Field of the invention

The present invention relates to detergent compositions and their use to reduce spotting on dishware treated in a machine dishwasher.

Background of the invention

Detergent compositions typically contain a number of different active components, including builders, surfactants, enzymes and bleaching agents.

Surfactants are employed to remove stains and soil and to disperse the released components into the cleaning liquid. Enzymes help to remove stubborn stains of proteins, starch and lipids by hydrolyzing these components. Bleach is used to remove stains by oxidizing the components that make up these stains.

Calcium and magnesium ions in the wash liquor can have a negative effect on the removal of stains/soils by detergent compositions. In order to reduce the negative effects of such ions so called 'builders' (complexing agents) are commonly applied in detergent compositions. Phosphorous based builders have been used for many years in a wide variety of detergent compositions. Some of these phosphorus based builders, such as trisodium phosphate and sodium tripolyphospate (STPP), have set a benchmark in the dishwasher detergent industry as having excellent performance when it comes to reducing spotting and filming of dishware, such as glassware. As such, phosphorus- containing builder components are generally considered to be "high- performance" builders. As builder they are often present in relatively high amounts in the detergent composition. For example sodium tripolyphosphate levels of 20 - 50 % are typical for phosphorous based build detergents. High levels of phosphorous based builders in detergent compositions is nowadays seen as undesirable. The use of phosphorous based builders in detergent compositions has led to environmental problems such as eutrophication. To curtail such problems many jurisdictions have, or are in the process of, issuing laws and regulations to restrict the maximum amount of phosphorous in detergent compositions. As such there has been a need for more environmentally friendly alternative builders, which have on-par effectiveness and are also cost-effective. Examples of alternative builders are alkali carbonates, glutamic- Ν,Ν-diacetate (GLDA), methyl-glycine diacetate (MGDA) and citrate. In particular alkali carbonates are widely used as low-cost builder in detergent compositions. The additional benefit of alkali carbonate builders is that they provide efficient buffering of the wash liquor. However, the use of alkali carbonates as builder generally means they are present in a relatively high amounts which presents certain problems. Carbonate builders having scavenged calcium and/or magnesium ions from the wash liquor tend to precipitate. This in turn can cause scale formation and spotting and is particularly problematic for machine dishwashing applications of the detergent composition as scale and spotting is readily visible on dishware after machine dish wash treatment. The main causes of spotting in machine dish washing are incomplete wetting during the main wash-stage and the presence of soil-containing (e.g. calcium carbonate containing) droplets at the start of the drying-stage. Obviously, spots present on dishware, after completion of the machine dish wash treatment is highly undesirable as it gives an unclean impression of the dishware.

US2004/0058846 recognizes the problem of spotting of glassware when cleaned using a machine dish washer and mentions that such spots can be removed by further manual cleaning using a dishcloth. This solution is clearly not satisfactory as involving a further cleaning step and requiring further effort from the consumer.

It is an object of the present invention to provide a detergent composition comprising alkali carbonates (at levels of 20 to 80 wt. %), which when used as detergent in a machine dishwasher, results in less spotting on the treated dishware, while at the same time providing good cleaning and shine of the dishware as well as causing little or no filming and corrosion of the dishware. Spotting on glass and metal surfaces is particularly undesirable. These tend to be smooth surfaces (e.g. as compared to wooden articles). Also glass surfaces are often appreciated for their transparent nature, while metal surfaces are often appreciated for their high reflective, even mirror-like properties. Spotting on glass and/or metal surfaces thus not only provides the items with an unclean impression, but also can negatively affect the particular qualities for which such surface are generally

appreciated. It is another object of the present invention to provide a detergent composition comprising alkali carbonates (at levels of 20 to 80 wt. %), which when used as detergent in a machine dishwasher, results in less spotting on treated metal and/or glass surfaces, while at the same time providing good cleaning and shine of the surfaces as well as causing little or no filming and corrosion of the surfaces.

Summary of the invention

One or more of the above objects are achieved by a detergent composition comprising:

• from 20 to 80 wt. % of alkali carbonate; and

• from 1.0 to 10 wt. % of nonionic surfactant; and

· from 1.0 to 10 wt.% of copolymer comprising:

i. monomers containing sulfonic acid groups;

ii. further ionic and/or nonionic monomers; and

• from 0.1 to 9.0 wt. % of a mixture of:

a) phosphonates, phosphonic acids or a combination thereof; and b) phosphates, phosphoric acids or a combination thereof.

It was surprisingly found that the use of the detergent composition according to the invention in machine dish wash provided effective cleaning (also providing good shine and little or no filming and corrosion) of dishware with little or no spotting. It was particularly effective in reducing the amount of spotting on treated glass and metal surfaces. More surprisingly the use of 0.1 to 9.0 wt. % of the mixture of a) and b) acts synergistically in the detergent composition according to the invention to reduce the spotting when compared to the use of a) or b) alone. In general these findings are the more surprising since the total amount of phosphonates, phosphonic acids, phosphates and phosphoric acids is far below typical builder levels. Detailed description

Definitions

Weight percentage (wt. %) is based on the total weight of the composition unless otherwise stated. It will be appreciated that the total weight amount of ingredients will not exceed 100 wt. % based on total weight of the composition. Whenever an amount or concentration of a component is quantified herein, unless indicated otherwise, the quantified amount or quantified concentration relates to said component per se, even though it may be common practice to add such a component in the form of a solution or of a blend with one or more other ingredients. It is furthermore to be understood that the verb "to comprise" and its conjugations is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. Finally, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

