GB2307696A - Machine dishwashing compositions - Google Patents

Abstract

A detergent composition, with enhanced glass and china care, for use in a dishwashing method, contains a) a detergent component selected from the group consisting of a surfactant, a water-soluble builder compound and any mixtures thereof; and b) a base supported copolymer comprising a copolymer adsorbed and/or absorbed onto a base of solid water-soluble inorganic compound. The copolymer is obtainable by condensation polymerisation of a) an ammonium or alkali metal silicate; and b) an organic silicon compound, selected from the group consisting of (i) alkali metal siliconates (ii) alkoxysilanes; and any mixtures thereof wherein the ammonium or alkali metal silicate and organic silicon compound components of the copolymer are present such that the weight ratio of Si present as the organic silicon compound component to the total Si content of the copolymer is from 0.0002:1 to 0.05:1, and wherein the base supported copolymer has a water content of between 10 to 35% by weight.

Description

MACHINE DISHWASHING COMPOSITIONS Technical Field The present invention relates to detergent compositions, adapted for use in machine dishwashing, exhibiting enhanced glassware and chinaware protection.

Backeround to the Invention Compositions designed for use in automatic dishwasher machines are well known, and a consistent effort has been made by detergent manufacturers to improve the cleaning and/or rinsing efficiency of said compositions on chinaware, glassware and silverware, as reflected by numerous patent publications.

It is well understood, that in the field of machine dishwashing, detergent compositions typically contain an alkalinity system. Under certain circumstances, silicate-based alkalinity systems may lead to the deposition of silicate onto the surface of glassware and chinaware. The deposited silicate has a protective function. However, use of too high levels of silicate may result in the formation of an amorphous uneven silicate layer which has a different refractory index to bulk glass, resulting in iridescence, visually noticeable as a rainbow colouration. If layered deposition is allowed to continue the surface of the glass may become permanently clouded and opaque. The uneven nature of the silicate layer may also provide irregular protection of patterned glassware and chinaware, resulting in areas of pattern loss.

It has now been found that the inclusion of a basr -supported copolymer of an ammonium or alkali metal silicate with an organic silicon compound, in the detergent formulation, enables the formation of a uniform silicate layer.

The uniformity of the protective silicate layer results in reduced permanent clouding and enhanced glass and china pattern protection and thus a more pleasing visual appearance. The mechanism behind these benefits is believed to be the more uniform and equally distributed silicate layer providing a more uniform level of protection.

French patent application number 9415532 describes an unsupported copolymer of similar chemical composition. Use of the base support material, as a carrier, enhances the performance of the copolymer in the protection of glassware and chinaware.

The base supported copolymer improves protection of glassware and chinaware surfaces without adversely affecting the cleaning power of the detergent composition.

The present invention is thus concerned with a detergent composition, employed in a dish washing method, having enhanced glassware and chinaware protection properties, as well as good cleaning performance.

Summarv of the Invention There is provided a detergent composition, adapted for use in a dishwashing method, containing a) a detergent component selected from the group consisting of a surfactant, a water-soluble builder compound and any mixtures thereof; and b) a base supported copolymer comprising a copolymer adsorbed and/or absorbed onto a base of solid water-soluble inorganic compound, characterized in that said copolymer is obtainable by condensation polymerisation of a) an ammonium or alkali metal silicate of molar ratio Si20/M20 of from 0.5 to 4, where the symbol M represents an ammonium or an alkali metal cation; and b) an organic silicon compound, selected from the group consisting of (i) alkali metal siliconates of formula RnSi(O)p(OH)4-n-p (ii) alkoxysilanes of formula RnSi(OR')4 ; and any mixtures thereof where, R represents a hydrocarbon group, containing from 1 to 20 carbon atoms, which may optionally contain one or more nitrogen, oxygen or halogen atom; M represents an ammonium or alkali metal cation (n + p) is a number of less than or equal to 4, where n is between 1 and 3, and p is greater than or equal to 1 R' represents a linear or branched chain alkyl group containing between 1 and 6 carbon atoms; wherein the ammonium or alkali metal silicate and organic silicon compound components of the copolymer are present such that the weight ratio of Si present as the organic silicon compound component to the total Si content of the copolymer is from 0.0002:1 to 0.05:1, and wherein the base supported copolymer has a water content of between 10 to 35% by weight.

