The present disclosure relates to automatic dishwashing compositions, and the method of manufacture and the use of the same.

Household detergents are used widely in many applications including laundry care and for hard-surface cleaning such as in an automatic dishwasher. It is recognised that a common household detergent is usually made up of a number of different components, with one key component being a builder.

A builder is typically a small molecule, such as an aminocarboxylate, hydroxycarboxylate or a phosphate chelating ligand, and is used as a chelating agent to aid the removal/capture of metal ions in solution. The use of builders reduces the deposits of metal ion-based sediments (such as limescale) within automatic washing machines and the cleaning process is enhanced as certain stains incorporate a metal ion component, such as tea stains that comprise calcium/tannin complexes.

Indeed, small molecule builders provide a wide variety of functions during a wash cycle, in particular they impact both the alkalinity and pH buffering of the wash liquor, the ionic strength of the solution, the removal of both alkaline earth metal ions (affecting water hardness) and transition metal ions from washing solutions, the extraction of scale and metal ions from soils, they support re-dissolution and prevent soil redeposition. Builders also improve surfactant performance (as Ca ²⁺ and Mg ²⁺ ions may reduce the efficiency of surfactants) and can extract calcium ions from the cell walls of microorganisms weakening their outer surface and rendering them more vulnerable towards biocidals and preservatives.

Thus, the removal of small molecule builders from automatic dishwashing detergents is therefore both almost unheard of in the technical field and extremely challenging. Furthermore, certain ingredients (e.g. bleaching species, polymers or enzymes) are optimized for distinct operating conditions (such as pH, salt concentration/ionic strength, water hardness, etc.), meaning that the removal of builders from a composition impacts the remaining components in the formulations. Nonetheless, despite these obvious challenges, there is a need for a cost-effective, efficacious, benign system that does not use one or more small molecule builders. This is because efficacious small molecule builders are corrosive in material care tests (e.g. resulting in glass and decor corrosion) due to their high affinity for metal ions (high log K values). Such strong chelating ligands are also suspected of reducing the in-wash stability and activity of other metal-containing formula ingredients. For example, methyl glycine diacetic acid is capable of extracting the central metal ions from manganese bleach catalysts as well as from metalloenzymes in detergent formulations.

The set technical problem was therefore to develop a cost-effective formulation free from conventional small molecule builders and yet that has comparable performance to conventional detergent compositions. The present invention addresses the above technical problems and so in a first aspect of the present invention there is provided am automatic dishwashing (ADW) composition that contains less than 5% by weight of one or more small molecule builders; wherein the composition comprises one or more polymers. In contrast to conventional formulations, it was found that an automatic dishwashing composition free from standard, small-molecule carboxylates as builder components surprisingly displayed a comparable or even superior performance in applicative cleaning and shine tests compared to standard MGDA- or citrate-based ADW formulations, as well as minimal spotting and filming on the washed wares.

Preferably the one or more small molecule builders is/are selected from hydroxycarboxylates (such as citrate), aminocarboxylates (such as methyl glycine diacetic acid (MGDA), or N,N- dicarboxymethyl glutamic acid (GLDA)), dicarboxylic acid amines (such as iminodisuccinic acid (IDS) and/or phosphates (such as tri polyphosphate), or the salts thereof. The composition comprises one or more polymers, preferably polycarboxylates. By the term 'polycarboxylate' we mean any polymeric species comprising a carboxylic acid or carboxylate groups available for chelation. There is an inherent technical challenge in removing small molecules as the complex formation constant for polycarboxylates is significantly lower than, for example, log K _MGDA (Ca ²⁺ ), thus indicating a less favourable interaction of calcium ions with polycarboxylates, resulting in a higher concentration of Ca ²⁺ ions remaining in the wash liquor and consequently the associated detrimental effects on the wash performance as stronger chelating agents are beneficial to the soil removal process. Furthermore, while the small builder molecules form well-defined and understood coordination complexes with Ca ²⁺ and Mg ²⁺ ions, polyacrylates instead form ML2 complexes (L representing one carboxy unit) and their polymeric nature prevents the assignment of a definite structural assignment. The sequestration properties of polycarboxylates are dependent not only on the formation constants of their metal complexes, but also on the protonation equilibria of the polycarboxylates, on the reaction medium, the presence of potential co-monomers, the ionic strength of the wash liquor and the molecular weight of the polymer. The present invention must therefore balance these competing variables. Preferably the one or more polymer, such as the polycarboxylates, are present in an amount of from 3 to 25% by weight, such as from 5 to 20%, from 6 to 18%, from 7 to 16%, from 8 to 15%, or even from 9 to 13% by weight.

