Methanesulfonic acid hard surface cleaning composition
FIELD OF THE INVENTION
The presently claimed invention is in the field of cleaning agents. In particular, it relates to a cleaning composition, more in particular to a composition comprising methanesulfonic acid. The composition provides good cleaning, in particular good cleaning of hard surface.
BACKGROUND OF THE INVENTION
The presently claimed invention relates to improved cleaning compositions which find particular use in hard surface cleaning applications. Hard surface cleaning compositions have been known and used in a variety of applications, including bathrooms, kitchens and other areas, particularly for toilets, showers, bathtubs, sinks, tiles, countertops, walls, doors and the like. Often times, hard surfaces accumulate both soap scum stains, which are typically residues of various types of soaps used in a household, as well as hard water stains, which are typically the result of the deposition of calcium, barium and lime or various salts on hard surfaces over the course of time and use of various household surfaces. Cleaning solutions for these household surfaces have been formulated to address both the removal of soap scum stains, as well as the descaling of hard water stains. In particular, many of these cleaning solutions have employed a combination of components, in a number of instances including strong inorganic acids, organic acids or a combination of both, a surfactant or wetting agent, a solvent and a diluent to address one or both of these types of stains and/ or build-ups.
Acids are an indispensable ingredient for the modern cleaning formulations. Their superior cleaning performance on lime scale removal combined with ease of incorporation makes them the pick of choice for cleaning agent formulators. The acids like hydrochloric acid, nitric acid, phosphoric acid, sulphamic acid, citric acid, formic acid, sulphuric acid and acetic acid are frequently used in cleaning formulations.
However there are several drawbacks associated with cleaning compositions comprising these acids for example: toxic fumes, corrosion and long storage stability. Hence there is a strong need to develop a cleaning composition which is biodegradable, does not release toxic fumes and has long storage stability.

Thus, it was an object of the presently claimed invention to provide cleaning compositions that effectively remove stain, in particular lime scale, from hard surfaces, in particular marble, without showing the side effects of conventionally used cleaning compositions such as release of toxic fumes.
SUMMARY OF THE INVENTION
The object was solved by the inventively claimed cleaning composition.
Accordingly, the presently claimed invention is directed to a cleaning composition comprising:
a) ≥ 1 to ≤ 20 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.5 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 10 wt-% of at least one surfactant;
d) ≥ 80 to ≤ 98 wt-% of at least one solvent; and
e) ≥ 0.0 to ≤ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
According to the first aspect of the invention, there is provided a cleaning composition. The composition comprises methanesulfonic acid, xanthan gum, surfactant and solvent. The composition provides excellent stain removal from all types of hard surfaces. Preferably the composition is for cleaning of surface soils such as hard water stains, soap scum, lime scale, mud, food, toilet stains, oil, grease, particulates and the like.
According to second aspect of the presently claimed invention, there is provided a method of cleaning hard surface using the composition comprising methanesulfonic acid, xanthan gum, surfactant and solvent.
According to third aspect of the invention, there is provided a method of preparation of the cleaning composition methanesulfonic acid, xanthan gum, surfactant and solvent.
DETAILED DESCRIPTION ON THE INVENTION

The presently claimed invention envisages a cleaning composition, preferably a hard surface cleaning composition, comprising methanesulfonic acid, xanthan gum, surfactant and solvent. The composition of the invention provides very good stain, scale and rust removal. The invention also envisages a method of cleaning hard surface by using the composition for the removal of stain, scale and rust.
According to the presently claimed invention hard surfaces include surfaces composed of a refractory material selected from the group consisting of glazed and unglazed tile, porcelain, ceramics, stone, marble, granite, glass, metals, plastics e.g. polyester, vinyl and fiberglass.
Hard surfaces which are to be particularly denoted are lavatory fixtures such as shower stalls,
bathtubs and bathing appliances (racks, shower doors, shower bars), toilets, bidets, wall and flooring surfaces especially those which include refractory materials and the like. Further hard surfaces which are to be denoted are those associated with kitchen environments and other environments associated with food preparation, including cabinets and countertop surfaces as well as walls and floor surfaces especially those which include refractory materials.
The cleaning composition can be used in various hard surface cleaning applications including for example: toilet bowl, bathroom surfaces and wash basins. The cleaning composition can also be used in various industries including but not limited to homecare, ware wash, food and beverages, car care, health care, and industrial & institutional (l&l) cleaning.
The presently claimed invention relates to a hard surface cleaning composition comprising:
a) 1 to 20 wt-% of methanesulfonic acid;
b) 0.1 to 4 wt-% of xanthan gum;
c) 0.1 to 10 wt-% of surfactant; and
d) ad 100 wt- % of solvent.
The cleaning composition of the presently claimed invention is suitable for hard surface cleaning. As such, the composition is referred to as a hard surface cleaning composition and cleaning composition, respectively. The composition according to