Detailed DesenD-don of the Invention The present detergent compositions contain a detergent component selected from the group consisting of a surfactant, a water-soluble builder compound, and any mixtures thereof, and a base supported copolymer.

Machine dishwashin compositions The compositions herein are adapted for use in a machine dishwashing method. Such compositions are formulated to enable the removal of, typically food based, soils and stains from soiled tableware under the conditions present in a machine dishwasher. Typically the compositions are low foaming, preferably containing only low levels of low-foaming surfactants.

Water-soluble builder compound The compositions of the present invention may contain a water-soluble builder compound, typically present at a level of from 0% to 80% by weight, preferably from 10% to 70% by weight, most preferably from 20% to 60% by weight of the composition.

Suitable water-soluble builder compounds include the water soluble monomeric polycarboxylates, or their acid forms, homo or copolymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxylic radicals separated from each other by not more that two carbon atoms, carbonates, bicarbonates, borates, phosphates, and mixtures thereof.

The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance.

Suitable carboxylates containing one carboxy group include the water soluble salts of lactic acid, glycolic acid and ether derivatives thereof.

Polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and furnaric acid, as well as the ether carboxylates and the sulfinyl carboxylates. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates described in British Patent No. 1,379,241, lactoxysuccinates described in British Patent No. 1,389,732, and aminosuccinates described in Netherlands Application 7205873, and the oxypolycarboxylate materials such as 2-oxa-1,1,3-propane tricarboxylates described in British Patent No. 1,387,447.

Polycarboxylates containing four carboxy groups include oxydisuccinates disclosed in British Patent No. 1,261,829, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane tetracarboxylates and 1,1,2,3-propane tetracarboxylates.

Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives disclosed in British Patent Nos. 1,398,421 and 1,398,422 and in U.S. Patent No. 3,936,448, and the sulfonated pyrolysed citrates described in British Patent No. 1,439,000.

Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis,cis,cistetracarboxylates, cyclopentadienide pentacarboxylates, 2,3,4,5tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran - cis dicarboxylates, 2,2,5,5-tetrahydrofuran tetracarboxylates, 1,2,3,4,5,6- hexane - hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1,425,343.

Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, more particularly citrates.

The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as useful builder components.

Borate builders, as well as builders containing borate-forming materials that can produce borate under detergent storage or wash conditions can also be used but are not preferred at wash conditions less that about 50"C, especially less than about 40"C.

Examples of carbonate builders are the alkaline earth and alkali metal carbonates, including sodium carbonate and sesqui-carbonate and mixtures thereof with ultra-fine calcium carbonate as disclosed in German Patent Application No. 2,321,001 published on November 15, 1973.

Specific examples of water-soluble phosphate builders are the alkali metal tripolyphosphates, sodium, potassium and ammonium pyrophosphate, sodium and potassium and ammonium pyrophosphate, sodium and potassium orthophosphate, sodium polymeta/phosphate in which the degree of polymerization ranges from about 6 to 21, and salts of phytic acid.

Surfactant Suitable surfactants are anionic, cationic, nonionic ampholytic and zwitterionic surfactants and mixtures thereof. Automatic dishwashing machine products should be low foaming in character and thus the foaming of the surfactant system must be suppressed or more preferably be low foaming, typically nonionic in character. The surfactant system is typically present at a level of from 0.2% to 30% by weight, more preferably from 0.5% to 10% by weight, most preferably from 1% to 5% by weight of the compositions.