Advantageously the at least one polycarboxylate polymer comprises an acrylic acid monomer. The at least one polycarboxylate polymer may be a homopolymer and/or a copolymer and/or a terpolymer.

Where at least one polycarboxylate polymer is an acrylic acid homopolymer, the homopolymer preferably has a molecular weight of from 2,000 to 10,000, such from 3,000 to 9,000, or even from 4,000 to 8,000. Such a polymer is preferably present in an amount of from 0.1 to 5% by weight, such as from 0.2 to 4.5%, from 0.3 to 4%, from 0.3 to 3.5%, from 0.4 to 3%, from 0.5 to 2.5%, from 0.6 to 2%, or even from 0.7 to 1.5% by weight. Preferably the at least one polycarboxylate comprises a sulphonic acid monomer. Where the polycarboxylate comprises a sulphonic acid monomer it is preferably present in an amount of from 4 to 14% by weight, such as from 5 to 13%, from 6 to 12% or even from 7 to 11% by weight.

Preferred monomers containing sulphonic acid groups are those of the formula: R ¹ (R ² )C=C(R ³ )-X-S0 ₃ H in which R ¹ to R ³ mutually independently denote -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 -NH2 , -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 -(CH2)n- with n=0 to 4, - COO-(CH ₂ ) - with k=l to 6, -C(0)-NH-C(CH ₃ ) ₂ - and CH(CH ₂ CH ₃ )-.

Preferred among these monomers are those of the formulae:

H C=CH-X-S0 ₃ H H C=C(CH ₃ )-X-S0 ₃ H H0 ₃ S-X-(R ⁵ )C=C(R ⁶ )-X-S0 ₃ H in which R ⁵ and R ⁶ are mutually independently selected from -H, -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2 and X denotes an optionally present spacer group which is selected from-(CH2) _n - with n= 0 to 4, -COO-(CH )k with k=l to 6, -C(0)-NH-C(CH ₃ ) ₂ - and -C(0)-NH-CH(CH CH ₃ )-. Preferred monomers containing sulphonic acid groups are here 1-acrylamido-l- propanesulphonic acid, 2-acrylamido-2-propanesulphonic acid, 2-acrylamido-2-methyl-l- propanesulphonic acid, 2-methacrylamido-2-methyl-l-propanesulphonic acid, 3- methacrylamido-2-hydroxypropane-sulphonic acid, allylsulphonic acid, methallylsulphonic acid, allyloxybenzenesulphonic acid, methallyloxybenzenesulphonic acid, 2-hydroxy-3-(2- propenyloxy)propanesulphonic acid, 2-methyl-2-propene-l-sulphonic acid, styrenesulphonic acid, vinylsulphonic acid, 3-sulphopropyl acrylate, 3-sulfopropyl methacrylate, sulphomethacrylamide, sulphomethylmethacrylamide and mixtures of the stated acids orthe water-soluble salts thereof. Particularly preferred is 2-acrylamido-2-methyl-l- propanesulphonic acid.

The sulphonic acid groups may be present in the polymers entirely or in part in neutralized form, i.e. the acidic hydrogen atom of the sulphonic acid group may be replaced in some or all of the sulphonic 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 sulphonic acid groups.