Alkali carbonate

The use of alkali carbonate is known in the field of detergent making. In particular alkali carbonate is appreciated in view of its double-function as builder and buffer. The detergent composition according to the invention comprises from 20 to 80 wt.% of alkali carbonate. The preferred amount of alkali carbonate is from 30 to 75 wt.%, more preferably from 35 to 70 wt.% and even more preferably from 40 to 65 wt.%. Such levels of alkali carbonate provide good Ca ²⁺ and Mg ²⁺ ion scavenging for most types of water hardness levels, as well as other builder effects, such as providing good buffering capacity. The preferred alkali carbonates are sodium- and/or potassium carbonate of which sodium carbonate is particularly preferred. It is further preferred that sodium carbonate makes up at least 75 wt. %, more preferably at least 85 wt. % and even more preferably at least 90 wt. % of the total weight of the alkali carbonate. The alkali carbonate present in the composition according to the invention can be present as such or as part of a more complex ingredient (e.g. sodium carbonate in sodium percarbonate). The determination of the total amount of alkali carbonate takes into account the amount of alkali carbonate added as such, as well as added as part of more complex ingredients.

Further builders

The composition according to the invention may comprise further builders, besides alkali carbonates.

Further builders which can be used in the detergent composition according to the invention can be non-aminocarboxylate polycarboxylic acid builders and/or their salts. Examples of preferred non-aminocarboxylic acid builders are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, maleic acid, fumaric acid, saccharic acids, their salts, or mixtures thereof. Of these, particularly preferred are citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid, their salts, or mixtures thereof. Citric acid and/or citrate are particularly beneficial as they, besides acting as builder, are also highly biodegradable, and were found to further reduce spotting on machine- dishwasher treated dishware. As such more preferably the detergent composition according to the invention comprises citric acid, citrate salt or mixtures thereof. In general salts are more preferred than acid forms of these non-aminocarboxylate builders, and particularly preferred are the sodium and/or potassium salts. If present the total amount of citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, maleic acid, fumaric acid, saccharic acids and salts thereof, wherein the weight of the salts is based on the acid equivalent, preferably is from 3 to 35 wt. %, more preferably from 7 to 30 wt. % and even more preferably from 10 to 25 wt. %. Other examples of preferred further builders also include aminocarboxylates. These are well known in the detergent industry and sometimes referred to as

aminocarboxylate chelants. Aminocarboxylates are beneficial as these are in general strong builders. Examples of preferred aminocarboxylates are glutamic acid N,N- diacetic acid (GLDA), methylglycinediacetic acid (MGDA), iminodisuccinic acid (IDS), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethyliminodiacetic acid (HEIDA), Nitrilotriacetic acid (NTA) , aspartic acid diethoxysuccinic acid (AES) , aspartic acid-N,N-diacetic acid (ASDA), hydroxyethylene- diaminetetraacetic acid (HEDTA), hydroxyethylethylenediaminetriacetic acid (HEEDTA), iminodifumaric (IDF), iminoditartaric acid (IDT), iminodimaleic acid

(IDMAL), iminodimalic acid (IDM), ethylenediaminedifumaric acid (EDDF),

ethylenediaminedimalic acid (EDDM), ethylenediamineditartaric acid (EDDT), ethylenediaminedisuccinic acid (EDDS), ethylenediaminedimaleic acid and (EDDMAL), dipicolinic acid, their salts, and combinations thereof. In general the salts of

aminocarboxylates are more preferred than the acid forms, and particularly preferred are sodium and/or potassium salts. More preferred are GLDA, MGDA, IDS, HEIDA, EDDS, NTA or mixtures thereof. Even more preferred are GLDA, MGDA, IDS or mixtures thereof. MGDA is particularly preferred. If present the amount of

aminocarboxylate preferably is from 5 to 60 wt. %, more preferably from 10 to 40 wt. %.

Preferably the detergent composition according to the invention comprises the following combination of builders:

• from 20 to 80 wt. % of alkali carbonate; and

· from 3 to 35 wt. % of a total amount of citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid, their salts or mixtures thereof, wherein the weight of the salts is based on the acid equivalent; and/or

• aminocarboxylate in a total amount of 5 to 60 wt. %. As mentioned aminocarboxylates are strong builders. Preferably if the total amount of GLDA and MGDA is from 10 to 40 wt. %, the preferred amount of alkali carbonate is from 30 to 50 wt. %.

Particularly preferred are detergent composition according to the invention comprising the following combination of builders:

• from 20 to 75 wt. % of alkali carbonate; and

• from 7 to 30 wt. % of citric acid, citrate or a mixture thereof, wherein the weight of the citrate is based on the acid equivalent. Mixture of a) and b)

The composition according to the invention comprises from 0.1 to 9.0 wt. % of a mixture of a) phosphonates, phosphonic acids or a combination thereof; and b) phosphates, phosphoric acids or a combination thereof. This means that the composition according to the invention will comprises one or more of the following combinations: phosphonates + phosphates; phosphonates + phosphoric acids;

phosphonic acids + phosphates; or phosphonic acids + phosphoric acids. With

'comprising from 0.1 to 9.0 wt. % of a mixture of a) and b)' is meant that the total amount of a) + b) is from 0.1 to 9.0 wt. %. The composition according to the invention preferably comprises from 0.2 to 9.0 wt. %, from 0.3 to 9.0 wt. %, from 0.4 to 9.0 wt. % or 0.5 to 9.0 wt. % of the mixture of a) and b). Further preferred amounts are from 0.6 to 8.0 wt. %, more preferably from 1.0 to 7.0 wt. % and even more preferably from 2.0 to 6.0 wt. % of a mixture of a) and b). These preferred amounts of the mixture of a) and b) on the one hand provide excellent results, whilst keeping the total phosphorous load low. Both the terms phosphonic acids and phosphoric acids include their partially neutralized acids.