A typical listing of anionic, nonionic, ampholytic and zwitterionic classes, and species of these surfactants, is given in U.S.P. 3,929,678 issued to Laughlin and Heuring on December, 30, 1975. A list of suitable cationic surfactants is given in U.S.P. 4,259,217 issued to Murphy on March 31,1981. A listing of surfactants typically included in automatic dishwashing detergent compositions is given for example, in EP-A-0414 549 and PCT Applications No.s WO 93/08876 (attorney's docket no. CM465M) and WO 93/08874 (attorney's docket no. CM595M)..

Nonionic surfactant Essentially any nonionic surfactants useful for detersive purposes can be included in the compositions. Preferred, non-limiting classes of useful nonionic surfactants are listed below.

Nonionic ethoxvlated alcohol surfactant The alkyl ethoxylate condensation products of aliphatic alcohols with from about 1 to about 25 moles of ethylene oxide are suitable for use herein. The alkyl chain of the aliphatic alcohol can either be straight or branched, primary or secondary, and generally contains from 6 to 22 carbon atoms.

Particularly preferred are the condensation products of alcohols having an alkyl group containing from 8 to 20 carbon atoms with from about 2 to about 10 moles of ethylene oxide per mole of alcohol.

Nonionic ethoxvlated/propoxylated fattv alcohol surfactant The ethoxylated C6-C18 fatty alcohols and C6-Clg mixed ethoxylated/propoxylated fatty alcohols are suitable surfactants for use herein, particularly where water soluble. Preferably the ethoxylated fatty alcohols are the C1 O-C18 ethoxylated fatty alcohols with a degree of ethoxylation of from 3 to 50, most preferably these are the C1 2-Cl8 ethoxylated fatty alcohols with a degree of ethoxylation from 3 to 40.

Preferably the mixed ethoxylated/propoxylated fatty alcohols have an alkyl chain length of from 10 to 18 carbon atoms, a degree of ethoxylation of from 3 to 30 and a degree of propoxylation of from 1 to 10.

Nonionic EO/PO condensates with propvlene dVCQI The condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol are suitable for use herein. The hydrophobic portion of these compounds preferably has a molecular weight of from about 1500 to about 1800 and exhibits water insolubility. Examples of compounds of this type include certain of the commercially-available PluronicTM surfactants, marketed by BASF.

Nonionic EO condensation products with propylene oxide/ethylene diamine adducts The condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenediamine are suitable for use herein. The hydrophobic moiety of these products consists of the reaction product of ethylenediamine and excess propylene oxide, and generally has a molecular weight of from about 2500 to about 3000. Examples of this type of nonionic surfactant include certain of the commercially available TetronicTM compounds, marketed by BASF Base supported copolymer The present composition contains a base supported copolymer comprising a copolymer absorbed and/or adsorbed onto a base of solid water-soluble inorganic compound.

The base support material is a carrier, delivering the copolymer to the wash solution, in the desired state to obtain maximum protection of glassware and chinaware. The base can be any water-soluble substantially inert, absorbent, solid inorganic salt preferably selected from the group consisting of alkali metal, alkaline earth metal and ammonium carbonate, bicarbonate, sulphate, borate, perborate, metasilicate, phosphates or polyphosphates, such as, sodium tripolyphosphate or any mixture thereof, and preferably in particulate form. The preferred base material is a sodium carbonate or bicarbonate. The base support material is present at 30 to 75% , preferably 40 to 75% by weight, of the hydrous base supported copolymer. The dry weight ratio of solid water-soluble inorganic support compound to silicate compound is preferably 60:40 to 70:30.

The copolymer is obtained by condensation polymerisation of an ammonium or alkali metal silicate of molar ratio Si20/M20 of from 0.5 to 4, preferably from 1.2 to 3.5, where M represents an ammonium or alkali metal cation, and an organic silicon compound.

The ammonium or alkali metal silicate and organic silicon components of the copolymer are present such that the weight ratio of Si present as the organic silicon compound component to the total Si content of the copolymer is from 0.0002:1 to 0.05:1, preferably 0.002:1 to 0.02:1, preferably 0.003:1 to 0.006:1.