the presently claimed invention may be provided in different forms such as liquids, gels, pastes, spray able liquids, foams, solid blocks, etc. Preferably, the composition of the presently claimed invention is provided in liquid form.
The cleaning composition provided in and to be prepared in context with the presently claimed invention may contain a solvent in which the other components are dissolved, dispersed or suspended. The solvent is contained in the composition of the presently claimed invention in an amount such as to arrive at 100% together with the other components as defined herein. It is also possible in context with the presently claimed invention to combine two or more different solvents. Solvent is as further defined herein below.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may contain from about 0.1 to 20wt-%, preferably from 1 to 10wt-%, more preferably from 2 to 5wt-%, even more preferably from 2 to 4 wt-%, of methanesulfonic acid (MSA). In context with the method of preparing a cleaning composition in accordance with the presently claimed invention as described and provided herein, the MSA may also be applied or added to the composition in liquid form, e.g., solved in in a suitable solvent such as water (e.g., 50-70% MSA in water). Use may be made of methanesulfonic acid in aqueous solution sold under the name Lutropur® sold by BASF with water in the proportions indicated above.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention preferably contains from 0.1 to 1.0wt-%, of xanthan gum as further defined herein below.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may contain from about 0.1 to 10wt-%, preferably from 0.1 to 5wt-%, more preferably from 0.5 to 2wt-%, of surfactant as further defined herein below.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may further contain antimicrobial agents or biocidal substance as further defined herein below.

In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may further contain fragrance as further defined herein below.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may further contain chelants as further defined herein below.
In an embodiment, the cleaning composition provided in and to be prepared in context with the presently claimed invention may further contain colors as further defined herein below.
The presently claimed invention further provides a method of cleaning hard surface by applying the cleaning composition of the presently claimed invention to the hard surface; and rinsing the hard surface.
Preferably the hard surface includes surfaces composed of a refractory material selected from the group consisting of glazed and unglazed tile, porcelain, ceramics, stone, marble, granite, glass, metals, plastics e.g. polyester, vinyl and fiberglass.
The presently claimed invention further provides a method of preparing a cleaning composition of the present invention comprising:
a) preparation of premix by mixing xanthan gum and a surfactant as defined herein, optionally further admixing a fragrance, chelant, adjuvant, color, microbial and/or biocidal substance as defined herein;
b) addition of the premix of a) to a solvent, preferably under constant stirring;
c) preparation of a solution of methanesulfonic acid and optionally a solvent; and
d) addition of solution of c) to the mixture of b).
In another embodiment the presently claimed invention is directed to a method of preparing the composition as described above comprising the steps of:
A) preparation of premix by mixing b) xanthan gum and c) at least one surfactant, optionally further admixing e) at least one additive;
B) addition of the premix obtained from step A) to d) at least one solvent, preferably under constant stirring;

C) preparation of a solution of a) methanesulfonic acid and optionally d) at least one solvent; and
D) addition of the solution obtained from step C) to the mixture obtained from step B).
The presently claimed invention also relates to the use of methanesulfonic acid as an ingredient for cleaning of hard surfaces. Methanesulfonic acid is organic in nature and has the property of being fully bio-degradable. Methanesulfonic acid exhibits excellent scale dissolution efficiency and is further found to exhibit reduced corrosion on the surfaces to be cleaned. The cleaning efficiency was found to be significantly higher compared to other organic acids like citric acid, acetic acid, and lactic acid, etc, which are often used in hard surface cleaning compositions. The improved scale dissolution and soap scum removal property combined with the superior material compatibility and bio-degradability provide it with a unique position among acids used for cleaning purpose. One of the popular applications of acids as cleaning ingredient has been in the cleaning of acidic toilet bowls. Usual acids employed in this context are hydrochloric, citric, formic and phosphoric acid. In some cases, such hard surface cleaning compositions may also be based on bleaching agents like sodium hypochlorite, hydrogen peroxide or sodium dithionite. In either case, the key characteristic of the finished composition is high viscosity combined with a strong acid stable fragrance. The high viscosity ensures more residence time of the cleaning solution over the affected area.
Preferably the inventively claimed composition does not contain any acid selected from the group consisting of hydrochloric acid, nitric acid, phosphoric acid, sulphamic acid, citric acid, formic acid, sulphuric acid and acetic acid.
In a preferred embodiment the presently claimed invention is directed to a cleaning composition comprising:
a) ≥ 1 to ≤ 10 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.0 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 5 wt-% of at least one surfactant selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants;
d) ≥ 90 to ≤ 98 wt-% of at least one solvent selected from the group consisting of water, isopropyl alcohol, propylene glycol, sorbitol, polyethylene glycol, glycerol, polypropylene glycol and ethanol; and

