WO2023237299A1

WO2023237299A1 - Liquid aqueous dishwashing detergent compositions

Info

Publication number: WO2023237299A1
Application number: PCT/EP2023/062953
Authority: WO
Inventors: Alexandre François BOUX DE CASSON; Robert John Carswell; Marco Antonio DISTASO; Letitia DOLLAMORE; Sukriti SINGH
Original assignee: Unilever Ip Holdings B.V.; Unilever Global Ip Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2022-06-09
Filing date: 2023-05-15
Publication date: 2023-12-14

Abstract

The present invention relates to a liquid aqueous dishwashing detergent composition comprising, a 1 to 50 wt% of a surfactant system comprising: i primary surfactant being anionic surfactant; and ii optionally secondary surfactant comprising amphoteric surfactant; b one or more enzymes; and c inorganic salt; wherein the composition comprises 0 to 0.5 wt% of enzyme stabilizer, the anionic surfactant comprises alkylbenzene sulphonate, and wherein the amount of alkylbenzene sulphonate is up to 22 wt% of the anionic surfactant calculated on total amount of anionic surfactant. The invention further relates to a method of cleaning a hard surface using the composition of the invention, as well as the use thereof.

Description

Liquid aqueous dishwashing detergent compositions

Field of the Invention

The present invention relates to liquid aqueous dishwashing detergent compositions, in particular liquid aqueous dishwashing detergent compositions comprising enzyme and anionic surfactant comprising alkyl benzene sulphonate, and a method and use comprising the same.

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.

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

Consumers are sensitive to product appeal like for example visual cues when using a cleaning product like a hand dishwash 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. Anionic surfactants are often used to provide an adequate foam profile, like for example alkyl benzene sulphonates. In addition to such ‘in-use’ visual cues, consumers are also sensitive to product appearance. Some consumers prefer clear and transparent product formulations. Over time, e.g. upon storage, 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.

To improve cleaning efficacy of hand dishwash compositions cleaning actives like e.g. cleaning polymers may be added. An example of such a cleaning polymer is PEG 45-M, a polyethylene glycol polymer. 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.

Cleaning actives that by some consumers are recognized as ‘eco-friendly’ include enzymes. Enzymes as cleaning actives are sometimes referred to as detersive enzymes. An example of such an enzyme is amylase that assists with starch removal from dishes and cookware. When including enzymes in dishwashing compositions formulators have to consider the stability of the enzyme in the hand dishwash composition upon storage and upon use. WO 97/36977 (P&G) suggests that it is well known that surfactant can deactivate amylase. Others have suggested that enzyme stability is especially susceptible to the presence of alkyl benzene sulphonate surfactant. To stabilize the enzyme, so-called enzyme stabilisers are often used.

In view of the above, there remains a need for a dishwashing detergent composition with a good environmental profile providing good cleaning performance, like for example effective removal of starch and other soils, without compromising consumer satisfaction in terms of product appeal.

Summary of the Invention

We have found that under certain conditions liquid aqueous dishwashing detergent compositions may comprise both enzymes and alkyl benzene sulphonate anionic surfactant without compromising the stability of the enzyme and without the need of additional enzyme stabilizing actives.

Accordingly, in a first aspect the invention relates to a liquid aqueous dishwashing detergent composition comprising, a 1 to 50 wt% of a surfactant system comprising: i primary surfactant being anionic surfactant; and ii optionally secondary surfactant comprising amphoteric surfactant; b one or more enzymes; and c inorganic salt; wherein the composition comprises 0 to 0.5 wt% of enzyme stabilizer, the anionic surfactant comprises alkylbenzene sulphonate, and wherein the amount of alkylbenzene sulphonate is up to 22 wt% of the anionic surfactant calculated on total amount of anionic surfactant.

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.

Aqueous detergent composition

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 50 to 99 wt% water, more preferably not less than 60 wt%, still more preferably not less than 65 wt% but typically not more than 85 wt%, more preferably not more than 80 wt%, still more preferably not more than 75 wt%.

The composition is liquid, that is, it can be poured. Compositions of the present invention preferably have a viscosity in the range of 1000 to 2700 cps at 21 sec¹ 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.

Surfactant System

The composition of the present invention comprises a surfactant system. The surfactant system comprises at least primary and optionally secondary surfactant wherein the weight ratio of primary surfactant to secondary surfactant preferably is in the range from 4:1 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 1 to 50 wt%. Preferably the amount of surfactant system is 5 to 40 wt%, more preferably 6 to 30 wt% and even more preferably 7 to 20 wt%. Like for example 8 to 25 wt%, 8 to 20 wt% or 8 to 15 wt%.