The preferred total weight amount of a) the phosphonates and phosphonic acids, is from 0.5 to 6.0 wt. %, more preferably from 0.75 to 4.0 wt. % and even more preferably from 1.0 to 3.0 wt. %. Preferred phosphonates and phosphonic acids are complex- forming phosphonates/phosphonic acids, of which particularly preferred are 1- hydroxyethane-1 ,1 -diphosphonic acid (HEDP), diethylenetriamine-penta

(methylenephosphonic acid) (DTPMP), ethylenediaminetetra-methylenephosphonate (EDTMP) or mixtures thereof. These may include their higher homologues. They are preferably used in the form of the sodium salts which exhibit a neutral reaction, for example as the hexasodium salt of EDTMP or as the hepta- and octasodium salt of DTPMP. Further preferred are DTPMP and/or HEDP of which HEDP is even more preferred. Particularly preferred is that at least 50 wt. %, more preferably at least 75 wt. % and even more preferably at least 90 wt. % of the total weight amount of a) is HEDP, DTPMP, EDTMP or a mixture thereof.

The preferred total weight amount of b) the phosphates and phosphoric acids, is from 0.05 to 5.0 wt. %, more preferably from 0.2 to 3.0 wt. % and even more preferably from 0.5 to 2.0 wt. %. Of particular preference are alkali salts of tripolyphosphate, pyrophosphate or a mixture thereof of which sodium tripolyphosphate (STPP) is even more preferred. Preferably at least 50 wt. %, more preferably at least 75 wt. % and even more preferably at least 90 wt. % of the total weight amount of b) are alkali salts of tripolyphosphate, pyrophosphate or a mixture thereof.

Particular good results are achieved with certain weight ratios of a) and b) in the composition according to the invention. As such preferred are detergent compositions according to the invention wherein the ratio of the total weight amount of a) the phosphonates and phosphonic acids to the total weight amount of b) the phosphates and phosphoric acids, is from 0.2:1 to 10:1 , more preferably from 0.5:1 to 8:1 , even more preferably from 1 :1 to 5:1 , still even more preferably from 1 .5:1 to 4:1 and still even more preferably form 1.6:1 to 3:1.

Even better results were obtained with certain species combinations of a) and b). As such the composition according to the invention preferably comprises from 0.6 to 8.0 wt. % of a mixture of

a) HEDP in an amount of from 0.5 to 6.0 wt. %; and

b) alkali tripolyphosphate in an amount of 0.05 to 5.0 wt. %,

wherein the weight ratio between a) and b) preferably is from 0.5:1 to 8:1 .

Copolymer

The composition according to the invention comprises from 1.0 to 10 wt. % of copolymer comprising i) monomers containing sulfonic acid groups and ii) further ionic and/or nonionic monomers. The use of such copolymers in the detergent composition according to the invention was found to further reduce spotting of dishware upon treatment in a dishwasher. The amount of copolymer used in the composition according to the invention preferably is from 1.5 to 8.0 wt. %, more preferably from 2.0 to 5.0 wt. % and even more preferably from 2.5 to 4.0 wt. %.

The copolymer may comprise two, three, four or more different monomer units.

Preferred monomers containing sulfonic acid groups are those of the formula

R ⁵ (R ⁶ )C=C(R ⁷ )-X-S0 ₃ H in which R ⁵ to R ⁷ mutually independently denote -H, -CH3, a straight-chain or branched saturated alkyl residue with 2 to 12 carbon atoms, a straight-chain or branched, mono- or polyunsaturated alkenyl residue with 2 to 12 carbon atoms, alkyl or alkenyl residues substituted with -NH ₂ , -OH or -COOH, or denote -COOH or -COOR ⁴ , R ⁴ being a saturated or unsaturated, straight-chain or branched hydrocarbon residue with 1 to 12 carbon atoms, and X denotes an optionally present spacer group which is selected from -(CH ₂ ) _n - with n = 0 to 4, -COO-(CH ₂ ) _k - with k = 1 to 6, -C(0)-NH-C(CH ₃ ) ₂ - and -C(0)-NH-CH(CH ₂ CH ₃ )-. Preferred among these monomers are those of the formulae

H ₂ C=CH-X-S0 ₃ H

H ₂ C=C(CH ₃ )-X-S0 ₃ H

H0 ₃ S-X-(R ⁶ )C=C(R ⁷ )-X-S0 ₃ H, in which R ⁶ and R ⁷ are mutually independently selected from -H, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₃ , -CH(CH ₃ ) ₂ and X denotes an optionally present spacer group which is selected from -(CH ₂ ) _n - with n = 0 to 4, -COO-(CH ₂ ) _k - with k = 1 to 6, -C(0)-NH- C(CH ₃ ) ₂ - and -C(0)-NH-CH(CH ₂ CH ₃ )-.

Particularly preferred monomers containing at least one sulfonic acid group are 1- acrylamido-1 -propanesulfonic acid, 2-acrylamido-2-propanesulfonic acid, 2-acrylamido-

2- methyl-1 -propanesulfonic acid, 2-methacrylamido-2-methyl-1-propanesulfonic acid,

3- methacrylamido-2-hydroxypropanesulfonic acid, allylsulfonic acid, methallylsulfonic acid, allyloxybenzenesulfonic acid, methallyloxybenzenesulfonic acid, 2-hydroxy-3-(2- propenyloxy)propanesulfonic acid, 2-methyl-2-propene-1 -sulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropylmethacrylate,

sulfomethacrylamide, sulfomethylmethacrylamide or mixtures thereof. Water-soluble salts of these acids are equally well preferred as well as mixtures of the salts and mixtures the salts and the acids.