e) ≥ 0.0 to ≤ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
In another preferred embodiment the presently claimed invention is directed to a cleaning composition consisting of:
a) ≥ 1 to ≤ 10 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.0 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 5 wt-% of at least one surfactant selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants;
d) ≥ 90 to ≤ 98 wt-% of at least one solvent selected from the group consisting of water, isopropyl alcohol, propylene glycol, sorbitol, polyethylene glycol, glycerol, polypropylene glycol and ethanol; and
e) ≥ 0.0 to ^ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
In yet another preferred embodiment the presently claimed invention is directed to a cleaning composition comprising:
a) ≥ 1 to ≤ 10 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.5 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 5 wt-% of at least one surfactant selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants;
d)≥ 90 to ≤ 98 wt-% of water; and e) ≥ 0.0 to ≤ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
In yet another preferred embodiment the presently claimed invention is directed to a cleaning composition comprising:
a) ≥ 1 to ≤ 10 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.5 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 5 wt-% of at least one surfactant selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants; and
d)≥ 90 to ≤ 98 wt-% of water;

whereby the sum of the weight percentages of the components a), b), c) and d) adds up to100 wt-%.
Solvent:
The solvent is preferably used to dissolve various components in the cleaning composition so as to form a substantially uniformly dispersed mixture.
The solvent, when used, can be premixed with the other components of the cleaning composition or be partially or fully added to the cleaning composition prior to use. The solvent may be water soluble and/or it is a water dispersible organic solvent. Suitable solvents include, but are not limited to, water, isopropyl alcohol, propylene glycol, sorbitol, polyethylene glycol, glycerol, polypropylene glycol, ethanol and mixtures thereof. A particularly preferred solvent may be water.
The term "ad" shall mean "up to", for example ad 100% solvent means up to 100% solvent.
Xanthan gum:
The cleaning composition as provided herein and as to be employed in the preparation method provided in context with the presently claimed invention includes an effective amount of xanthan gum as a thickener for improving the viscosity, cleaning performance and stabilizing the cleaning composition. In one embodiment of the presently claimed invention, an acid stable xanthan gums may be employed in (preparing) the cleaning composition in accordance with the presently claimed invention. Wherein an acid stable xanthan gum means a xanthan gum which is stable in acidic atmosphere. Particular examples of xanthan gum types to be employed in context with the presently claimed invention comprise inter alia Kelzan® ASX-T (CAS-No. 11138-66-2), Kelzan® AP AS, Kelzan® ASX (all supplied by CP Kelco, USA as of May 18, 2010)), or XG TNAS CS (supplied by Jungbunzlauer)
Surfactant:
The cleaning composition as provided in and to be prepared in context with the presently claimed invention inter alia includes an effective amount of surfactant for improving the cleaning performance, stabilizing the cleaning composition and emulsifying the cleaning components. Conventional nonionic, anionic, cationic, zwitterionic, and/or amphoteric surfactants can be employed. Examples of suitable surfactants are described in McCutcheon's Emulsifiers and Detergents (1997), Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Volume 22, pp. 332-432

