal to 1 or 2;

M ^x+ is a suitable cation which provides charge neutrality, preferably sodium, calcium, potassium, or magnesium, more preferably a sodium cation.

Preferably, the primary surfactant comprises sodium lauryl ether sulphate having 1 to 3 ethylene oxide units per molecule, more preferably, sodium lauryl ether sulphate having 1 to 2 ethylene oxide units per molecule.

Preferably the primary surfactant comprises at least 70 wt% calculated on total amount of primary surfactant, more preferably at least 80 wt%, even more preferably at least 90 wt% and still more preferably at least 95 wt% surfactant of Formula I. It may be preferred that the primary surfactant consists of surfactant of Formula I.

The primary surfactant may optionally comprise alkyl sulphates, i.e. primary alcohol sulphates. Examples of alkyl sulphates include sodium lauryl sulphate, ammonium lauryl sulphate and diethanolamine (DEA) 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 when alkyl sulphates are present in the primary surfactant, include alkyl sulphates commercially available from natural sources with trade names Galaxy 689, Galaxy 780, Galaxy 789, Galaxy 799 SP.

The primary surfactant may comprise other anionic surfactants such as rhamnolipids, being anionic biosurfactants.

Primary surfactant may be present in a concentration of 5 to 89 wt%, preferably 10 to 85 wt%, more preferably 15 to 80 wt%, even more preferably 20 to 70 wt% and still even more preferably 25 to 60 wt%, by total weight of the surfactant system.

Secondary surfactant

The secondary surfactant is amphoteric surfactant comprising betaine and amine oxide in a weight ratio of betaine to amine oxide in the range from 1:1 to 7:1. The specific weight ratio allows for improved emulsification in the compositions of the present invention.

Preferably the weight ratio of betaine to amine oxide is in the range from 2:1 to 6:1 , more preferably from 3:1 to 5:1. So for example, a weight ratio of 6:1 means that there is 6 times more betaine present than amine oxide.

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

Secondary surfactant may be present in a concentration of 0.1 to 30 wt%, preferably 0.5 to 25 wt%, more preferably 1 to 20 wt%, even more preferably 2 to 15 wt% and still even more preferably 3 to 10 wt% by total weight of the surfactant system.

Betaine 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.

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

Amine oxide

The amphoteric surfactant comprises an amine oxide surfactant. Preferred amine oxides are alkyl dimethyl amine oxide and alkyl amido propyl dimethyl amine oxide, more preferably alkyl dimethyl amine oxide. Especially preferred are lauryl dimethylamine oxide, coco dimethyl amine oxide and coco amido propyl dimethyl amine oxide.

Further surfactants

The surfactant system of the present invention may comprise other types of surfactants in addition to the anionic surfactant of the primary surfactant and amphoteric surfactant of the secondary surfactant. More specifically the surfactant system may also comprise cationic and/or non-ionic surfactant.

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.

Condensates of 2 to 30 moles of ethylene oxide with sorbitan mono- and tri-C10-C20 alkanoic acid esters having a HLB 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.

Another nonionic surfactant that may be employed are alkyl polyglycosides. These may be preferred as these have a high Renewable Carbon Index (RCI) and Biorenewable Carbon Index (BCI).

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.

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.

Renewable Carbon Index (RCI) and Biorenewable Carbon Index (BCI)

Renewable carbon is defined as carbon derived from recently living plant or animal organisms (as opposed to carbon derived from fossil carbon which is coal, oil or petroleum based), as well as carbon derived from CO2 capture.

Biorenewable carbon is defined as carbon derived from recently living plant or animal organisms and as such has no carbon derived from fossil carbon which is coal, oil or petroleum based.

In the context of the present invention, RCI is defined as the value calculated by dividing the number of renewable carbons by the total number of carbons in the entire molecule, and BCI is defined as the value calculated by dividing the number of biorenewable carbons by the total number of carbons in the entire molecule. For example, if 80% of the number of carbons present in a surfactant system is renewable carbon then the RCI is 0.8.

The liquid detergent composition of the present invention comprises a surfactant system having a RCI of at least 0.8. Preferably a RCI of at least 0.85, more preferably at least 0.9 and even more preferably at least 0.95. Ideally the surfactant system has a RCI of 1.

For liquid detergent compositions that require an ‘eco’ label it will be understood that the surfactant system preferably has a BCI of at least 0.8. Preferably a BCI of at least 0.85, more preferably at least 0.9 and even more preferably at least 0.95. Ideally the surfactant system has a BCI of 1 .

Alkylbenzene sulphonates (ABS)

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 diamylnaphthalenesulphonate and sodium dinonylnaphthalene-sulphonate and mixtures with olefin sulphonates.