The copolymer has a water content of between 10 to 35%, preferably 14 to 25% by weight particularly 16 to 20%.

The ammonium or alkali metal silicate is preferably any of ammonium, sodium, potassium, lithium silicate, preferably sodium silicate. The organic silicon compound is selected from the group consisting of (i) alkali metal siliconates of formula RnSi(O)p(OH)4-n-p (ii) alkoxysilanes of formula RnSi(OR')4-n where, R represents a hydrocarbon group, containing from 1 to 20 carbon atoms, which may optionally contain one or more nitrogen, oxygen or halogen atom; M represents an ammonium or alkali metal cation (n + p) is a number of less than or equal to 4, where n is between 1 and 3, and p is greater than or equal to 1 R' represents a linear or branched chain alkyl group containing between 1 and 6 carbon atoms;; The R hydrocarbon group can be any of the linear or branched alkyl groups, such as, methyl, ethyl, propyl, butyl, hexyl, octyl, dodecyl, octadecyl; the cycloalkyl groups, such as, cyclopentyl, cyclohexyl, cycloheptyl; the aryl groups, such as, phenyl, napthyl; the arylalkyl or alkylaryl groups, such as, tolyl, xylyl; the alkenyl groups, such as, vinyl, allyl: the alkyleneanune and polyalylenepolyamine groups, such as, diethylenediamine and the oxalkylene, polyoxyalkylene, oxyalkylenamine and the polyoxyalkyleneamine groups.

The R' symbol represents any hydrocarbon group, containing from 1 to 6 carbon atoms, preferably 1 to 2 carbon atoms.

The alkali metal siliconates are preferably selected from the group consisting of: sodium or potassium methylsiliconates of formula CH3 Si (ONa)3 or CH3 Si(OK)3 , sodium or potassium propylsiliconates of formula C3H7 Si(ONa)3 or C3H7 Si(OK)3 sodium or potassium butylsiliconates of formula C4H9 Si(ONa)3 or C4H9, Si(OK)3, sodium or potassium hexylsiliconates of formula C6H13 Si(ONa)3 or C6H13 Si(OK)3 sodium or potassium octylsiliconates of formula CgH17 Si(ONa)3 or C8H17 Si(OK)3, sodium or potassium dimethylsiliconates of formula (CH3)2 Si (ONa)2 or (CH3)2 Si (OK)2, sodium or potassium methylpropylsiliconates of formula (CH3)(C3H7)Si(ONa)2 or (CH3)(C3H7 Si(OK)2, sodium or potassium methylbutylsiliconates of formula methy exylsiliconates of formula (CH3)(C6H1 3)Si(ONa)2 or (CH3)(C6H1 3)Si(OK)2, sodium or potassium methyloctylsiliconates of formula (CH3 )(C8H17 )S i(ONa)2 or (CH3)(C8H1 7)Si(OK)2 and any mixtures thereof.

Commercial solutions of potassium methylsilicate containing 40 to 50% by weight of active material, are particularly suitable.

The alkoxysilanes are preferably selected from the group consisting of; methyltrimethoxysilane of formula CH3 Si (OMe)3, methyltriethoxysilane of formula CH3 Si (OEt)3, octyltrimethoxysilane of formula C8H17 Si (OMe)3, octyltriethoxysilane of formula C8H17 Si (OEt)3, diethylenediaminetriethoxysilane of formula H2N-(CH2)2 -NH-(CH2)2 Si(OEt)3 dimethyldimethoxysilane of formula (CH3)2 Si(OMe)2,trimethylmethoxysilane of formula (CH3)3 Si(OMe), dimethyldiethoxysilane of formula (CH3)2 Si(OEt)2, trimethylethoxysilane of formula (CH3)3 Si(OEt) and any mixtures thereof.