(Marcel-Dekker, 1983), and McCutcheon's Soaps andDetergents (N. Amer. 1984), which are incorporated herein by reference.
Suitable surfactants include, but are not limited to, alkyl aryl sulphonates, secondary alkane sulphonates, alkyl methyl ester sulfonates, alpha olefin sulfonates, alkyl ether sulphates, alkyl sulphates, alcohol sulfates, poloxamers, alcohol ethoxylates, amine ethoxylates, alkanolamides, phosphate esters, alkyl polysaccharides, betaines, propionates, alkyl quaternaries, glycoside, glycols, ethylene oxide and mixed ethylene oxide/propylene oxide adducts of alkylphenols and alcohols, the ethylene oxide and mixed ethylene oxide/propylene oxide adducts of long chain alcohols or of fatty acids, mixed ethylene oxide/propylene oxide block copolymers, esters of fatty acids and hydrophilic alcohols, sorbitan monooleates, alkanolamides, soaps, alkylbenzene sulfonates, olefin sulfonates, paraffin sulfonates, propionic acid derivatives, alcohol and alcohol ether sulfates, phosphate esters, amines, amine oxides, alkyl sulfates, alkyl ether sulfates, sar-cosinates, sulfoacetates, sulfosuccinates, cocoamphocarboxy glycinate, salts of higher acyl esters of isethionic acid, salts of higher acyl derivatives of taurine or methyltaurine, phenol poly ether sulfates, higher acyl derivatives of glycine and methylglycine, alkyl aryl polyether alcohols, salts of higher alkyl substituted imadazolinium dicarboxylic acids, tan nics, naphthosulfonates, monochloracetics anthraflavinics, hippurics, anthranilics, naphthoics, phthalics, carboxylic acid salts, acrylic acids, phosphates, alkylamine ethoxylates, ethylenediamine alkoxylates, betaines, sulfobetaines, and imidazolines.
Lauryl sulfate, laurylether sulfate, cocamidopropylbetaine, alkyl polyglycosides, and amine oxides can also be employed as surfactants. The amine oxides can be ethoxylated and/or propoxylated. Non-limiting Examples of amine oxides include, but are not limited to, lauryldimethylamine oxide.
Surfactants may also include ethoxylated alcohols having an alkyl group preferably with 6-22 carbons; the alkyl group is preferably linear but could be branched. Furthermore, the carbon groups can be saturated or unsaturated. Suitable ethoxylated alcohols include the SURFONIC® L series surfactants by Huntsman. Fluorosurfactants can also be used as the surfactant. A suitable fluorosurfactant is an ethoxylated nonionic fluorosurfactant. Suitable ethoxylated nonionic fluorosurfactants include the ZONYL surfactants manufactured by DuPont.

Cationic surfactants include, in particular, alkylammonium salts of formula
R1R2R3R4-NTX-
where X- represents a halide, CH3S04- or C2H5SO4- ions, R1 and R2 are alike or different and represent a C1-C20 alkyl radical or an aryl or benzyl radical, R3 and R4 are alike or different and represent a C1-C20 alkyl radical, an aryl or benzyl radical or an ethylene oxide and/or propylene oxide condensate (Ch2Ch20)x-(Ch2CHCH30)y-H, where x and y range from 0 to 30 and are never simultaneously zero, such as cetyltrimethylammonium bromide.
Other Examples include alkyl quaternary ammonium compounds which contain at least two nitrogen-bonded alkyl chains having at least about 16 carbon atoms such as distearyldiammonium chloride and ditallowdiammonium chloride; C8 to C18 fatty alkyl amines, amidoal-kylamines and amidoalkanolamines, and their salts; ethoxylated amines; amine oxides; and immidazoline.
Antimicrobial substance:
An antimicrobial substance can also be included in the cleaning composition in context with the presently claimed invention. Non-limiting examples of antimicrobial agents include benzalkonium chlorides and/or substituted benzalkonium chlorides, di(C6-C14) alkyldi short chain (C1-4 alkyl and/or hydroxyalkyl) quaternary ammonium salts, N-(3-chloroallyl) hexaminium chlorides, benzethonium chloride, methylbenzethonium chloride, and cetylpyridinium chloride.
The quaternary compounds useful as cationic antimicrobial actives may be selected from the group consisting of dialkyldimethyl ammonium chlorides, alkyldimethylbenzylammonium chlorides, dialkylmethylbenzylammonium chlorides, and mixtures thereof.
Biguanide antimicrobial actives are including, but not limited to, polyhexamethylene biguanide hydrochloride, p-chlorophenyl biguanide; 4-chlorobenzhydryl biguanide, halogenated hexidine such as, but not limited to, chlorhexidine (1,1 '-hexamethylene-bis-5-(4-chlorophenyl biguanide) and its salts are especially preferred. Typical concentrations for biocidal effective-ness of these quaternary compounds, especially in the preferred low-surfactant compositions herein, may range from about 0.001 % to about 3% and preferably from about 0.005% to about 0.3% of the usage composition. The weight percentage ranges for the biguanide and/or quatcompounds in the cleaning composition is selected to disinfect, sanitize, and/or sterilize most

