Aqueous alkaline liquid cleaning composition

Abstract

The present invention relates to aqueous alkaline liquid cleaning compositions comprising sequestrant, surfactant system, hypochlorite salt and water and having a pH of 12 to 14. The invention further relates to a method of removing limescale deposits from a hard surface and the use of sequestrants in such compositions for the same.

Description

[0001] P0000882 CPL

[0002] 1

[0003] AQUEOUS ALKALINE LIQUID CLEANING COMPOSITION

[0004] Field of the Invention

[0005] 5 The present invention relates to hard surface cleaning compositions, in particular aqueous alkaline liquid cleaning compositions comprising sequestrant agent wherein the composition provides limescale removal from hard surfaces.

[0006] Background of the Invention

[0007] Cleaning of inanimate hard surfaces is part of a recurring activity for many people, be it as a consumer in and around the house or as a professional cleaner in e.g. hotels, restaurants and public bathrooms. Such hard surfaces e.g. include floors, toilets, kitchen surfaces like kitchen tops, ovens and refrigerators, and bathroom surfaces like tiles and shower cabin surfaces.

[0008] 15 By cleaning such surfaces the user may desire to remove visible and invisible soil such to achieve a clean look as well as to disinfect such surfaces. Disinfection may be obtained by using surfactants, but often is done by using specific disinfecting agents like bleach.

[0009] A continuing worry for consumers is the presence of limescale deposits on hard surfaces.

[0010] 20 Limescale deposits are perceived to indicate that the surface is not clean and are generally disliked as limescale will negatively impact the aesthetic appeal of such hard surfaces. Such stains are also notoriously difficult to remove. In addition to physical removal by e.g. using an abrasive cleaning formulation, acids or acidic cleaning formulations are often used. Acids of choice may include acetic acid and citric acid that are used as such or in an acidic aqueous

[0011] 25 cleaning composition further comprising surfactant.

[0012] It may not always be desired or possible to use acids or acidic cleaning compositions for limescale removal. Certain materials, like e.g. marble, will be irreversibly damaged as the acid will etch the marble surface. However, alkaline cleaning formulations will not remove existing

[0013] 30 limescale stain.

[0014] There is therefore a continuing need for alkaline cleaning products that also provide for limescale removal. P0000882 CPL

[0015] 2

[0016] Sequestrants are known and used in cleaning compositions for their chelating properties of metal ions including Ca2+ and Mg2+ thereby inhibiting the formation of limescale and enhancing the antibacterial efficacy of e.g. quaternary ammonium compounds as the low availability of Ca2+ and Mg2+ interferes with cell wall formation by bacteria.

[0017] 5

[0018] For example, sequestrants are added to cleaning compositions to boost the antibacterial efficacy of quaternary ammonium compounds, the latter being known antibacterial agents. Sequestrants are also included in cleaning compositions to prevent the formation of limescale, for example because drying water droplets on a surface may leave limescale deposits. One such known use is the addition of sequestrants to machine dishwash rinse aid products.

[0019] In bleach products, small amounts of sequestrants can be added to aid the stability of hypochlorite by sequestering trace amounts of metals which will otherwise catalyze the decomposition of the hypochlorite.

[0020] 15 Summary of the Invention

[0021] We have now surprisingly found that certain sequestrants when used at high pH show efficacy against already formed limescale deposits and can thus be used as limescale removers.

[0022] Accordingly, in a first aspect the invention relates to an aqueous alkaline liquid cleaning

[0023] 20 composition comprising

[0024] • 0.25 to 10 wt% of sequestrant, wherein the sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and / or its salt;

[0025] • 0.1 to 25 wt% of a surfactant system selected from anionic surfactant, non-ionic surfactant, amphoteric surfactant and combinations thereof;

[0026] • a hypochlorite salt; and

[0027] • water; wherein the composition has a pH of from 12 to 14.

[0028] The invention further relates to a method of removing limescale deposits from a hard surface

[0029] 30 using the composition of the invention as well as use of sequestrant agent in an aqueous alkaline liquid cleaning composition for removing limescale deposits from a hard surface P0000882 CPL

[0030] 3

[0031] Detailed Description of the Invention

[0032] 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

[0033] 5 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

[0034] 10 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 25 degrees Celsius.