The sulfonic acid groups may be present in the polymers entirely or in part in neutralized form, i.e. the acidic hydrogen atom of the sulfonic acid group may be replaced in some or all of the sulfonic acid groups with metal ions, preferably alkali metal ions and in particular with sodium ions. It is preferred according to the invention to use copolymers containing partially or completely neutralized sulfonic acid groups. In those copolymers solely containing monomers from groups i. and ii., the monomer distribution preferably amounts in each case from 5 to 95 wt. % of i. or ii., particularly preferably from 50 to 90 wt.% of monomer from group i. and from 10 to 50 wt.% of monomer from group ii., in each case relative to the copolymer. The molar mass of the sulfo copolymers preferably used according to the invention may be varied in order to tailor the properties of the polymers to the desired intended application. Preferred automatic dishwashing agents are characterized in that the copolymers have molar masses of 2000 to 200.000 gmol ^"1 , preferably of 4000 to 25.000 gmol ^"1 and in particular of 5000 to 15.000 gmol ^"1 .

The copolymer according to the invention further comprises ionic and/or nonionic monomers. Preferred ionic monomers are unsaturated carboxylic acids. Preferred unsaturated carboxylic acids are those of the formula R ¹ (R ² )C=C(R ³ )COOH, in which R ¹ to R ³ mutually independently denote -H, -CH3, a straight-chain or branched saturated alkyl residue with 2 to 12 carbon atoms, a straight-chain or branched, mono- or polyunsaturated alkenyl residue with 2 to 12 carbon atoms, alkyl or alkenyl residues substituted with -NH ₂ , -OH or -COOH as defined above or denote -COOH or -COOR ⁴ , R ⁴ being a saturated or unsaturated, straight-chain or branched hydrocarbon residue with 1 to 12 carbon atoms.

Preferred monomers containing carboxyl groups are acrylic acid, methacrylic acid, ethacrylic acid, chloroacrylic acid, cyanoacrylic acid, crotonic acid, phenylacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid,

methylenemalonic acid, sorbic acid, cinnamic acid or mixtures thereof.

Preferred nonionic monomers are those of the general formula

R ¹ (R ² )C=C(R ³ )-X-R ⁴ , in which R ¹ to R ⁴ mutually independently denote -H, -CH ₃ , or -C2H5, X denotes an optionally present spacer group which is selected from -CH2-, -C(0)0- and -C(0)-NH-, and R ⁴ denotes a straight-chain or branched saturated alkyl residue with 2 to 22 carbon atoms or denotes an unsaturated, preferably aromatic residue with 6 to 22 carbon atoms. More preferred nonionic monomers are butene, isobutene, pentene, 3-methylbutene, 2- methylbutene, cyclopentene, hexene, 1-hexene, 2-methyl-1 -pentene, 3-methyl-1 - pentene, cyclohexene, methylcyclopentene, cycloheptene, methylcyclohexene, 2,4,4- trimethyl-1 -pentene, 2,4,4-trimethyl-2-pentene, 2, 3-dimethyl-1 -hexene, 2,4-dimethyl-1 - hexene, 2, 5-dimethyl-1 -hexene, 3,5-dimethyl-1-hexene, 4,4-dimethyl-1 -hexane, ethylcyclohexyne, 1 -octene, -olefins with 10 or more carbon atoms such as for example 1 -decene, 1 -dodecene, 1 -hexadecene, 1-octadecene and C22-1 -olefin, 2-styrene, - methylstyrene, 3-methylstyrene, 4-propylstryene, 4-cyclohexylstyrene, 4- dodecylstyrene, 2-ethyl-4-benzylstyrene, 1 -vinylnaphthalene, 2-vinylnaphthalene, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, methyl methacrylate, N-(methyl)acrylamide, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, N-(2-ethylhexyl)acrylamide, octyl acrylate, octyl methacrylate. N- (octyl)acrylamide, lauryl acrylate, lauryl methacrylate, N-(lauryl)acrylamide, stearyl acrylate, stearyl methacrylate, N-(stearyl)acrylamide, behenylacylate, behenyl methacrylate and N-(behenyl)acrylamide or mixtures thereof.

Nonionic surfactant

The composition according to the invention comprises from 1.0 to 10 wt. % of nonionic surfactant. The preferred total amount of nonionic surfactants is from 2.0 to 8 wt. % and more preferred is an amount of from 2.5 to 5.0 wt.%. The nonionic surfactant used in the composition according to the invention can be a single nonionic surfactant or a mixture of two or more non-ionic surfactants.

Nonionic surfactants of the amine oxide type, for example N-coconut alkyl-N, N- dimethylamine oxide and N-tallow alcohol-N, N-dihydroxymethylamine oxide, and of the fatty acid alkanolamide type may also be suitable. The quantity of these nonionic surfactants preferably amounts to no more than that of the ethoxylated fatty alcohols, in particular no more than half the quantity thereof. A further class of preferred nonionic surfactants, which may be used either as sole nonionic surfactant or in combination with other nonionic surfactants, are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated fatty acid alkyl esters, preferably with 1 to 4 carbon atoms in the alkyl chain.