Primary surfactant

The primary surfactant is an anionic surfactant, wherein the anionic surfactant comprises alkylbenzene sulphonate, and wherein the amount of alkylbenzene sulphonate is up to 22 wt% of the anionic surfactant calculated on total amount of anionic surfactant. It will be understood that the total amount of anionic surfactant includes the amount of alkylbenzene sulphonate. To illustrate, if the primary surfactant comprises 3 wt% alkylbenzene sulphonate and 17 wt% alkyl ether sulphate, so a total amount of anionic surfactant of 20 wt%, the anionic surfactant comprises 15 wt% of alkylbenzene sulphonate calculated on total amount of anionic surfactant.

The presence of some amount of alkylbenzene sulphonate is often desired because of the cleaning ability of such compounds. However, alkylbenzene sulphonate are known to sometimes destabilize enzymes. We have found that if the amount of alkylbenzene sulphonate is limited to up to 22 wt% of the anionic surfactant calculated on total amount of anionic surfactant the stability of the enzyme is not compromised without the need of additional enzyme stabilizing actives.

Preferably the amount of alkylbenzene sulphonate is from 0.5 to 22 wt%, more preferably 1 to 22 wt%, even more preferably 2 to 22 wt%, still even more preferably 3 to 21 wt% and even still more preferably 4 to 20 wt% of the anionic surfactant calculated on total amount of anionic surfactant. For example, the amount of alkylbenzene sulphonate may be 5 to 15 wt% or 6 to 10 wt% of the anionic surfactant calculated on total amount of anionic surfactant.

Alkylbenzene sulphonates (ABS)

Alkylbenzene sulphonates (ABS) 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.

Preferably the composition comprises 0.5 to 12.5 wt%, more preferably 1 to 10 wt% and even more preferably 2 to 8 wt% alkylbenzene sulphonate.

Further anionic surfactants

Preferably the composition comprises 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 alkyl ether sulphate having 1 to 3 ethylene oxide units per molecule, more preferably, sodium alkyl ether sulphate having 1 to 2 ethylene oxide units per molecule. A preferred alkyl moiety is lauryl. 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.

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

If present, the secondary surfactant is amphoteric surfactant, preferably comprising betaine.

Preferably the secondary surfactant comprises at least 70 wt%, calculated on total amount of secondary 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 secondary surfactant consists of betaine.

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, cocam idopropyl betaine and sodium cocamphopropionate. Preferably the betaine is cocam idopropyl betaine (CAPB).

Amine oxide

The amphoteric surfactant may comprise 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 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.

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.

Enzymes

Compositions according to the present invention comprise one or more enzymes which provide cleaning performance benefits. Said enzymes include enzymes selected from cellulases, hemicellulases, peroxidases, proteases, gluco-amylases, amylases, lipases, cutinases, pectinases, xylanases, reductates, oxidases, phenoxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, beta-glucanases, arabinosidases, fatty acid decarboxylase, hydroxyperoxy fatty acid producing enzymes, oleic acid transforming enzyme, diol synthases, xylogluconase, nuclease enzyme, hexosaminidase and mixtures thereof. Preferably the one or more enzymes are selected from amylase, protease, lipase and peroxidase. More preferably the composition comprises one or more enzymes selected from amylase and protease, such as compositions wherein the enzyme comprises amylase and compositions wherein the enzyme comprises protease. Preferred compositions comprise enzymes wherein the enzymes comprise amylase and protease.

An amylase enzyme can digest starch molecules present in soil residues into simpler short chain molecules (e.g., simple sugars) which are, of themselves, more readily desorbed from surfaces, solubilized or otherwise more easily removed by the cleaning solution containing the amylases. An amylase included in compositions of the invention can be derived from a plant, an animal, or a microorganism. In one example, the composition includes an amylase derived from a microorganism, such as a yeast, a mold, or a bacterium. For example, the composition may include an amylase derived from a Bacillus, such as B licheniformis, B. amyloliquefaciens, B. subtilis, or B. stearothermophilus. The amylase can be purified or a component of a microbial extract, and either a wild type or variant (either chemical or recombinant). In some examples, the composition includes an alpha amylase (u-amylase). Examples of amylase enzymes that may be employed in the composition include those sold under the trade names Rapidase by Gist-Brocades® (Netherlands), Termamyl®, Fungamyl®, Duramyl®, Amplify®, Amplify Prime®, Stainzyme® or Stainzyme Plus® by Novozymes, Opitmase® AA, Preferenz®, or Purastar® by DuPont, and the like. A mixture of amylases can also be used.