[0035] Sequestrant

[0036] The composition comprises 0.25 to 10 wt% of sequestrant. Preferably the composition comprises 0.3 to 8 wt%, more preferably 0.35 to 5 wt% and even more preferably 0.4 to 3 wt%

[0037] 20 of sequestrant.

[0038] It was found that only specific sequestrants will provide for removal of existing limescale deposits, therefore the sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and / or its salt. It will be understood that suitable sequestrants include both the acid form and salts thereof.

[0039] Surfactant

[0040] The composition comprises a surfactant system selected from anionic surfactant, non-ionic surfactant, amphoteric surfactant and combinations thereof. The surfactant system is present in an amount of 0.1 to 25 wt%.

[0041] 30

[0042] The composition may comprise at least 0.1 wt%, more preferably at least 0.2 wt%, even more preferably at least 0.3 wt%, still more preferably at least 0.4 wt% and most preferably at least 0.5 wt% of the surfactant system. The composition preferably comprises at most 20 w%, more preferably at most 18 wt%, even more preferably at most 15 wt%, furthermore preferably at P0000882 CPL

[0043] 4 most 12 wt%, yet more preferably at most 10 wt%, still more preferably at most 8 wt%, and most preferably at most 5 wt% of the surfactant system.

[0044] The surfactant may be present in an amount of 0.25 to 20 wt%, more preferably 0.5 to 15 wt%

[0045] 5 and even more preferably 1 to 10 wt% like for example 0.5 to 5 wt%.

[0046] Anionic surfactant

[0047] The composition may comprise an anionic surfactant. Typically, anionic surfactant helps in boosting cleaning efficacy. The anionic surfactant may present in an amount 0.1 to 20 wt%,

[0048] 10 more preferably 0.2 to 18 wt%, even more preferably 0.3 to 15 wt%, furthermore preferably 0.4 to 12 wt%, yet more preferably 0.5 to 10 wt%, still more preferably 0.5 to 8 wt%, and most preferably 0.5 to 5 wt% calculated on total amount of composition.

[0049] Preferred anionic surfactants are of the organic sulphates and sulfonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term “alkyl” being used to include the alkyl portion of higher acyl radicals. Examples of such materials include alkyl sulphates, alkyl ethoxylated sulphates, alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof.

[0050] The alkyl ethoxylated sulphate may have a normal or branched chain alkyl group containing

[0051] 20 lower ethoxylated groups with two or three carbon atoms. A general formula of such surfactants is given by:

[0052] RO(C2H4O)x SO3-M+ where R is a C8 to C22 alkyl group, saturated or unsaturated, M is a cation which makes the compound water-soluble, especially an alkali metal, ammonium or substituted ammonium

[0053] 25 cation or alkanolamine, and x averages from 1 to 30. Preferably R is a C8 to C18 alkyl group, more preferably C8 to C16 alkyl group, M is sodium and x averages from 1 to 3, more preferably x is 1.

[0054] Preferably, the alkyl ethoxylated sulphate has an C8 to C18 alkyl group with 1 to 30 ethoxylated unit. Preferably the alkyl ethoxylated sulphate has a straight or branched chain alkyl group having 12 to 14 carbon atoms and containing an average of 1 to 7 ethylene oxide (EO) units per molecule. A preferred example is lauryl ether sulphate (LES) with a counterion, in which the predominantly C12 lauryl alkyl group has been ethoxylated with an average of 3 ethylene oxide (EO) units per molecule. Preferably the counterion is selected from alkali metal, such as,

[0055] 35 sodium, potassium. Ammonium or substituted ammonium cation or alkanolamine based P0000882 CPL

[0056] 5 counterions, such as, monoethanolamine (MEA), diethanolamine (DEA) or triethanolamine (TEA), monoisopropanolamine, monoisopropylamine, triisopropanolamine (TIPA) may also be considered.

[0057] 5 Other examples of suitable alkyl ethoxylated sulphate surfactants that could be used in the present invention are C12 to C15 normal or primary alkyl tri-ethoxy sulphate, sodium salt; n- decyl di-ethoxy sulphate, sodium salt; C12 primary alkyl di-ethoxy sulphate, ammonium salt; C12 primary alkyl tri-ethoxy sulphate, sodium salt; C15 primary alkyl tetra-ethoxy sulphate, sodium salt; mixed C14 to C15 normal primary alkyl mixed tri- and tetra-ethoxy sulphate,