Low-foaming nonionic surfactants are used as preferred surfactants. Detergent compositions, in particular for machine dishwashing, particularly preferentially contain nonionic surfactants from the group of alkoxylated alcohols. Alkoxylated,

advantageously ethoxylated, in particular primary alcohols with preferably 8 to 18 C atoms and on average 1 to 12 mol of ethylene oxide (EO) per mol of alcohol, in which the alcohol residue may be linear or preferably methyl-branched in position 2 or may contain linear and methyl-branched residues in the mixture, as are usually present in oxo alcohol residues, are preferably used as nonionic surfactants. In particular, however, alcohol ethoxylates with linear residues prepared from alcohols of natural origin with 12 to 18 C atoms, for example from coconut, palm, tallow fat or oleyl alcohol, and on average 2 to 8 mol of EO per mol of alcohol are preferred. The preferred ethoxylated alcohols include for example CM-U alcohols with 3 EO to 4 EO, C9-12 alcohol with 7 EO, C13-15 alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C12-18 alcohols with 3 EO, 5 EO or 7 EO and mixtures of these, such as mixtures of C12-14 alcohol with 3 EO and C12-19 alcohol with 5 EO. The stated degrees of ethoxylation are statistical averages which for a specific product may be an integer or a fractional number.

Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants fatty alcohols with more than 12 EO (ethylene oxide groups) may also be used. Examples of these are tallow fatty alcohol with 14 EO, 25 EO, 30 EO, 40 EO or 80 EO. Preferred tallow fatty alcohols with more than 12 EO have from 60 to 100 EO, and more preferably from 70 to 90 EO. Particularly preferred tallow fatty alcohols with more than 12 EO are tallow fatty alcohols with 80 EO. Nonionic surfactants from the group of alkoxylated alcohols, particularly preferably from the group of mixed alkoxylated alcohols and in particular from the group of EO-AO-EO nonionic surfactants, are likewise particularly preferentially used. The nonionic surfactant preferably comprises propylene oxide units in its molecule. Such PO units preferably constitute up to 25 wt.%, more preferably up to 20 wt.% and even more preferably up to 15 wt.% of the entire molar mass of the nonionic surfactant. Particularly preferred nonionic surfactants are ethoxylated monohydroxyalkanols or alkylphenols which additionally comprise polyoxyethylene/polyoxypropylene block copolymer units. The alcohol or alkylphenol moiety of such nonionic surfactant molecules here preferably constitutes more than 30 wt. %, more preferably more than 50 wt. % and even more preferably more than 70 wt. % of the entire molar mass of such nonionic surfactants. Preferred detergent compositions are characterized in that they contain ethoxylated and propoxylated nonionic surfactants, in which the propylene oxide units constitute in each molecule up to 25 wt. %, more preferably up to 20 wt. % and even more preferably up to 15 wt. % of the entire molar mass of the nonionic surfactant.

Preferably used surfactants originate from the groups comprising alkoxylated nonionic surfactants, in particular ethoxylated primary alcohols and mixtures of these surfactants with structurally complex surfactants such as polyoxypropylene/ polyoxyethylene/ polyoxypropylene ((PO/EO/POJ surfactants). Such (PO/EO/PO) nonionic surfactants are furthermore distinguished by good foam control. Further nonionic surfactants with melting points above room temperature which are particularly preferably to be used contain 40 to 70% of a polyoxypropylene/ polyoxyethylene/ polyoxypropylene block polymer blend, which contains 75 wt. % of a reverse block copolymer of

polyoxyethylene and polyoxypropylene with 17 mol of ethylene oxide and 44 mol of propylene oxide and 25 wt. % of a block copolymer of polyoxyethylene and

polyoxypropylene, initiated with trimethylolpropane and containing 24 mol of ethylene oxide and 99 mol of propylene oxide per mol of trimethylolpropane.

Nonionic surfactants which have proved to be particularly preferred for the purposes of the present invention are low-foaming nonionic surfactants which comprise alternating ethylene oxide and alkylene oxide units. Among these, surfactants with EO-AO-EO-AO blocks are in turn preferred, with in each case one to ten EO or AO groups being attached to one another before being followed by a block of the respective other groups. Preferred nonionic surfactants are those of the general formula R ¹ -0-(CH2-CH2-0)w-(CH2-CH-0)x-(CH2-CH2-0)y-(CH ₂ -CH-0)z-H

I I

R ² R ³ in which R ¹ denotes a straight-chain or branched, saturated or mono- or

polyunsaturated Ce-24 alkyl or alkenyl residue; each group R ² or R ³ is mutually independently selected from -CH ₃ , -CH ₂ CH ₃ , -CH2CH2-CH3, -CH(CH ₃ ) ₂ and the indices w, x, y, z mutually independently denote integers from 1 to 6.

The preferred nonionic surfactants of the above formula may be produced by known methods from the corresponding alcohols R ¹ -OH and ethylene or alkylene oxide.

Residue R ¹ in the above formula may vary depending on the origin of the alcohol. If natural sources are used, the residue R ¹ comprises an even number of carbon atoms and is generally unbranched, preference being given to linear residues from alcohols of natural origin with 12 to 18 C atoms, for example from coconut, palm, tallow fat or oleyl alcohol. Alcohols obtainable from synthetic sources are for example Guerbet alcohols or residues methyl-branched in position 2 or linear and methyl-branched residues in a mixture as are conventionally present in oxo alcohol residues. Irrespective of the nature of the alcohol used for producing nonionic surfactants contained in the preparations, preferred nonionic surfactants are those in which R ¹ in the above formula denotes an allyl residue with 6 to 24, more preferably with 8 to 20, even more preferably with 9 to 15 and still even more preferably with 9 to 1 1 carbon atoms. Apart from propylene oxide, butylene oxide may in particular be considered as the alkylene oxide unit which alternates with the ethylene oxide unit in preferred nonionic surfactants. However, further alkylene oxides, in which R ² or R ³ are mutually independently selected from -CH2CH2-CH3 or -CH(CH3)2 are also suitable. Nonionic surfactants of the above formula which are preferably used are those in which

R ² or R ³ denotes a residue -CH ³ , w and x mutually independently denote values of 3 or 4 and y and z mutually independently denote values of 1 or 2.