The molar mass of the sulphonic acid polymers preferably used according to the invention may be varied in order to tailor the properties of the polymers to the desired intended application. Preferred machine dishwashing detergents are characterized in that the copolymers have molar masses of 2000 to 200,000 g mol ¹ , preferably of 4000 to 25,000 g mol ¹ and in particular of 5000 to 15,000 g mol ¹ . The polymer preferably has a pH of from 3 to 5, such as from 3.5 to 4.5.

The polycarboxylate may be a copolymer comprising a sulphonic acid monomer and an acrylic acid monomer.

Advantageously the at least one polycarboxylate comprises a maleic acid monomer. Such a polymer is preferably present in an amount of from 0.1 to 5% by weight, such as from 0.2 to 4.5%, from 0.3 to 4%, from 0.3 to 3.5%, from 0.4 to 3%, from 0.5 to 2.5%, from 0.6 to 2%, or even from 0.7 to 1.5% by weight.

The polymer may have a viscosity of from 500 to 3000 mPa.s, such as from 750 to 2500 mPa.s, preferably from 1000 mPa.s to 2000 mPa.s. Such a copolymer may have a molecular weight (Mw) of from 10,000 to 100,000 g mol-1, such as from 20,000 to 80,000 g mol-1, from 30,000 to 70,000 g mol-1, and preferably from 45,000 to 55,000 g mol-1.

The polycarboxylate may be a copolymer comprising a maleic acid monomer and an acrylic acid monomer. The acrylic acid-maleic acid copolymer may be formed from 2-propenoic acid and 2,5- furandione, and preferably has a pH or from 7 to 9, such as from 7.5 to 8.5, assessed by DIN19268. Most preferably, the composition comprises an acrylic acid homopolymer, an acrylic acid- sulphonic acid, and/or an acrylic acid-maleic acid copolymer.

Preferably the composition comprises one or more polycarboxylate homopolymers and one or more polycarboxylate copolymers. Advantageously the homopolymer(s) and copolymer(s) are present in a ratio of from 1:20 to 1:2, preferably from 1:15 to 1:5, respectively.

Preferably, the composition comprises polyepoxysuccinic acid (PESA) or derivatives thereof.

Polyepoxysuccinic acid is also known as epoxysuccinic acid homopolymer, polyoxirane-2,3- dicarboxylic acid, 2,3-oxiranedicarboxylic acid homopolymer, or poly(l-oxacyclopropane-2,3- dicarboxylic acid); and has the general structure: and where the derivatives thereof have the general structure: where R may be hydrogen or any organic chain (but preferably an ester such as C1-4 alkyl) and where M may be any cation (preferably such as Na ⁺ , H ⁺ , K ⁺ , and/or NH4 ⁺ ) All references to PESA hereafter are to be taken to refer to polyepoxysuccinic acid or derivatives thereof, unless otherwise stated.

Advantageously, the PESA has a molecular weight (M _w ) of from 100 to 10,000 g mol ¹ , preferably from 400 to 2000 g mol ¹ , such as from 1000 to 1800 g mol ¹ . The PESA may have from 2 to 100 repeating monomer units, such as from 2 to 50, 2 to 45, 2 to 20 or even 2 to 10.

Advantageously, the composition comprises PESA in an amount of from 0.1 to 5% by weight, such as from 0.1 to 4%, from 0.15 to 3%, from 0.2 to 1.9%, from 0.25 to 1.5%, or even 0.6 to 1.1%. PESA is preferably present in an amount of from 5 to 20% by weight, such as from 8 to 19%, or from 9 to 15%, relative to the total quantity of polymers present.

The composition preferably comprises sodium carbonate, advantageously in a quantity from 11 to 45% by weight, such in a quantity from 12 to 40% by weight, from 18 to 39% by weight, from 21 to 35% by weight.

The composition may also comprise sodium bicarbonate. If so, it is preferably present in an amount of from 0.5 to 5% by weight, such as from 0.9 to 4.5%, from 1 to 4%, from 1.3 to 3.5%, or even from 1.7 to 3% by weight.