[0058] 10 sodium salt; stearyl penta-ethoxy sulphate, sodium salt; and mixed C10 to C15 normal primary alkyl tri-ethoxy sulphate, potassium salt. It is particularly preferred that the alkyl ethoxylated sulphate is sodium lauryl ethoxylated sulphate (SLES). It is the sodium salt of lauryl ethoxylated sulphonic acid in which the predominantly C12 (lauryl) alkyl group is ethoxylated with an average of 1 to 30 moles of ethylene oxide per mole, more preferably 1 to 15 moles of ethylene oxide per mole, still more preferably 1 to 7 moles of ethylene oxide per mole of SLES

[0059] Alkyl aryl sulphonate suitable for the invention include alkylbenzene sulphonate. The alkylbenzene sulphonate may have a linear alkyl chain with 10 to 18 carbon atoms. Commercial linear alkylbenzene sulphonate (LAS) is a mixture of closely related isomers and homologues

[0060] 20 alkyl chain homologues, each containing an aromatic ring sulfonated at the “para” position and attached to a linear alkyl chain at any position except the terminal carbons. The linear alkyl chain typically contains 11 to 15 carbon atoms, predominantly 12 carbon atoms. Each alkyl chain homologue consists of a mixture of all the possible sulpho-phenyl isomers except for the 1 -phenyl isomer. The linear alkylbenzene sulphonate is normally formulated into compositions

[0061] 25 in acid (i.e. , HLAS) form and then at least partially neutralized in-situ. Preferably the counterion is selected from alkali metal, such as, sodium, potassium. Ammonium or substituted ammonium cation or alkanolamine based counterions, such as, monoethanolamine (MEA), diethanolamine (DEA) or triethanolamine (TEA), monoisopropanolamine, monoisopropylamine, triisopropanolamine (TIPA) may also be considered.

[0062] The composition may further comprise anionic surfactants such as alkyl sulphate surfactant (PAS), non-ethoxylated primary and secondary alkyl sulphates having alkyl chain length with 10 to 18 carbon atoms. P0000882 CPL

[0063] 6

[0064] Non-ionic surfactant

[0065] The composition may comprise a non-ionic surfactant. Preferably the non-ionic surfactant is selected from alcohol ethoxylate, alkyl polyglycoside and combinations thereof.

[0066] 5 Preferably the non-ionic surfactant is present in an amount from 0.1 to 20 wt%, more preferably 0.2 to 18 wt%, even more preferably 0.3 to 15 wt%, furthermore preferably 0.4 to 12 wt%, yet more preferably 0.5 to 10 wt%, still more preferably 0.5 to 8 wt%, and most preferably 0.5 to 5 wt% calculated on total amount of composition.

[0067] Preferably the non-ionic surfactant comprises alcohol ethoxylate. Suitable alcohol ethoxylates include water soluble aliphatic ethoxylated non-ionic surfactants including the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. This includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 20 moles of ethylene oxide, for

[0068] 15 example, lauryl or myristyl alcohol condensed with about 10 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 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

[0069] 20 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.

[0070] Examples of the foregoing non-ionic surfactants include, but are not limited to, the Neodol® (Shell), which are higher aliphatic, primary alcohol containing about 9 to 15 carbon atoms, such as C9 to C11 alkanol condensed with 4 to 10 moles of ethylene oxide (Neodol® 91-8 or

[0071] 25 Neodol® 91-5), C12 to C13 alkanol condensed with 6.5 moles ethylene oxide (Neodol® 23- 6.5), C12 to C15 alkanol condensed with 12 moles ethylene oxide (Neodol® 25-12), C14 to C15 alkanol condensed with 13 moles ethylene oxide (Neodol® 45-13), and the like.

[0072] Examples of the non-ionic surfactant include the class of the fatty alcohol ethoxylate and are sold under the trade names of Brij® 35, Brij® 97, Brij® 700, Brij® 99, Brij® 56, Brij® 76, C12EO7, and Brij S10. Preferred non-ionic surfactants of the fatty acid ethoxylate class are sold under the brand names of MyrjTM S20, MyrjTM S40, MyrjTM S40, MyrjTM S50, and PEG-100 stearate. Preferred non-ionic surfactants of the polyoxyethylene sorbitan alkyl esters class are sold under the brand names of Tween® 21, Tween® 20, Tween® 40, Tween® 60, Tween® 65

[0073] 35 tri-stearate, Tween® 85 trioleate, and Tween® 80. Preferred non-ionic surfactants of the alkyl P0000882 CPL

[0074] 7 phenol ethoxylate class are sold under the brand names of TritonTM X114, TritonTM X100, TritonTM X102, TritonTM X165, TritonTM X305, TritonTM X405 or TritonTM X705. It is observed that the above-mentioned non-ionic surfactants all have an HLB value higher than 10.