In summary, preferred nonionic surfactants are in particular those which comprise a C9- 15 alkyl residue with 1 to 4 ethylene oxide units, followed by 1 to 4 propylene oxide units, followed by 1 to 4 ethylene oxide units, followed by 1 to 4 propylene oxide units. In aqueous solution, these surfactants exhibit the necessary low viscosity and may particularly preferentially be used according to the invention. Surfactants of the general formula R ¹ -CH(OH)CH ₂ 0-(AO)w-(AO)x-(A'O)y-(A"O)z-R ² , in which R ¹ and R ² mutually independently denote a straight-chain or branched, saturated or mono- or polyunsaturated C2-40 alkyl or alkenyl residue; A, A, A" and A" mutually independently denote a residue from the group -CH2CH2, -CH2CH2-CH2, -CH2-H(CH3), -CH2-CH2-CH2-CH2, -CH ₂ -CH(CH ₃ )-CH ₂ -, -CH ₂ -CH(CH ₂ -CH ₃ ); and w, x, y and z denote values between 0.5 and 90, with x, y and/or z possibly also being 0, are preferred according to the invention.

In particular, preferred end group-terminated poly(oxyalkylated) nonionic surfactants are those which, according to the formula R ¹ 0[CH2CH20]xCH ₂ CH(OH)R ² , in addition to a residue R ¹ , which denotes linear or branched, saturated or unsaturated aliphatic or aromatic hydrocarbon residues with 2 to 30 carbon atoms, preferably with 4 to 22 carbon atoms, furthermore comprise a linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon residue R ² with 1 to 30 carbon atoms, x denoting values between 1 and 90, preferably values between 30 and 80 and in particular values between 30 and 60.

Particularly preferred surfactants are those of the formula

R ¹ 0[CH ₂ CH(CH3)0]x[CH2CH ₂ 0]yCH2CH(OH)R ² , in which R ¹ denotes a linear or branched aliphatic hydrocarbon residue with 4 to 18 carbon atoms or mixtures thereof. R ² denotes a linear or branched hydrocarbon residue with 2 to 26 carbon atoms or mixtures thereof and x denotes values between 0.5 and 1.5 and y denotes a value of at least 15.

Use of the above-described nonionic surfactants with a free hydroxyl group on one of the two terminal alkyl residues, can aid the formulation of film deposits in machine dishwashing. Particularly preferred end group-terminated poly(oxyalkylated) nonionic surfactants are furthermore those of the formula R ¹ 0[CH ₂ CH ₂ 0]x[CH2CH(R ³ )0]yCH2CH(OH)R ² _! in which R ¹ and R ² mutually independently denote a linear or branched, saturated or mono- or polyunsaturated hydrocarbon residue with 2 to 26 carbon atoms, R ³ is mutually independently selected from -CH ₃ , -CH ₂ CH ₃ , -CH2CH2-CH3, -CH(CH ₃ ) ₂ but preferably denotes -CH3, and x and y mutually independently denote values between 1 and 32, with nonionic surfactants with R ³ = -CH3 and values of x from 15 to 32 and y of 0.5 and 1 .5 being very particularly preferred.

Further usable nonionic surfactants are the end group-terminated poly(oxyalkylated) nonionic surfactants of the formula R ¹ 0[CH ₂ CH(R ³ )0]x[CH2]kCH(OH)[CH ₂ ]jOR ² , in which R ¹ and R ² denote linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon residues with 1 to 30 carbon atoms, R ³ denotes H or a methyl, ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl or 2-methyl-2-butyl residue, x denotes values between 1 and 30, k and j denote values between 1 and 12, preferably between 1 and 5. If the value of x is≥ 2, each R ³ in the above formula

R ¹ 0[CH ₂ CH(R ³ )0]x[CH ₂ ] _k CH(OH)[CH ₂ ]jOR ² may be different. R ¹ and R ² are preferably linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon residues with 6 to 22 carbon atoms, residues with 8 to 18 C atoms being particularly preferred. H, -CH3 or -CH ₂ CH3 are particularly preferred for the residue R ³ . Particularly preferred values for x are in the range from 1 to 20, in particular from 6 to 15.

As described above, each R ³ in the above formula may be different if x≥ 2. In this manner, it is possible to vary the alkylene oxide unit in the square brackets. For example, if x denotes 3, the residue R ³ may be selected in order to form ethylene oxide (R ³ = H) or propylene oxide (R ³ = CH3) units, which may be attached to one another in any sequence, for example (EO)(PO)(EO), (EO)(EO)(PO), (EO)(EO)(EO),

(PO)(EO)(PO), (PO)(PO)(EO) and (PO)(PO)(PO). The value 3 for x has been selected here by way of example and may perfectly well be larger, the range of variation increasing as the value of x rises and for example comprising a large number of (EO) groups combined with a small number of (PO) groups or vice versa. Particularly preferred end group-terminated poly(oxyalkylated) alcohols of the above- stated formula have values of k=1 and j=1 , such that the above formula simplifies to R ¹ 0[CH2CH(R ³ )0]xCH ₂ CH(OH)CH ₂ OR ² . In the latter-stated formula, R ¹ , R ² and R ³ are defined as above and x denotes numbers from 1 to 30, preferably from 1 to 20 and in particular from 6 to 18. Particularly preferred surfactants are those in which the residues R ¹ and R ² comprise 9 to 14 C atoms, R ³ denotes H and x assumes values from 6 to 15.