The composition advantageously comprises phosphonate, such as l-hydroxyethylidene-1,1- diphosphonic acid (HEDP), preferably in a quantity of from 4 to 8% by weight, such as from 5 to 7% by weight. Although having the potential to act as a chelating agent, addition of a phosphonate primarily serves the function of crystal growth inhibitor and as such does not fall within the scope of a 'small molecule builder' as defined herein.

The composition may include one or more surfactants. Any of non-ionic, anionic, cationic, amphoteric or zwitterionic surface active agents or suitable mixtures thereof may plausibly be used. Many such suitable surfactants are described in Kirk Othmer's Encyclopedia of Chemical Technology, 3rd Ed., Vol. 22, pp. 360-379, "Surfactants and Detersive Systems", incorporated by reference herein. In general, bleach-stable surfactants are preferred according to the present invention. In the case of automatic dishwashing compositions, it is preferred to minimise the amount of anionic surfactant. Accordingly, preferably the composition comprises no more than 2 wt%, no more than 1 wt%, or no, anionic surfactant. Preferably the composition comprises no more than 5 wt%, no more than 1 wt %, or no, ionic surfactant of any type.

Non-ionic surfactants are especially preferred instead for automatic dishwashing products, preferably comprising from 5 to 25% by weight, such as from 10 to 20%, from 11 to 19%, from 12 to 18%, or from 13 to 17%, of one or more nonionic surfactants.

Preferably, the non-ionic surfactant is an optionally end capped alkyl alkoxylate. A preferred class of nonionic surfactants are ethoxylated non-ionic surfactants prepared by the reaction of a monohydroxy alkanol or alkyl phenol with 6 to 20 carbon atoms. Preferably the surfactants have at least 12 moles per mole of alcohol or alkyl phenol. Particularly preferred non-ionic surfactants are the non-ionics from a linear chain fatty alcohol with 10-20 carbon atoms and at least 5 moles, of ethylene oxide per mole of alcohol. According to one embodiment of the invention, the non-ionic surfactants additionally may comprise propylene oxide units in the molecule. Preferably these PO units constitute up to 25 % by weight, preferably up to 20 % by weight and still more preferably up to 15 % by weight of the overall molecular weight of the non-ionic surfactant.

Preferably, the one or more nonionic surfactants comprises a mixed alkoxylate fatty alcohol non-ionic surfactant, preferably comprising a greater number of moles of the lower alkoxylate group than of the higher alkoxylate group in the molecule. Preferably the mixed alkoxylate fatty alcohol non-ionic surfactant comprises at least two of EO, PO or BO groups and most preferably only EO and PO groups.

By the term 'higher alkoxylate' it is meant the alkoxylate group having the greatest number of carbon atoms in that alkoxylate group. By the term 'lower alkoxylate' it is meant the alkoxylate group having the lowest number of carbon atoms in that alkoxylate group. Thus, for a mixed alkoxylate fatty alcohol corn-prising ethoxylate (EO) and propoxylate (PO) groups the EO is the lower alkoxylate and the PO is the higher alkoxylate. Thus, the detergent compositions of the invention comprise mixed alkoxylate fatty alcohols comprising a greater number of EO groups than PO groups. The same applies to other mixed alkoxylates such as those containing EO and butoxylate (BO) or even PO and BO groups. The mixed alkoxylate fatty alcohol non-ionic surfactant preferably has a mole ratio of the lower alkoxylate group to the higher alkoxylate group is at least 1.1:1, most preferably of at least 1.8:1, especially at least 2:1. It is also preferred that the mixed alkoxylate fatty alcohol non-ionic surfactant comprises between 3 to 5 moles of the higher alkoxylate group and between 6 to 10 moles of the higher lower group, preferably 4 or 5 moles of PO and 7 or 8 moles of EO and most preferably 4 moles of PO and 8 moles of EO.

Preferably the mixed alkoxylate fatty alcohol non-ionic surfactant has 12-18 carbon atoms in the alkyl chain. It is especially preferred that the mixed alkoxylate fatty alcohol nonionic surfactant comprises at least two of EO, PO or BO groups and especially a mixture of EO and PO groups, preferably EO and PO groups only.