[0075] 5 Preferably the non-ionic surfactant is selected from the class of poly-oxyethylene sorbitan alkyl ester. These surfactants are available under the trade name Tween® or TritonTM, for example, Tween® 20 (polyoxyethylene sorbitan monolaurate, HLB=16.7), Tween® 40(polyoxyethylene sorbitan mono-palmitate, HLB=15.6),Tween® 60 (polyoxyethylene sorbitan monostearate, HLB=14.9), Tween® 65 (polyoxyethylene sorbitan tristearate, HLB=10.5), Tween® 80 (polyoxyethylene sorbitan monooleate, HLB=15.0), Tween® 85 (polyoxyethylene sorbitan trioleate, HLB=11.0), TritonTM (octyl phenol Ethoxylates), e.g., HLB=12.3), TritonTM X114 (HLB =12.3), Triton ( HLB=13.4), TritonTM X102(HLB=14.4), TritonTM X305(HLB=17.3), TritonTM X405( HLB=17.3), TritonTM X705 ( HLB=18.4) etc.

[0076] 15 The other non-ionic surfactants suitable for the present invention include alkyl polyglycoside, poly-oxyethylene sorbitan alkyl esters and alkyl phenol ethoxylates.

[0077] The non-ionic surfactant in the composition may be an alkyl polyglycoside. As used herein alkyl polyglycosides are compounds having formula R1O(R2O)b(Z)a, wherein R1 is a alkyl radical,

[0078] 20 having from about 8 to about 10 carbon atoms; R2 is an alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; and a is a number having a value from 1 to about 6 (the degree of polymerization). Due to the method by which they are synthesized, alkyl polyglycosides are generally present as mixtures of alkyl polyglycosides having varying amounts of carbon atoms

[0079] 25 in the alkyl radical and varying degrees of polymerization. Thus, when referring to alkyl polyglycosides, the alkyl radical is generally referred to as having a range of carbon atoms (e.g., C8 / 10 referring to a range of alkyl radicals having from 8 to 10 carbon atoms) and the degree of polymerization is generally referred to as the average degree of polymerization of the mixture.

[0080] Preferred alkyl polyglycosides suitable for the invention include those having the formula R1O(R2O)b(Z)a, wherein R1 is a alkyl radical, having from about 8 to about 10 carbon atoms; R2 is an alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; and a is a number having a value from 1 to about 6 (the degree of polymerization). Preferred alky polyglycoside are those

[0081] 35 where Z is a glucose residue, b is zero, R1 is an alkyl group that contains 8 to 10 carbon atoms, P0000882 CPL

[0082] 8 and the average value of a is about 1 to 2. Such alkyl polyglucosides are commercially available, for example, as Glucopon® branded alkyl polyglucoside compositions from BASF (formerly Cognis Corporation), including Glucopon® 215CS UP and 225 DK.

[0083] 5 Amphoteric surfactant

[0084] The composition may comprise an amphoteric surfactant. The amphoteric surfactant may present in an amount 0.1 to 20 wt%, more preferably 0.2 to 18 wt%, even more preferably 0.3 to 15 wt%, furthermore preferably 0.4 to 12 wt%, yet more preferably 0.5 to 10 wt%, still more preferably 0.5 to 8 wt%, and most preferably 0.5 to 5 wt% calculated on total amount of composition.

[0085] Examples of the amphoteric surfactant suitable for the present invention include alkyl amido propyl betaines, alkyl sulpho-betaines and amine oxides.

[0086] 15 Examples of suitable amphoteric surfactant include, cocodimethyl sulphopropyl betaine, lauryl betaine, sodium cocamphopropionate, cocam idopropyl betaine (CAPB), cocodiethanol amide (CDEA) and cocomonoethanol amide (CMEA).

[0087] Preferred amine oxides are alkyl dimethyl amine oxide and alkyl amido propyl dimethyl amine

[0088] 20 oxide, more preferably alkyl dimethyl amine oxide. Especially preferred are lauryl dimethylamine oxide, coco dimethyl amine oxide and coco amido propyl dimethyl amine oxide.