common household and industrial surfaces.
Biocides are also useful in the present compositions. Such biocides can include, but are not limited to, phenolic disinfectants, pine disinfectants, aromatic diamidines, biguanides, biocidal surfactants, aldehydes, anti-microbial dyes, halogens, alcohols, quinoline derivatives, peroxygens, permeabalizers, heavy metal derivatives, anilides, acids, alcohols, peroxides, boric acid and borates, chlorinated hydrocarbons, organometallics, halogen-releasing compounds, mercury compounds, metallic salts, pine oil, organic sulfur compounds, iodine compounds, silver nitrate, quaternary phosphate compounds, and phenolics.
Preferred antimicrobial agents include organic acids, such as, formic, acetic, lactic, sulfamic and glycolic acids.
Colors and Fragrances:
Various colors/dyes, odorants including perfumes, and other aesthetic enhancing agents may also be included in the composition. Color may be included to alter the appearance of the composition or to modify esthetics. The types which can be used include almost all types of acid dyes, direct dyes, basic dyes, mordanting dyes, pigments and polymeric dyestuffs, as for example, any of a verity of FD&C dyes, D&C dyes, and the like. Additional suitable dyes include Direct Blue 86(Miles), Fastusol Blue (Mobay Chemical Corp.), Acid orange 7 (American Cyanamid), Basic Vilet 10(Sandoz), Acid Yellow 23 (GAF), Acid Yellow 17 (Sigma chemical), Sap Green (Keyston Analine and Chemical), Metanil Yellow (Keystone Analine and Chemical), Acid Blue 9(Hilton Davis), Sandolan Blue/Acid Blue 182 (Sandoz), Hisol Fast Red (Capitol Color and Chemical), Fluorescein (Capitol Color and Chemical), Acid Green 25 (Ciba-Geigy), Pylakor Acid Bright Red (Pylam), and the like. Fragrances or perfumes that may be included in the composition include, for example, terpenoids such as citronellol, aldehydes such as amyl cinnamaldehyde, a jasmine such as C1S-jasmine or jasmal, vanillin, and the like.
Adjuvants:
In accordance with the presently claimed invention, the cleaning composition can also include any number of adjuvants. Specifically, the composition can include stabilizing agents, wetting agents, thickeners, foaming agents, corrosion inhibitors, biocides, hydrogen peroxide, pigments or dyes among any number of other constituents which can be added to the composition. Such adjuvants can be performulated with the present composition or added to the system simultaneously,

or even after, the addition of the present composition. The composition can also contain any number of other constituents as necessitated by the application, which are known and which can facilitate the activity of the present compositions.
Chelant:
The composition provided and to be prepared as described in context with the presently claimed invention may optionally further comprise a chelant at a level of from 0.1% to 10%, preferably from 0.2% to 5%, more preferably from 0.2% to 3% by weight of the composition.
As commonly understood a chelant is used either to soften the process water or it is used to assist in dissolution of scales caused due to hard water. Chelation herein means the binding or complexation of a bi- or multi-dentate ligand. These ligands, which are often organic compounds, are called chelants, chelators, chelating agents, and/or sequestering agent. Chelating agents form multiple bonds with a single metal ion. Chelants, are chemicals that form soluble, complex molecules with certain metal ions, inactivating the ions so that they cannot normally react with other elements or ions to produce precipitates or scale, or destabilizing soils facilitating their removal accordingly. The ligand forms a chelate complex with the substrate. The term is reserved for complexes in which the metal ion is bound to two or more atoms of the chelant.
Suitable chelating agents can be selected from the group consisting of alkali metal citrate, gluconate based sequestrants, EDTA, NTA, MGDA, GLDA, ED3A, gluconates, phosphates, alkali metal phosphates, alkali metal carbonates, amino carboxylates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures thereof.
Amino carboxylates include ethylenediaminetetra-acetates, N-hydroxyethylethylene diamine triacetates, nitrilo-triacetates, ethylenediamine tetraproprionates, triethylene tetraamine hexacetates, diethylene triamine pentaacetates, and ethanoldiglycines, alkali metal, ammonium, and substituted ammonium salts therein and mixtures therein, as well as MGDA (methyl-glycine-diacetic acid), and salts and derivatives thereof and GLDA (glutamic-N,N- diacetic acid) and salts and derivatives thereof. GLDA (salts and derivatives thereof) is especially preferred according to the invention, with the tetrasodium salt thereof being especially preferred.
Other suitable chelants include amino acid based compound or a succinate based compound. The term "succinate based compound" and "succinic acid based compound" are used interchangeably herein. Other suitable chelants are described