The stated C chain lengths and degrees of ethoxylation or degrees of alkoxylation of the above-stated nonionic surfactants are statistical averages which, for a specific product, may be an integer or a fractional number. Due to production methods, commercial products of the stated formulae do not in the main consist of an individual representative, but instead of mixtures, whereby not only the C-chain lengths but also the degrees of ethoxylation or degrees of alkoxylation may be averages and consequently fractional numbers.

The most preferred nonionic surfactants are according to the formula:

wherein n is from 0 to 5 and m from 10 to 50, more preferably wherein n is from 0 to 3 and m is from 15 to 40, and even more preferably wherein n is 0 and m is from 18 to 25. Surfactants according to this formula were found to further reduce spotting of dishware treated in a machine dish washer. Preferably at least 50 wt. % of the nonionic surfactant comprised by the composition according to the invention is nonionic surfactant according to this formula. Such nonionic surfactants are commercially available, e.g. under the tradename Dehypon WET (Supplier: BASF) and Genapol EC50 (Supplier Clariant).

The above-stated nonionic surfactants may, of course, be used not only as individual substances, but also as surfactant mixtures of two, three, four or more surfactants.

Preferred is a detergent composition according to the invention wherein the nonionic surfactant comprises nonionic surfactant according to the formula:

wherein n is from 0 to 5 and m from 10 to 50, more preferably wherein n is from 0 to 3 and m is from 15 to 40, and even more preferably wherein n is 0 and m is from 18 to 25;

and wherein the composition further comprises from 3 to 35 wt. % of citric acid, citrate or a mixture thereof, wherein the weight of the citrate is based on the acid equivalent.

Particularly good results were achieved with further preferred detergent compositions according to the invention wherein the non-ionic surfactant comprises nonionic surfactant(s) according to the formula:

wherein n is from 0 to 5 and m from 10 to 50, more preferably wherein n is from 0 to 3 and m is from 15 to 40, and even more preferably wherein n is 0 and m is from 18 to 25; and

• wherein the amount of mixture of a) and b) is from 0.6 to 8.0 wt. %, and wherein a) comprises HEDP in an amount of from 0.5 to 6.0 wt. %; and wherein b) comprises alkali tripolyphosphate in an amount of 0.05 to 5.0 wt. %, and wherein the weight ratio between a) and b) is from 0.5:1 to 8:1

· and wherein the composition further comprises from 3 to 35 wt.% of citric acid, citrate or a mixture thereof, wherein the weight of the citrate is based on the acid equivalent.

Composition

Preferably the machine dish wash composition according to the invention comprises further detergent active components, more preferably detergent active components selected from the group consisting of enzymes, enzyme stabilizers, bleaching agents, bleach activator, bleach catalyst, bleach scavengers, drying aids, silicates, metal care agents, colorants, scents/perfumes, lime soap dispersants, anti-foam, anti-tarnish and anti-corrosion agents.

It is preferred that the detergent composition according to the invention comprises at least 5 wt. %, more preferably at least 8 wt. % and even more preferably at least 10 wt. % of bleaching agent by total weight of the composition. The bleaching agent of the present composition preferably comprise a chlorine-, or bromine-releasing agent or a peroxygen compound. Preferably, the bleaching agent is selected from peroxides (including peroxide salts such as sodium percarbonate), organic peracids, salts of organic peracids and combinations thereof. More preferably, the bleaching agent is a peroxide. Most preferably, the bleaching agent is a percarbonate. Examples of peroxides are acids and corresponding salts of monopersulphate, perborate monohydrate, perborate tetrahydrate, and percarbonate. Organic peracids useful herein include alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (e.g. peroxy-alpha-naphthoic acid), aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid), and phthaloyl amido peroxy caproic acid (PAP). Typical diperoxy acids useful herein include alkyl diperoxy acids and aryldiperoxy acids, such as 1 ,12-di-peroxy- dodecanedioic acid (DPDA), 1 ,9-diperoxyazelaic acid, diperoxybrassylic acid, diperoxysebacic acid and diperoxy-isophthalic acid, and 2-decyldiperoxybutane-1 ,4- dioic acid. Preferably the bleaching agent is present as dispersed particles. It is particularly preferred that the present composition comprises coated bleach particles, and it is further preferred that the coated bleach particles comprise a water-soluble coating. The water-soluble coating advantageously comprises a coating agent selected from alkali sulphate, alkali carbonate or alkali chloride and combinations thereof.

Preferably the coating contains sulphate. The coating of the bleaching agent can be done by, for example, crystallisation or by spray granulation. Suitable coated bleaching agents are described in, for example EP-A 0 136 580 and EP-A 0 863 842. The use of spray granulated coated percarbonate is most preferred.

The detergent composition may contain one or more bleach activators such as peroxyacid bleach precursors. Peroxyacid bleach precursors are well known in the art. As non-limiting examples can be named Ν,Ν,Ν',Ν'-tetraacetyl ethylene diamine (TAED), sodium nonanoyloxybenzene sulphonate (SNOBS), sodium

benzoyloxybenzene sulphonate (SBOBS) and the cationic peroxyacid precursor (SPCC) as described in US-A-4,751 ,015. Preferably the composition according to the invention comprises a bleach catalyst. It is particularly preferred that that the composition comprises a bleach catalyst which is a manganese complex, such as Mn-Me TACN, as described in EP-A-0458397, and/or the sulphonimines of US-A- 5,041 ,232 and US-A-5,047,163. It is advantageous that the bleach catalyst is present in the composition in the form of an encapsulate, notably an encapsulate that is separate from the bleach particles (to avoid premature bleach activation). Cobalt or iron catalysts can also be used. Preferably the composition according to the invention further comprises protease, amylase or a combination thereof and more preferably comprises a combination of protease and amylase.