[0089] Cationic surfactant

[0090] In addition to the surfactants that may be present as part of the surfactant system, cationic

[0091] 25 surfactants may sometimes be desired as some cationic surfactants like quaternary ammonium compounds 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.

[0092] Water

[0093] The composition is an aqueous composition. The term ‘aqueous’ herein refers to water, and the composition contains significant amount of water. More particularly water acts as balance in the

[0094] 35 composition. P0000882 CPL

[0095] 9

[0096] Water may be present in the composition in an amount from 60 to 99 wt%, more preferably 60 to 95 wt% and most preferably 60 to 90 wt%. Preferably the composition when formulated as concentrate, may contain 60 to 80% by weight, more preferably 65 to 80% by weight and most preferably 70 to 80% by weight of water.

[0097] 5

[0098] Further ingredients

[0099] The composition according to the present invention may include additional ingredients to improve or enhance the in-use performance. Such ingredients include colour, soil suspending agents, foam boosters, antimicrobial agent, preservative, performance boosting polymers, freeze-thaw stabilisers, hydrotrope, and perfumes.

[0100] The composition may comprise a quaternary ammonium compound, preferably for antimicrobial or hygiene benefit. Examples of quaternary ammonium compounds include alkyl ammonium halides such as cetyl trimethyl ammonium bromide, alkyl aryl ammonium halides such as

[0101] 15 octadecyl dimethyl ammonium bromide, N-alkyl pyridinium halides such as N-cetyl pyridinium bromide, and the like. One suitable type of quaternary ammonium compound includes, for example, those in which the molecules contain amine, ether or ester linkages such as octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, N-(lauryl coco amino formyl methylpyridinium chloride, and the like. Another effective type of quaternary ammonium compound

[0102] 20 includes, for example, those in which the hydrophobic radical is characterized by a substituted aromatic nucleus as the case of lauryl oxy-phenyl trimethyl ammonium chloride, cetyl amino phenyl trimethyl ammonium methosulphate, dodecyl phenyl trimethyl ammonium methosulphate, dodecyl benzyl trimethylammonium chloride, chlorinated dodecyl benzyl trimethyl ammonium chloride, and the like. Preferably, the quaternary ammonium compound

[0103] 25 utilized in the practice of the present technology exhibit biocidal activity or are biocidal in nature.

[0104] Examples of suitable quaternary ammonium compounds suitable for the present invention include di-decyl dimethylammonium chloride, dioctyl dimethylammonium chloride, alkyl dimethyl benzyl ammonium chloride, di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, alkyl dimethyl benzyl ammonium saccharinate, octyl decyl dimethyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chloride, methyl dodecyl benzyl ammonium chloride, methyl dodecyl xylene-bis-trimethyl ammonium chloride, methyl benzethonium chloride, cetyl pyridinium chloride, cetrimonium bromide. Polymeric quaternary ammonium salts based on these monomeric structures may also be considered for the present invention.

[0105] 35 P0000882 CPL

[0106] 10

[0107] The composition may further comprise a preservative for its known purpose. Particularly eco- friendly preservatives are more preferred. ‘IT’ based preservatives, such as benzisothiazolinone (BIT), octylisothiazolinone (OIT), methylchloroisothiazolinone (MCIT), methylisothiazolinone (MIT) may be avoided for the purpose of the present invention. Preferably the composition does

[0108] 5 not contain said ‘IT’ based preservatives, particularly benzisothiazolinone (BIT).

[0109] Alkaline composition

[0110] The present cleaning composition is an alkaline composition having a pH of from 12 to 14 as measured at room temperature. Such to allow for application on acid sensitive hard surfaces like marble. Preferably the composition has a pH of from 13 to 14.

[0111] Bleach composition

[0112] As the compositions of the invention are alkaline, they are suitable to comprise hypochlorite that otherwise would react and decompose in an acidic composition.

[0113] 15

[0114] The composition of the present invention comprises a hypochlorite salt, wherein the sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and wherein the composition has a pH of 12 to 14.

[0115] 20 Such a composition allows for disinfection as well as removal of limescale deposits on hard surfaces. For the avoidance of doubt, this concerns already deposited limescale stains.

[0116] The composition preferably comprises 0.1 to 10 wt% of hypochlorite salt, more preferably 1 to 8 wt% and even more preferably 2 to 5 wt%.