in USP 6,426,229. Particular suitable chelants include; for example, aspartic acid-N-monoacetic acid (ASMA), aspartic acid-N,N-diacetic acid (ASDA), aspartic acid-N-monopropionic acid (ASMP), iminodisuccinic acid (IDS), Imino diacetic acid (IDA), N- (2-sulfomethyl) aspartic acid (SMAS), N- (2-sulfoethyl) aspartic acid (SEAS), N-(2- sulfomethyl) glutamic acid (SMGL), N- (2- sulfoethyl) glutamic acid (SEGL), N-methyliminodiacetic acid (MIDA), alanine-N,N-diacetic acid (ALDA), serine-N,N-diaceticacid (SEDA), isoserine-N,N-diacetic acid (ISDA), phenylalanine-N,N-diacetic acid (PHDA), anthranilic acid- N ,N - diacetic acid (ANDA), sulfanilic acid-N, N-diacetic acid (SLDA), taurine-N, N-diacetic acid (TUDA) and sulfomethyl-N,N-diacetic acid (SMDA) and alkali metal salts or ammonium salts thereof. Also suitable is ethylenediamine disuccinate ("EDDS"), especially the [S,S] isomer as described in U.S. Patent 4,704,233. Furthermore, hydroxyethyleneiminodiaceticacid, hydroxyiminodisuccinic acid, hydroxyethylene diaminetriacetic acid are also suitable.
Other chelants include homopolymers and copolymers of polycarboxylic acids and their partially or completely neutralized salts, monomeric polycarboxylic acids and hydroxycarboxylic acids and their salts. Preferred salts of the abovementioned compounds are the ammonium and/or alkali metal salts, i.e. the lithium, sodium, and potassium salts, and particularly preferred salts are the sodium salts.
Suitable polycarboxylic acids comprise acyclic, alicyclic, heterocyclic and aromatic carboxylic acids, in which case they contain at least two carboxyl groups which are in each case separated from one another by, preferably, no more than two carbon atoms. Polycarboxylates which comprise two carboxyl groups include, for example, water-soluble salts of, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartaric acid and fumaric acid. Polycarboxylates which contain three carboxyl groups include, for example, water-soluble citrate. Correspondingly, a suitable hydroxycarboxylic acid is, for example, citric acid. Another suitable polycarboxylic acid is the homopolymer of acrylic acid. Preferred are the polycarboxylates end capped with sulfonates.
Amino phosphonates may also be suitable for use as chelating agents and include ethylenediaminetetrakis (methylenephosphonates) as DEQUEST. Preferred are these amino phosphonates that do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.
Polyfunctionally-substituted aromatic chelating agents may also be useful in the compositions herein such as described in U.S. Patent 3,812,044. Preferred compounds of this type are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.

Further suitable polycarboxylates chelants for use herein include citric acid, lactic acid, acetic acid, succinic acid, formic acid; all preferably in the form of a water-soluble salt. Other suitable polycarboxylates are oxodisuccinates, carboxymethyloxysuccinate and mixtures of tartrate monosuccinic and tartrate disuccinic acid such as described in US 4,663,071.
The most preferred chelants for use in the presently claimed invention are selected from the group consisting of diethylenetetraamine pentaacetic acid (DTPA), EDTA, NTA, MGDA, GLDA, ED3A, Gluconates, Phosphates and mixtures thereof.
Preservatives:
The composition provided and to be prepared as described in context with the presently claimed invention optionally may further comprise a preservative. A preservative is a naturally occurring or synthetically produced substance that is added to cleaning compositions to prevent decomposition by microbial growth or by undesirable chemical changes. Preservatives can be divided into two types, depending on their origin. Class I preservatives refers to those preservatives which are naturally occurring, everyday substances. Class II preservatives refer to preservatives which are synthetically manufactured. Most preferred preservatives for use in liquid cleaning compositions include derivatives of isothiazolinones, including methylisothiazolinone, methylchloroisothiazolinone, octylisothiazolinone, 1,2-benzisothiazolinone, and mixtures thereof. Other non-limiting examples of preservatives typically used are phenoxyethanol, paraben derivatives such as methyl paraben and propyl paraben, imidazole derivatives, and aldehydes including glutaraldehyde.
The cleaning composition provided and to be prepared as described in context with the presently claimed invention may comprise a number of optional ingredients such as builders, conditioning polymers, cleaning polymers, surface modifying polymers, soil flocculating polymers, structurants, emollients, humectants, skin rejuvenating actives, enzymes, carboxylic acids, scrubbing particles, bleach and bleach activators, perfumes, malodor control agents, pigments, dyes, opacifiers, beads, pearlescent particles, microcapsules, antibacterial agents, enzymes and pH adjusters and buffering means or water or any other dilutents or solvents compatible with the formulation.