Process for making copolymer The base supported copolymer can be obtained by blending a solid watersoluble inorganic compound (base support material) with a mixture of a hydrous solution of an ammonium or alkali metal silicate, containing between 35 and 55% active material, preferably 35 to 50%, and a siliconate, preferably in a hydrous solution containing between 40 to 50 % active material. The components can be mixed in any form of mixing device, for example, a rapid mixer or atomizer, at a temperature of between 10 and 80 "C. Alternatively, the base support material may be blended with a mixture of a hydrous solution of ammonium or alkali metal silicate, containing between 35 and 55% active material, preferably 35 to 50% and an alkoxysilane.

The mixed components are dried at a temperature of 20 to 1 600C for a period of time determined such that the resulting mixture contains 10 to 35%, preferably 14 to 25% water content expressed by mass of dried base supported copolymer. Water content is determined by loss to heat at 9000C and acid titration. Drying can be carried out by any method, preferably by a rotary furnace, by atomization, in a rapid mixer, in a flash dryer or on a fluid bed, and less preferably, by spray-drying.

The solid matter obtained can then be reduced to a powder to obtain a size distribution suitable to the detergent formulation in which it will be incorporated. The particle size of the components of a granular composition, in accordance with the invention, should preferably be such that no more than 5% of particles are greater than 1.4mum in diameter and not more than 5% of particles are less than 0.15mum in diameter.

A variation on the above procedure, for obtaining supported copolymer, can be achieved by spraying a mixture of a hydrous solution of the ammonium or alkali silicate and the organic silicon compound, onto the base support material. The components are dried at a temperature of between 20 and 95 C, preferably 70 to 950C for a period of time such that the water content of the resulting mixture is between 10 and 35%, preferably 14 to 25%, by mass of the base supported polymer. The base supported copolymer cogranule is then pulverised. Pulverisation can be carried out by any method of granulation, by revolving drum, dish or rapid mixer.

Optional detergent ingredients In addition to the essential ingredients described herein above, the compositions of the invention may be formulated to comprise detergent ingredients, preferably selected from bleaching agents, bleach activators, sources of alkalinity, heavy metal ion sequestrants, crystal growth inhibitors, enzymes, organic polymeric compounds, suds suppressors, corrosion inhibitors and fillers.

Machine dishwashing compositions The compositions herein are adapted for use in a machine dishwashing method. Such compositions are formulated to enable the removal of, typically food based, soils and stains from soiled tableware under the conditions present in a machine dishwasher. Typically the compositions are low foaming, preferably containing only low levels of low-foaming surfactants.

Oxygen-releasing bleaching svstem Optionally, the detergent compositions may contain an oxygen-releasing bleaching system. In one preferred aspect the bleaching system contains a hydrogen peroxide source and an organic peroxyacid bleach precursor compound. The production of the organic peroxyacid occurs by an in situ reaction of the precursor with a source of hydrogen peroxide. Preferred sources of hydrogen peroxide include inorganic perhydrate bleaches. In an alternative preferred aspect a preformed organic peroxyacid is incorporated directly into the composition. Compositions containing mixtures of a hydrogen peroxide source and organic peroxyacid precursor in combination with a preformed organic peroxyacid are also envisaged.

Inorganic perhydrate bleaches The compositions may include a hydrogen peroxide source, as an oxygenreleasing bleach. Suitable hydrogen peroxide sources include the inorganic perhydrate salts.

The inorganic perhydrate salts are normally incorporated in the form of the sodium salt at a level of from 1% to 40% by weight, more preferably from 2% to 30% by weight and most preferably from 5% to 25% by weight of the compositions.

Examples of inorganic perhydrate salts include perborate, percarbonate, perphosphate, persulfate and persilicate salts. The inorganic perhydrate salts are normally the alkali metal salts. The inorganic perhydrate salt may be included as the crystalline solid without additional protection. For certain perhydrate salts however, the preferred executions of such granular compositions utilize a coated form of the material which provides better storage stability for the perhydrate salt in the granular product.