It is most preferred that the mole ratio of the lower alkoxylate group to the higher alkoxylate group is at least 1.1:1, more preferably at least 1.5:1, and most preferably at least 1.8:1, such as at least 2:1 or even at least 3:1.

An especially preferred mixed alkoxylate fatty alcohol nonionic surfactant according to the present invention comprises between 3 to 5 moles of the higher alkoxylate group and between 6 to 10 moles of the lower group. Especially preferred are mixed alkoxylate fatty alcohol nonionic surfactants having 4 or 5 moles of the higher alkoxylate group and 7 or 8 moles of the lower alkoxylate group. According to one aspect of the invention a mixed alkoxylate fatty alcohol nonionic surfactant having 4 or 5 PO moles and 7 or 8 EO moles is especially preferred and good results have been obtained with for surfactants with 4 PO moles and 8 EO moles. In an especially preferred embodiment, the mixed alkoxylate fatty alcohol nonionic surfactant is C12-15 8EO/4PO.

Surfactants of the above type which are ethoxylated mono-hydroxy alkanols or alkylphenols which additionally comprise poly-oxyethylene-polyoxypropylene block copolymer units may be used. The alcohol or alkylphenol portion of such surfactants constitutes more than 30%, preferably more than 50%, more preferably more than 70% by weight of the overall molecular weight of the non-ionic surfactant. The mixed alkoxylate fatty alcohol non-ionic surfactants used in the compositions of the invention may be prepared by the reaction of suitable monohydroxy alkanols or alkylphenols with 6 to 20 carbon atoms. Preferably the surfactants have at least 8 moles, particularly preferred at least 10 moles of alkylene oxide per mole of alcohol or alkylphenol. Particularly preferred liquid mixed alkoxylate fatty alcohol non-ionic surfactants are those from a linear chain fatty alcohol with 12-18 carbon atoms, preferably 12 to 15 carbon atoms and at least 10 moles, particularly preferred at least 12 moles of alkylene oxide per mole of alcohol. When PO units are used, they preferably constitute up to 25% by weight, preferably up to 20% by weight and still more preferably up to 15% by weight of the over-all molecular weight of the non-ionic surfactant.

The claimed mixed alkoxylate fatty alcohol non-ionic surfactants, and especially the C12-15 fatty alcohol 8EO,4PO surfactant exhibit: excellent wetting of plastic, glass, ceramic and stainless steel; excellent temperature stability up to 90 °C for processing; good compatibility with thickeners typically used in the detergent compositions (e.g. PEG); and stability in alkaline conditions. Alternatively, glucamide surfactants prepared from sugars and natural oils, may be used. A preferred example is oleyl glucamide. Also suitable are alkyl polyglycosides (APGs), which are plant-derived from sugars, these surfactants are usually glucose and fatty alcohol derivatives. The use of a mixture of any of the aforementioned nonionic surfactants is suitable in compositions of the present invention.

The composition may include one or more enzymes. It is preferred that the one or more enzymes are selected from proteases, lipases, amylases, cellulases and peroxidases, with proteases and amylases being most preferred. It is most preferred that protease and/or amylase enzymes are included in the compositions according to the invention as such enzymes are especially effective in dishwashing detergent compositions. More than one species may be used. The total quantity of enzymes is preferably from 1 to 5% by weight, such as from 2 to 4%.

The composition may include one or more bleaching agents, preferably in combination with one or more bleach activators and/or one or more bleach catalysts. The bleaching agent is preferably selected from the group consisting of an oxygen-releasing bleaching agent, a chlorine-releasing bleaching agent and mixtures of two or more thereof. More preferably, the bleaching agent is or comprises an oxygen-releasing bleaching agent.