[0117] 25

[0118] Preferably the hypochlorite salt is sodium hypochlorite.

[0119] Preferably the composition comprises at least 0.01 mol / l hypochlorite ion as measured on total volume of the liquid cleaning composition.

[0120] The compositions according to the invention are particularly suitable to be used as is, i. e. without prior dilution. In order to be conveniently dispensed from suitable containers whilst also clinging to inclined surfaces they preferably have a viscosity of 20-5000mPa. s, preferably 100-

[0121] 35 2000 mPa. s, more preferably 200-1000 mPa. s (measured with a Haake RT20 Rotovisco P0000882 CPL

[0122] 11 rheometer fitted with a coaxial cylinder sensor DIN 53018 (Z41 rotor and Z43 measuring cylinder), using a 3 mm gap. Flow curves were obtained at 25' C over the shear rate range 0. 1 to 1000 s ').

[0123] 5 Product format

[0124] The composition may be used neat or diluted. For hard surface cleaning, the composition is typically applied neat directly to the surface or on an implement like for example a sponge or cloth.

[0125] 10 A typical means of applying the composition is with spray dispenser, also known as trigger spray, wherein the composition is held in a bottle container that is fitted with a spray head. The spray head will disperse the composition as a liquid spray or as a foam. The present composition is preferably applied on the hard surface as a foam using a foam trigger sprayer as the foam will allow for good and prolonged surface coverage allowing the composition to remove limescale deposits from the hard surface. For such an application the composition preferably is water thin or at least suitable to be used with a trigger spray.

[0126] For toilet applications, the composition can be applied with a trigger spray or as a liquid that is applied directly on the hard surface from the bottle thereby covering the hard surface with a film

[0127] 20 of the composition. For such an application in liquid form the composition preferably has a ticker consistency and thus a certain viscosity such that it clings better to the hard surface and on vertical surfaces like in a toilet bowl only slowly slides down allowing for prolonged exposure time.

[0128] 25 Method

[0129] The invention also relates to a method of removing limescale deposits from a hard surface comprising the steps of a. applying the composition of the present invention to the hard surface; b. optionally leaving the composition on the hard surface for a period of at least 30

[0130] 30 seconds; and c. optionally rinsing the surface with water.

[0131] The composition is applied as a layer of the product, for example as a thin liquid film or as a foam. In the context of the present invention, “applying” is defined as excluding submerging a P0000882 CPL

[0132] 12 product with a hard surface in a volume of the cleaning composition or exposing a hard surface to more than 100 ml, preferable more than 50 ml of the cleaning composition.

[0133] The method of removing limescale deposits from a hard surface is preferably performed at

[0134] 5 ambient temperature. Ambient temperature excludes situations where the hard surface is deliberately subjected to heat with the aim to raise the temperature of said hard surface.

[0135] Preferably the composition is left on the hard surface for at least 30 seconds, more preferably at least 1 minute, even more preferably at least 10 minutes and still even more preferably at least 30 minutes. Such to allow the sequestrant to remove limescale deposits present.

[0136] Use

[0137] The invention further relates to the use of 0.25 to 10 wt% of sequestrant in an aqueous alkaline liquid cleaning composition for removing limescale deposits from a hard surface, wherein the

[0138] 15 sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and / or its salt.

[0139] Preferably the sequestrant is used in the composition of the invention.

[0140] Examples

[0141] 20

[0142] Limescale removal test

[0143] 1. Soak shine stainless steel tiles in ethanolic KOH solution for 1 hour.

[0144] 2. Rinse the tiles vigorously with tap water, using a non-abrasive sponge and leave to dry.

[0145] 3. Create hard water by making and leaving a suspension at room temperature with an excess

[0146] 25 of fine calcite for 30 minutes (CaCO315g / l) after which it is filtered.

[0147] 4. Heat the test tiles in an oven set at 240°C.

[0148] 5. Spray hard water on the heated tiles to fix the limescale (1 Layer of limescale).

[0149] 6. Apply an adhesive mask, masking part of the Layer, and create a frame of limescale soil using a citric acid solution of 10% to remove the limescale soil layer not covered by the adhesive mask. Remove the adhesive mask to reveal the limescale soil layer.

[0150] 7. Dip the tiles in the test solution for 10, 30 or 60 mins.

[0151] 8. Visually assess the % of removal of the limescale soil layer.