Silicates are known ingredients in the field of machine dish wash detergent

compositions. Silicates are included to provide dish wash care benefits, and reduce corrosion of dishware and especially of glass and aluminium surfaces. Silicates may also have some builder activity, but in this specification silicates are not considered as builder. Silicates are preferably used in the detergent composition according to the invention. Particularly preferred silicates are sodium disilicate, sodium metasilicate and crystalline phyllosilicates or mixtures thereof. If present the total amount of silicates preferably is from 1 to 15 wt. %, more preferably form 2 to 10 wt. % and even more preferably from 2.5 to 5.0 wt. % by weight of the composition.

The detergent composition according to the invention may be in any suitable form such as for example a liquid, a (encapsulated) powder, grains, pastilles, a paste, a slurry, or a tablet.

The composition is preferably provided as a water-soluble or water-dispersible unit dose, in particular in the form of pouches (i.e. comprising non-shape stable ingredients, such as liquid and/or powders) or tablets. Preferably the unit dose is sized and shaped as to fit in the detergent cup of a conventional house-hold machine dishwasher, as is known in the art.

If the composition is in the form of a tablet, for the purpose of improving hygiene and consumer safety, it is highly preferred that the tablet is wrapped. The wrapper can be water-soluble or water-insoluble. Water-soluble wrappers, such as based on polyvinylalcohol (PVA) are preferred. This prevents direct contact of the detergent composition with the skin of the consumer when placing the unit dose in the detergent cup of a machine dishwasher. A further benefit of course is that the consumer also does not need to remove a water-soluble wrapping before placement in the detergent cup. Unit dose pouches can have one or multiple compartments. In case of multi- compartmented unit dose pouches, it is preferred that at least one compartment holds a powder or a liquid, such as a liquid surfactant.

Preferred unit dose tablets are those which have more than one visually distinct tablet region. Such regions can be formed by e.g. two distinct (colored) layers or a tablet having a main body and a distinct insert, such as forming a nested-egg. However oriented, one benefit of such multi-compartmental pouches/ multi-region tablets is that it can be used to reduce/prevent undesired chemical reactions between two or more ingredients during storage by (partial) physical segregation. More preferably the detergent composition according to the invention is in the form of a tablet with particular preference for multi-layered tablet. As multi-layered tablet, at least part of the bleach catalyst is advantageously in a separate layer from any oxidizing agent, such as percarbonate. The detergent composition according to the invention preferably comprises from 2.0 to 16 wt. % of binder, wherein preferably the binder comprises at least 50 wt. %, based on the total amount of binder, of polyethyleneglycol (PEG). The preferred PEG has an average molecular weight of from 2000 to 8000 g/mol, such as PEG4000.The addition of binder enhances structural integrity of the tablet, which can be observed by less broken tablets and/or less powder residue upon exposure of the tablets to mechanical stress, such as experienced during transport.

The detergent compositions according to the invention can be made using known methods and equipment in the field of machine dishwashing detergent composition manufacturing. The detergent composition according to the invention can be made by combining all the ingredients in the amounts as specified in composition according the invention followed by mixing. The invention further relates to the use of a mixture of a) phosphonates, phosphonic acids or a combination thereof, and b) phosphates, phosphoric acids or a combination thereof; in a detergent composition to reduce spotting on dishware and preferably on glass and/or metal surfaces treated in a machine dishwasher. Preferred aspects in the context of the detergent composition according to the invention are also applicable as preferred aspects in the context of the use according to the invention mutatis mutandis.

The invention is now illustrated by the following non-limiting examples. Examples

Spotting evaluation

Spotting was evaluated in a viewing cabinet, which was painted black on the inside. To assess the spotting, an article is placed in the cabinet and illuminated with some light source (Philips master TL-D 36 W / 865 2M, 120 cm long) from beneath in case of glass articles, or from above, in case of non-glass articles. The spotting score of an article is based on counting the number of spots. A spotting score of 9 indicates no spots, a spotting score of 1 indicates the article is full of spots.

Formulations according to Example 1 and Comparative A to C

Detergent compositions were prepared with a formulation as set out in Table 1. In each case, the respective ingredients were incorporated in powdered or granular form and dry-mixed before being compacted to form tablets. Table 1. Formulation according to Example 1 and Comparative A, B and C. Amounts represent wt. % of ingredients.

Machine Dish Wash Test

20 grams of detergent composition according to Example 1 or Comparative A, B or C were applied as detergent in a Miele GSL dishwasher. The following machine dish wash conditions were used:

· program: 50 degrees Celsius

• method of dosing detergent composition: via dispenser (detergent cup)

• water supply: water tank with water at 15 degrees Celsius

• ballast soil: 1 cup de-frozen Tensio soil

• Program repeats: 1

· Washes 6 A variety of dishware articles were placed in the machine dishwasher and subjected to the cleaning program using the conditions as described above. Subsequently the dishware articles were evaluated for spotting, the results thereof are given in Table 2. Table 2. Spotting results (higher number indicates less spotting).

The results from Comparative A represent the situation wherein no HEDP or STTP has been added to the detergent composition. As can be observed from the results, the presence of HEDP (Comparative B) or STTP (Comparative C) in the detergent composition improves spotting on Earthenware articles, but actually worsens spotting on glass and plastic articles. As such it is quite unexpected that by combining both HEDP and STTP (Example 1 ) in the detergent composition it improves spotting on glass and metal articles. In fact, the improvement in spotting of Example 1 shows that the combination of HEDP and STTP acts synergistically to improve spotting: it is more than what could be expected by the sum of the effects as observed from Comparative B (HEDP) and Comparative C (STTP) in view of Comparative A (no HEDP, no STTP).