Proteases can cleave complex, macromolecular protein structures present in soil residues into simpler short chain molecules which are, of themselves, more readily desorbed from surfaces, solubilized or otherwise more easily removed by the detergent composition containing the proteases. Proteases are generally classified into serine proteases, thiol proteases, carboxyl proteases and metal proteases, depending upon their active sites. They may also be classified into three of microorganism-, plant- and animal-derived proteases, depending upon their origins. Microorganism-derived proteases are further classified into bacteria-, actinomycete-, mold- and yeast-derived proteases. Any suitable protease may be included in the detergent composition of the present invention. In different examples, the protease included in the composition can be derived from a plant, an animal, or a microorganism. In one example, the composition includes a protease derived from a microorganism, such as a yeast, a mold, or a bacterium. For example, the composition may include a serine protease, e.g., derived from a strain of Bacillus such as Bacillus subtilis or Bacillus licheniformis. These proteases can include native and recombinant subtilisins. The protease can be purified or a component of a microbial extract, and either a wild IO type or variant (either chemical or recombinant. Examples of commercially available proteases that may be incorporated in compositions of the present invention include those sold under the trade names Alcalase®, Savinase® (e.g., Savinase® 15 Ultra 16L), Primase®, Durazym®, Esperase®, Coronase®, Blaze®, Liquanase®, Progress Uno®, Lavergy Pro®, Maxatase®, Maxacai®, Maxapem®, Opticlean®, Optimase® PR, Effectenz®, Purafect®, and Purafect® OX. Mixtures of different protease enzymes may also be incorporated in the composition. Examples of preferred enzymes are sold under the following trade names Purafect Prime®, Purafect®, Preferenz® (DuPont), Savinase®, Pectawash®, Mannaway®, Lipex ®, Lipoclean ®, Whitzyme ® Stainzyme®, Stainzyme Plus®, Natalase ®, Mannaway ®, Amplify ® Xpect ®, Celluclean ® (Novozymes), Biotouch (AB Enzymes), Lavergy ® (BASF).

Preferably the composition comprises the one or more enzymes in an amount of 0.00001 to 4 wt%, more preferably 0.0001 to 3 wt%, even more preferably 0.0001 to 2 wt%, still more preferably 0.0001 to 1 wt%, and even still more preferably 0.001 to 0.5 wt% enzyme protein, like for example compositions comprising 0.01 to 0.30 wt% of one or more enzymes.

Cleaning polymer

The liquid detergent composition of the present invention comprises a cleaning polymer. Typical examples of cleaning polymers include hydrophobically modified polymers, alkoxylated polyalkyleneimines, polyamines and polyethyleneoxides.

Preferably the cleaning polymer is a 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. Preferably the cleaning polymer is present in an amount of 0.001 to 0.2 wt% based on the total weight of the composition. More preferably in an amount of 0.01 to 0.18, and even more preferably 0.1 to 0.15 wt%.

Inorganic salts

Preferably the composition comprises 0.1 to 5% by weight of an inorganic salt. Preferably the inorganic salt is 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. pH of the composition

Preferably the pH of the composition of the present invention is between 4 to 8. Preferably, the pH is between 4.5 and 7.5, preferably between 4.5 and 7, more preferably between 5 and 6.5 and even more preferably between 6 and 7. Compositions having a neutral pH, like for example between 6.5 and 7.5, are especially preferred.

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.

Preferably the composition is essentially free of enzyme stabilizers. The composition comprises 0 to 0.5 wt% even more preferably 0 to 0.1 wt% of enzyme stabilizer. Preferably the composition is free of enzyme stabilizers.

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.

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 to C (not according to the invention) and 1 to 3 (according to the invention) were prepared. The pH of the formulations was about 7 and the viscosity set to about 2000 mpa.s. The compositions are included in Table 1.