ABS is not readily available from renewable carbon or biorenewable carbon sources. Therefore, any amount of ABS in the surfactant system of compositions of the present invention will not contribute to the RCI or BCI of the surfactant system. It is therefore preferred that the amount of ABS in the surfactant system is kept at very low levels like for example from 0 to 5 wt% or 0 to 3 wt% calculated on total surfactant system. Preferably the surfactant system is essentially free of ABS and derivatives thereof wherein essentially free is defined as from 0 to 1 wt% calculated on total surfactant system. Even more preferably the surfactant system is free of ABS. Polyethylene oxide

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.

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.

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.

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 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.

The polyethylene oxide is present in an amount of 0.001 to 0.2 wt.% based on the total weight of the composition. Preferably, the polyethylene oxide is present in an amount of 0.01 to 0.18, more preferably 0.1 to 0.15 wt.%.

Inorganic salts

The liquid detergent composition comprises 0.1 to 5% by weight of an inorganic salt selected from the group consisting of sodium chloride, magnesium sulfate, sodium sulfate and combinations thereof. Inorganic salts advantageously control the viscosity of the detergent compositions.

Preferably, liquid detergent composition comprises 0.5 to 4%, more preferably 1.0 to 3%, even more preferably 1.5 to 2.5 % by weight of an inorganic salt. Water

The composition further comprises water. Preferably 60 to 92%, more preferably not less than 62%, still more preferably not less than 65% but typically not more than 85%, more preferably not more than 80%, still more preferably not more than 75% by weight of the composition.

Optional Ingredients

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 thickeners, colorants, preservatives, fatty acids, anti-microbial agents, perfumes, pH adjusters, sequestrants, alkalinity agents and hydrotropes.

Organic solvents

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.

Silicones

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 the hard surface. Therefore, the composition of the present invention preferably 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. pH of the composition

Preferably the pH of the composition of the present invention is between 4.0 to 8.0. Preferably, the pH is 4.5 and 7.5, preferably between 4.5 and 7.0, more preferably between 5.0 and 6.5.

Viscosity

Preferably the composition of the present invention has a viscosity in the range of 1000 to 2700 cps at 21 sec ¹ measured 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 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.

Organic solvents

Sometimes organic solvents like for example ethers, glycol ethers, ketones, diols, alcohols and combinations thereof are included to liquid aqueous detergent compositions to improve cleaning performance of such compositions. Examples of such organic solvents include low carbon alcohols like ethanol and isopropyl alcohol, alkoxylated aliphatic alcohols like butoxypropanol, and glycol ethers like ethylene glycol n-butyl ether, ethylene glycol propyl ether and dipropylene glycol dimethyl ether.

Some consumers may prefer aqueous detergent compositions that only have a limited amount of such organic solvents as these are sometimes associated with being environmentally unfriendly. Therefore, the liquid aqueous detergent compositions of the present invention preferably comprise 0 to 1 wt% of such organic solvents and more preferably 0 to 0.5 wt%. Even more preferably the liquid aqueous detergent composition is essentially free of organic solvents.

Product format

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.

The composition may be packaged in the form of any commercially available bottle for storing the liquid.

The bottle 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 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.

Process

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.

The method can be performed manually (e.g. cleaning by hand) or in a cleaning device, such as an industrial or at home dishwashing machines. Preferably, the method of cleaning is a manual cleaning, more preferably hand dishwashing.

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

In a further aspect, the invention relates to the use of a liquid detergent composition of the invention for handwashing hard surfaces, preferably dishware.

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.

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

Examples

Detergent compositions A (not according to the invention) and 1 to 4 (according to the invention) were prepared. The pH of the formulations was around pH 6. The formulations are included in Table 1. TABLE 1 , detergent compositions (wt%)

SLES 1 EO: Sodium Lauryl ether sulphate 1 EO (on 100% active basis)

CAPB: Coco Amido Propyl Betaine (On 100% active basis)

Example 1: Emulsification test

The formulations as in Table 1 were evaluated as to their emulsification capacity. 5 g of the formulation was poured into a 250 ml beaker, to which 50 ml of 24 FH. (‘French Hardness’) water at 25°C were added followed by stirring until dissolution. To the homogeneous mixture, 25 g of an oil mix consisting of 95 wt% sunflower oil, 2.5 wt% stearic acid and 2.5 wt% oleic acid was added. The mixture was stirred for 2 min at 1200 RPM and then transferred to a 250 ml glass cylinder.

The non-emulsified phase was measured (in mm) after 30 min from start time (1 ^st reading) and after 90 min from start time (2 ^nd reading).

‘E value’ (‘emulsification value’) was calculated according to the following equation: E value= [(1 ^st Reading+2 ^nd Reading)*60]/2

Lower E values indicate better emulsification and oily soil removal. The results are shown in Table 2.

TABLE 2, Emulsification values