Sodium perborate can be in the form of the monohydrate of nominal formula NaBO2H202 or the tetrahydrate NaBO2H202.3H2O.

Alkali metal percarbonates, particularly sodium percarbonate are preferred perhydrates for inclusion in compositions in accordance with the invention.

Sodium percarbonate is an addition compound having a formula corresponding to 2Na2C03.3H202, and is available commercially as a crystalline solid. Sodium percarbonate, being a hydrogen peroxide addition compound tends on dissolution to release the hydrogen peroxide quite rapidly which can increase the tendency for localized high bleach concentrations to arise. The percarbonate is most preferably incorporated into such compositions in a coated form which provides in product stability.

A suitable coating material providing in product stability comprises mixed salt of a water soluble alkali metal sulphate and carbonate. Such coatings together with coating processes have previously been described in GB1,466,799, granted to Interox on 9th March 1977. The weight ratio of the mixed salt coating material to percarbonate lies in the range from 1: 200 to 1: 4, more preferably from 1: 99 to 1 : 9, and most preferably from 1: 49 to 1 : 19. 19 Preferably, the mixed salt is of sodium sulphate and sodium carbonate which has the general formula Na2S04.n.Na2C03 wherein n is from 0.1 to 3, preferably n is from 0.3 to 1.0 and most preferably n is from 0.2 to 0.5.

Other coatings which contain silicate (alone or with borate salts or boric acids or other inorganics), waxes, oils, fatty soaps can also be used advantageously within the present invention.

Potassium peroxyinonopersulfate is another inorganic perhydrate salt of utility in the compositions herein.

Peroxvacid bleach precursor Peroxyacid bleach precursors are compounds which react with hydrogen peroxide in a perhydrolysis reaction to produce a peroxyacid. Generally peroxyacid bleach precursors may be represented as

where L is a leaving group and X is essentially any functionality, such that on perhydrolysis the structure of the peroxyacid produced is

Peroxyacid bleach precursor compounds are preferably incorporated at a level of from 0.5% to 20% by weight, more preferably from 1% to 10% by weight, most preferably from 1.5% to 5% by weight of the compositions.

Suitable peroxyacid bleach precursor compounds typically contain one or more N- or O-acyl groups, which precursors can be selected from a wide range of classes. Suitable classes include anhydrides, esters, imides, lactams and acylated derivatives of imidazoles and oximes. Examples of useful materials within these classes are disclosed in GB-A-1 586789. Suitable esters are disclosed in GB-A-836988, 864798, 1147871, 2143231 and EP A-0170386.

Leaving groups The leaving group, hereinafter L group, must be sufficiently reactive for the perhydrolysis reaction to occur within the optimum time frame (e.g., a wash cycle). However, if L is too reactive, this activator will be difficult to stabilize for use in a bleaching composition.

Preferred L groups are selected from the group consisting of:

and mixtures thereof, wherein R1 is an alkyl, aryl, or alkaryl group containing from 1 to 14 carbon atoms, R3 is an alkyl chain containing from 1 to 8 carbon atoms, R4 is H or R3, and Y is H or a solubilizing group. Any of R1, R3 and R4 may be substituted by essentially any functional group including, for example alkyl, hydroxy, alkoxy, halogen, amine, nitrosyl, amide and ammonium or alkyl ammonium groups The preferred solubilizing Coups are -SO3M+, -CO-M,-SO 'M+ -N+(R3) and O < -N(R )3 and most preferably -SO3M+ and -CO2+ wherein This an alkyl chain containing from 1 to 4 carbon atoms, M is a cation which provides solubility to the bleach activator and X is an anion which provides solubility to the bleach activator. Preferably, M is an alkali metal, ammonium or substituted ammonium cation, with sodium and potassium being most preferred, and X is a halide, hydroxide, methyl sulfate or acetate union.

Perbenzoic acid precursor Perbenzoic acid precursor compounds provide perbenzoic acid on perhydrolysis.