The bleaching agent may comprise the active bleach species itself or a precursor to that species. Preferably, the bleaching agent is selected from the group consisting of an inorganic peroxide, an organic peracid and mixtures of two or more thereof. The terms "inorganic peroxide" and "organic peracid" encompass salts and derivatives thereof. Inorganic peroxides include percarbonates, perborates, persulphates, hydrogen peroxide and derivatives and salts thereof. The sodium and potassium salts of these inorganic peroxides are suitable, especially the sodium salts. Sodium percarbonate is particularly preferred.

The active bleaching agent is preferably present in an amount of from 5 to 25% by weight, such as from 7 to 23%, from 9 to 19%, or from 11 to 17%.

The composition may further comprise one or more bleach activators and/or bleach catalysts. Any suitable bleach activator may be included, for example TAED, if this is desired for the activation of the bleaching agent. Any suitable bleach catalyst may be used, for example manganese acetate or dinuclear manganese complexes such as those described in EP 1741774 Al, the contents of which are incorporated herein by reference. The organic peracids such as perbenzoic acid and peroxycarboxylic acids e.g. phthalimidoperoxyhexanoic acid (PAP) do not require the use of a bleach activator or catalyst as these bleaches are active at relatively low temperatures such as about 30°C.

Silver/copper corrosion inhibitors may be present. Preferred silver/copper corrosion inhibitors are benzotriazole (BTA) or bis-benzotriazole and substituted derivatives thereof Other suitable inhibitors are organic and/or inorganic redox-active substances and paraffin oil. Benzotriazole derivatives are those compounds in which the available substitution sites on the aromatic ring are partially or completely substituted. Suitable substituents are linear or branch-chain Cl-20 alkyl groups and hydroxyl, thio, phenyl or halogen such as fluorine, chlorine, bromine and iodine. A preferred substituted benzotriazole is tolyltriazole.

The detergent composition may be in any form, such as powder, tablet, gel or contained in a soluble container and composition may be comprises of a plurality of compositions. For example, the composition may be contained in a water-soluble container, preferably a multi compartment container. The multi-compartment container may comprise a composition in the form of a solid, liquid, gel or paste and at least one further composition in the form of a solid, liquid, gel or paste.

By the term 'water-soluble' or 'water-dispersible' container as used herein, it is meant a package which at least partially dissolves in water or disperses in water at 20 °C within 10 minutes to allow for egress of the contents of the package into the surrounding water. Preferably, the product is in a unit dose or monodose form. In other words, the product comprises one or more compositions in the quantity required for a single wash cycle of a machine dishwasher. The terms monodose and unit dose may be used interchangeably throughout this disclosure.

In a second aspect of the invention there is provided a method of making a composition according to the present invention. In a third aspect there is provided the use of a composition as defined in the present invention in an automatic dishwasher. It is intended that all described features can be combined with one or more other features in any combination. All percentages are by weight unless otherwise specified. All references to 'between' and percentages are intended to include the stated end points and so are equivalent to 'from' and 'to'. The invention is described in the following non-limiting Examples.

Examples

Two compositions according to the invention were prepared and compared to a detergent composition containing a standard small molecule builder. The details of the compositions are set out in Table 1.

Table 1 Shine Performance

A Shine Performance test was run using the inventive formulation versus the benchmark compositions.

Machine: Bosch Program: Eco Water Hardness:21"GH Results: Consumer impression: after 5 runs Evaluators: 2 trained judges

Scoring System:

5 - extremely strong Spotting/Filming 4 - very strong Spotting/Filming S - strong Spotting/Filming 2 - slight Spotting/Filming 1 - no Spotting/Filming Table 2

Cleaning Performance

Standard IKW cleaning performance trials were conducted using the inventive formulations and the benchmark composition. The results are provided in Table S. Table 3

Water Hardness:21"GH Miele G 1222 SC GSL Program: P3/8m

As can be seen from the collated performance results above, the inventive compositions have a cleaning performance profile comparable to the benchmark formulation. It can be concluded that compositions according to the present invention are capable of providing the performance of a standard detergent despite the absence of small molecule builders.

The invention is defined by the claims.