[0152] 35 P0000882 CPL

[0153] 13

[0154] Non-bleach containing formulations

[0155] The sequestrants as in Table 1 were tested in formulation I as in Table 2. The formulations were tuned to the pH as indicated and tested for limescale removal using the protocol as described above. The pH and limescale removal results are given in Table 3.

[0156] TABLE 1, Tested sequestrants non-bleach containing formulations

[0157] TABLE 2, Formulation I (wt% calculated on total product, water to 100)

[0158] 10 TABLE 3, Test results limescale removal (100% removal = pass) P0000882 CPL

[0159] 14

[0160] All wt% respond to 0.0011 mol of the ingredient.

[0161] Sequion CLR: nitrilotris(methylene)]trisphosphonic acid N-oxide, also referred to as AMP-NO; MGDA: alanine, N,N-bis(carboxymethyl)-, sodium salt (1 :3); GLDA: tetrasodium glutamate diacetate; PESA: polyepoxysuccinic acid.

[0162] 5 pH of formulation was reached by tuning with NaOH and Na2CO3.

[0163] Bleach containing formulations

[0164] The sequestrants as in Table 4 were tested in formulations A to C as in Tables 5A to 5C. The formulations were tuned to pH 12 and tested for limescale removal using the protocol as

[0165] 10 described above. The pH and limescale removal results are given in Table 6.

[0166] TABLE 4, Tested sequestrants bleach containing formulations

[0167] TABLE 5A, Formulation A (wt% calculated on total product, water to 100) P0000882 CPL

[0168] 15

[0169] TABLE 5B, Formulation B (wt% calculated on total product, water to 100)

[0170] TABLE 5C, Formulation C (wt% calculated on total product, water to 100)

[0171] TABLE 6, Test results limescale removal (100% removal = pass)

[0172] All wt% respond to equal moles of the ingredients for direct comparison.

[0173] Sequion CLR: nitrilotris(methylene)]trisphosphonic acid N-oxide, also referred to as AMP-NO;

[0174] PESA: polyepoxysuccinic acid.

[0175] 10 pH of formulation was reached by tuning with NaOH and sodium silicate.

Claims

P0000882 CPL16Claims1. An aqueous alkaline liquid cleaning composition comprising• 0.25 to 10 wt% of sequestrant, wherein the sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and / or its salt;• 0.1 to 25 wt% of a surfactant system selected from anionic surfactant, non-ionic surfactant, amphoteric surfactant and combinations thereof;• a hypochlorite salt; and• water; wherein the composition has a pH of from 12 to 14.

2. Composition according to claim 1 wherein the amount of sequestrant is from 0.3 to 5 wt%, preferably from 0.35 to 3 wt% and more preferably from 0.4 to 2 wt%.

3. Composition according to claim 1 or 2 wherein the composition has a pH of from 13 to 14.

4. Composition according to any one of claims 1 to 6 wherein the amount of surfactant system is 0.25 to 20 wt%, preferably 0.5 to 15 wt% and more preferably 1 to 10 wt%.

5. Composition according to any one of claims 1 to 4 wherein the amount of hypochlorite salt is from 0.1 to 10 wt%, preferably 1 to 8 wt%, more preferably 2 to 5 wt%.

6. Composition according to any one of claims 1 to 5 comprising at least 0.01 mol / l hypochlorite ion measured on total volume of the liquid cleaning formulation.

7. Composition according to any one of claims 1 to 6 wherein the hypochlorite salt is sodium hypochlorite.

8. Composition according to any one of claims 1 to 7 wherein the composition has a viscosity of 20-5000 mPa.s.P0000882 CPL179. Method of removing limescale deposits from a hard surface comprising the steps of a. applying the composition according to any one of claims 1 to 8 to the hard surface; b. optionally leaving the composition on the hard surface for a period of at least 30 seconds; and c. optionally rinsing the surface with water.

10. Method according to claim 9 wherein the composition is left on the hard surface for at least 30 seconds, preferably at least 1 minute, more preferably at least 10 minutes and even more preferably at least 30 minutes.

11. Use of 0.25 to 10 wt% of sequestrant in an aqueous alkaline liquid cleaning composition for removing limescale deposits from a hard surface, wherein the sequestrant is nitrilotris(methylene)trisphosphonic acid N-oxide and / or its salt.

12. Use according to claim 12 wherein the composition is according to any one of claims 1 to 8.

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