TABLE 1 , Detergent compositions (wt%)

pH was adjusted to pH 7 using sodium hydroxide and citric acid Viscosity was set to about 2000 mpa.s @21 s-1 by addition of sodium chloride

LAS: C10-C13 linear alkyl benzene sulphonate

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

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

Example 1 - amylase stability

The stability of amylase was tested in each of the compositions of Table 1 for 2 amylases: Amplify® Prime 100L (ex Novozymes) and Preferenz® S210 (ex IFF). The enzyme was added at a concentration of 0.27 %w/v. The results are given in Table 2.

The (storage) stability of the enzyme was tested according to the following protocol:

• The compositions were stored in incubators at 37°C for four weeks.

• 30mL of each of the compositions was prepared and 1ml was added in triplicates for fivetime points in the deep well plate giving five blocks for each time point.

• After incubating each time point, each deep well block representing individual time points was stored at -20°C before enzyme activity analysis.

• After four weeks of incubation, amylase activity was assessed by using the Randox amylase kit.

• The enzyme-containing storage samples were diluted using water for assay.

• Samples were run in quadruplicates.

• In the 96 well assay plate, 150pL of Reagent R1 ((4-(2-hydroxyethyl)-1- piperazineethanesulfonic acid) was added, followed by a 20pL diluted amylase sample.

• The kinetic run was started by adding 30pL Reagent R2 (ethylidene blocked-pnpg7).

• The kinetics of the reaction was observed on a Varioskan spectrometer for 15 minutes at 405 nm.

• Absorbance at 5 minutes was used to calculate the residual enzyme activity for each incubation time point. The enzyme activity is calculated by applying the following formula:

TABLE 2, Enzyme stability (% activity at TO)

Claims

1 . A liquid aqueous dishwashing detergent composition comprising, a 1 to 50 wt% of a surfactant system comprising: i primary surfactant being anionic surfactant; and ii optionally secondary surfactant comprising amphoteric surfactant; b one or more enzymes; and c inorganic salt; wherein the composition comprises 0 to 0.5 wt% of enzyme stabilizer, the anionic surfactant comprises alkylbenzene sulphonate, and wherein the amount of alkylbenzene sulphonate is up to 22 wt% of the anionic surfactant calculated on total amount of anionic surfactant.

2. The composition according to claim 1 wherein the amount of alkylbenzene sulphonate is from 0.5 to 22 wt%, preferably 1 to 22 wt%, more preferably 2 to 22 wt%, even more preferably 3 to 21 wt% and still even more preferably 4 to 20 wt% of the anionic surfactant calculated on total amount of anionic surfactant.

3. The composition according to claim 1 or claim 2 wherein the composition comprises 0.5 to 12.5 wt%, preferably 1 to 10 wt% and more preferably 2 to 8 wt% alkylbenzene sulphonate.

4. The composition according to any one of claims 1 to 3 wherein the composition comprises one or more enzymes in an amount of 0.00001 to 4 wt%.

5. The composition according to any one of claims 1 to 4 wherein the surfactant system comprises secondary surfactant.

6. The composition according to any one of claims 1 to 5 wherein the weight ratio of primary surfactant to secondary surfactant is in the range from 4:1 to 8:1.

7. The composition according to any one of claims 1 to 6 wherein the primary surfactant comprises sodium alkyl ether sulphate, preferably having 1 to 2 ethylene oxide units per molecule. The composition according to any one of claims 1 to 7 wherein the secondary surfactant comprises betaine selected from alkyl betaine, alkyl amido betaine, alkyl amidopropyl betaine, alkyl sulphobetaine, alkyl phosphobetaine and combinations thereof. The composition according to any one of claims 1 to 8 wherein the amount of surfactant system is from 5 to 40, preferably 6 to 30 and more preferably from 7 to 20 wt%. The composition according to any one of claims 1 to 9 comprising a cleaning polymer being a polyethylene oxide having a molecular weight higher than 200,000 g/mol, preferably a molecular weight of 500,000 g/mol to 3,000,000 g/mol. The composition according to any one of claims 1 to 10 wherein the composition has a pH in the range of 4 to 8. The composition according to any one of claims 1 to 11 wherein the composition has a viscosity in the range of 1000 to 2700 cps at 21 sec¹ 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. A method of cleaning a hard surface comprising the steps: a contacting the hard surface, optionally in diluted form, with the liquid detergent composition according to any one of claims 1 to 12, and b removing the detergent composition from the hard surface, optionally by rinsing with water. The method of cleaning according to claim 13, wherein the hard surface is dishware. Use of a liquid detergent composition according to any one of claims 1 to 12 for handwashing hard surfaces, preferably dishware.