Examples:
1. Composition of the formula and process of manufacture
The removal of stain from a hard surface using the composition according to the invention was evaluated. As it can be seen from the results below, composition (F1) comprising methanesulfonic acid of the invention provide considerably greater stain removal than grease removal than the similar composition (F2) comprising hydrochloric acid instead of methanesulfonic acid.
Example 1
Two hard surface cleaning compositions (test formulations) were made as, F1 with the methanesulfonic acid according to the presently claimed invention and F2 with hydrochloric acid, as shown in Table 1 below:
Table 1: Ingredients of test formulations F1 and F2

F1 F2
Components Quantity (Wt-%) Components Quantity (Wt-%)
methanesulfonic acid [Lutropur® M (70%)] 4 hydrochloric acid (35%) 32
surfactant (Lutensol® TO 8) 1 surfactant (Ethomeen® 0/12) 3
xanthan gum (Kelzan® ASX-T) 0.5 - -
water Up to 100 water Up to 100
Total 100 Wt-% Total 100 Wt-%
Lutropur® M is high purity methanesulfonic acid 70% (in water), available from BASF SE, Ludwigshafen, Germany
Lutensol® TO 8 is a C13-OXO alcohol ethoxylate, available from BASF SE, Ludwigshafen, Germany
Kelzan® ASX-T is xanthan gum available, from CP Kelco, USA
Ethomeen® 0/12 is an oleyl amine ethoxylate, available from AkzoNobel, The Netherlands

A. Preparation of test Formulation F1:
Steps to prepare the F1:
a) Charged 80% of total process water into the reactor;
b) Prepared a premix of the Lutensol® TO with xanthan gum;
c) Slowly added this premix into the reactor under stirring;
d) Prepared a mixture of the Lutropur® M with the balance process water;
e) Added this mixture of step d) to the addition product of step c) under stirring and continued the stirring to get a uniform and viscous cleaning composition.
A1: Steps to prepare test formulation F2: Steps to prepare the F2:
a) water was charged to reactor;
b) Added the hydrochloric acid into the reactor under stirring;
c) Added the Ethomeen® 0/12 under stirring; and
d) Stirred well to get a uniform viscous product.
B. Calcium stearate stain formation process (as per IKW Drop Test Procedure):
Stepwise preparation of an aqueous dispersion of calcium stearate:
a) 5% calcium stearate was mixed with 89% ethanol and 8% water;
b) Stirred this mixture well to homogenize it into a fine dispersion. Continued stirring for one day (magnetic blade stirring);
c) Gradually and homogeneously applied this mixture onto the test ceramic tile;
d) Fixed quantity of soil solution applied to ensure repeatability of the test;
e) Allowed this applied solution to dry at ambient conditions, a white waxy layer was formed;
f) Heated this tile at 180 degrees for 1 hour and allowed it to cool. During this phase, the stearate layer was melt to produce a uniform layer of calcium stearate scale.
Application of the test formulations:
Applied drop wise the test formulation of F1 and F2 separately to surfaces of the ready stains of B. Quantity of the test formulations F1 and F2 used was 1 gram in both experiments. The cleaning efficacy of the test formulations F1 and F2 was determined by rinsing the tile after fixed intervals 30 seconds and 60 seconds.

Results:
Table 2: Test results of test formulations F1 and F2 on 2mm thick stain

Test formulation Thickness of stain layer Time of contact Stain removal efficiency (visual evaluation)
F1 2 mm 30 seconds All the scale under contact area was removed. Clear visible ceramic surface.
F1 2 mm 60 seconds All the scale under contact area was removed. Clear visible ceramic surface.
F2 2 mm 30 seconds Incomplete scale removal, whitish layer observed still under formula contact area.
F2 2 mm 60 seconds All the scale under contact area was removed. Clear visible ceramic surface.
Example 2:
Formulation procedure and details:
Following set of 6 formulations were prepared, process conditions were kept identical for each batch. Raw materials used were from same batch throughout the experiment.
Table 3: Formulation 1 to 6 comprising ingredients in %

Ingredients
(wt-%) Formul¬ation 1 Formul-ation 2 Formul¬ation 3 Formul¬ation 4 Formul¬ation 5 Formul-ation 6
surfactant 1.0 1.0 1.0 1.0 1.0 1.0
xanthan gum 0.1 0.5 0.7 1.0 2 4
70% methanesulfoni c acid in water 4.0 4.0 4.0 4.0 4.0 4.0
water up to 100% up to 100% up to 100% up to 100% up to 100% up to 100%
Total 100% 100% 100% 100% 100% 100%

Above batches of 350gm size prepared by procedure comprising below steps:
a) Charge 60% of process water in the reactor;
b) Prepare premix of surfactant along with xanthan gum;
c) Charge this premix into the reactor under stirring for 30 minutes;
d) Prepare premix of methanesulfonic acid 70% with balance 40% process water; and
e) Stirred for 15 minutes and then discharge the batch;
The above batches then allowed standing for one day at ambient temperature to acclimatize to room conditions. After that, the scale dissolution test was conducted the following day. The results from the scale dissolution tests were as follows.
Scale dissolution tests:
Marble blocks were used for below experiments. Marble results from the metamorphism of sedimentary dolomite or limestone rock. The marble block here is used to represent the Calcium scale. These marble blocks cut identically into pieces of 3x3 inch to create uniform test conditions. Further, when the blocks selected, they are from the same stone sheet so as to keep the chemical composition of scale as identical as possible. The test using the Marble blocks is motivated based on the test procedure suggested by IKW Germany where the standard marble block of one 'Carrara' grade is used.
The tests conducted in the following steps:
1) 3X3 inch marble blocks are washed clean with de-ionized water, dried at 100°C and weighed;
2) Equal amount of cleaning formulations 1 to 6 kept in different 500 ml glass beakers;
3) Added one marble block into each beaker slowly without splashing and marble blocks were fully immersed in cleaning formulations;
4) Continued the immersion for a period of 30 minutes without disturbing;
5) Removed marble blocks from each beaker after 30 minutes and cleaned with water without any scrubbing or mechanical abrasion;
6) Blocks were rinsed and then dried at 100°C for 1 hr.;
7) After drying, allowed blocks to acclimatize to room temperature and then weighed them.

Test Results:
Amount of scale removed = (weight of block before immersion) - (weight of block after immersion)

Formulation No. 1 2 3 4 5 6
Original Weight of marble block before test (in gm) 235.5 292.7 233.5 235.6 239.9 293.6
Weight of marble block after test (in
gm) 232.6 289.1 231.0 233.3 239.8 293.5
Difference in the weight of the marble block before and after test (in gm) 2.9 3.6 2.5 2.3 0.1 0.1
From the above data, it is clear that the difference in weights of marble blocks before and after application test is different for the six formulations. This mass loss is highest for formulation 2. The mass loss seen with the marble block corresponds to the cleaning efficiency of the formulation, as the mass loss caused by the carbonate scale dissolution. Higher the loss in mass of the marble block better is the scale dissolution and subsequently, the product expected to be provide better cleaning during application. Conversely, less mass loss of the marble block after testing indicates lesser cleaning efficiency of the formulation.

CLAIMS

1. A cleaning composition comprising:
a) ≥ 1 to ≤ 20 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.5 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 10 wt-% of at least one surfactant;
d) ≥ 80 to ≤ 98 wt-% of at least one solvent; and
e) ≥ 0.0 to ≤ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
2. The cleaning composition according to claim 1, wherein the cleaning composition comprises ≥ 2 to ≥ 10 wt-% of methanesulfonic acid.
3. The cleaning composition according to claim 1 or 2, wherein the cleaning composition comprises ≥ 0.1 to ≤ 1.0 wt-% of xanthan gum.
4. The cleaning composition according to one or more of claims 1 to 3, wherein the cleaning composition comprises ≥ 0.1 to ≤ 5 wt-% of at least one surfactant.
5. The cleaning composition according to one or more of claims 1 to 4, wherein the cleaning composition comprises ≥ 90 to ≤ 98 wt- % of at least one solvent.
6. The cleaning composition according to one or more of claims 1 to 5, wherein the at least one surfactant is selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants.
7. The cleaning composition according to one or more of claims 1 to 6, wherein the at least one solvent is selected from the group consisting of water, isopropyl alcohol, propylene glycol, sorbitol, polyethylene glycol, glycerol, polypropylene glycol and ethanol.
8. The cleaning composition according to one or more of claims 1 to 7, wherein the at least one additive is selected from the group consisting of colorants, fragrances, adjuvants, chelants and antimicrobial and/or biocidal substances.

9. The cleaning composition according to claim 1 comprising:
a) ≥ 1 to ≤ 10 wt-% of methanesulfonic acid;
b) ≥ 0.1 to ≤ 1.0 wt-% of xanthan gum;
c) ≥ 0.1 to ≤ 5 wt-% of at least one surfactant selected from the group consisting of nonionic, anionic, cationic, zwitterionic, and amphoteric surfactants;
d) ≥ 90 to ≤ 98 wt-% of at least one solvent selected from the group consisting of water, isopropyl alcohol, propylene glycol, sorbitol, polyethylene glycol, glycerol, polypropylene glycol and ethanol; and
e) ≥ 0.0 to ≤ 10 wt-% of at least one additive;
whereby the sum of the weight percentages of the components a), b), c), d) and e) adds up to 100 wt-%.
10. A method of cleaning a hard surface comprising the steps of:
- applying the cleaning composition according to one or more of claim 1 to 9 to the hard surface; and - rinsing the hard surface. -