Suitable O-acylated perbenzoic acid precursor compounds include the substituted and unsubstituted benzoyl oxybenzene sulfonates, including for example benzoyl oxybenzene sulfonate:

Also suitable are the benzoylation products of sorbitol, glucose, and all saccharides with benzoylating agents, including for example:

Ac = COCH3; Bz = Benzoyl Perbenzoic acid precursor compounds of the imide type include N-benzoyl succinimide, tetrabenzoyl ethylene diamine and the N-benzoyl substituted ureas. Suitable imidazole type perbenzoic acid precursors include N-benzoyl imidazole and N-benzoyl benzimidazole and other useful N-acyl groupcontaining perbenzoic acid precursors include N-benzoyl pyrrolidone, dibenzoyl taurine and benzoyl pyroglutamic acid.

Other perbenzoic acid precursors include the benzoyl diacyl peroxides, the benzoyl tetraacyl peroxides, and the compound having the formula:

Phthalic anhydride is another suitable perbenzoic acid precursor compound herein:

Suitable N-acylated lactam perbenzoic acid precursors have the formula:

wherein n is from 0 to 8, preferably from 0 to 2, and R6 is a benzoyl group.

Perbenzoic acid derivative precursors Perbenzoic acid derivative precursors provide substituted perbenzoic acids on perhydrolysis.

Suitable substituted perbenzoic acid derivative precursors include any of the herein disclosed perbenzoic precursors in which the betizoyl group is substituted by essentially any non-positively charged (ie; non-cationic) functional group including, for example alkyl, hydroxy, alkoxy, halogen, amine, nitrosyl and amide groups.

A preferred class of substituted perbenzoic acid precursor compounds are the amide substituted compounds of the following general formulae:

wherein R1 is an aryl or alkaryl group with from 1 to 14 carbon atoms, R2 is an arylene, or alkarylene group containing from 1 to 14 carbon atoms, and R5 is H or an alkyl, aryl, or alkaryl group containing 1 to 10 carbon atoms and L can be essentially any leaving group. R1 preferably contains from 6 to 12 carbon atoms. R2 preferably contains from 4 to 8 carbon atoms. R1 may be aryl, substituted aryl or alkylaryl containing branching, substitution, or both and may be sourced from either synthetic sources or natural sources including for example, tallow fat. Analogous structural variations are permissible for R2.The substitution can include alkyl, aryl, halogen, nitrogen, sulphur and other typical substituent groups or organic compounds.

R5 is preferably H or methyl. R1 and R5 should not contain more than 18 carbon atoms in total. Amide substituted bleach activator compounds of this type are described in EP-A-0170386.

Cationic peroxvacid precursors Cationic peroxyacid precursor compounds produce cationic peroxyacids on perhydrolysis.

Typically, cationic peroxyacid precursors are formed by substituting the peroxyacid part of a suitable peroxyacid precursor compound with a positively charged functional group, such as an ammonium or alkyl ammmonium group, preferably an ethyl or methyl ammonium group.

Cationic peroxyacid precursors are typically present in the compositions as a salt with a suitable anion, such as for example a halide ion or a methyl sulfate ion.

The peroxyacid precursor compound to be so cationically substituted may be a perbenzoic acid, or substituted derivative thereof, precursor compound as described hereinbefore. Alternatively, the peroxyacid precursor compound may be an alkyl percarboxylic acid precursor compound or an amide substituted alkyl peroxyacid precursor as described hereinafter Cationic peroxyacid precursors are described in U.S. Patents 4,904,406; 4,751,015; 4,988,451; 4,397,757; 5,269,962; 5,127,852; 5,093,022; 5,106,528; U.K. 1,382,594; EP 475,512, 458,396 and 284,292; and in JP 87-318,332.

Examples of preferred cationic peroxyacid precursors are described in UK Patent Application No. 9407944.9 (attorney's docket no. CM642F) and US Patent Application Nos. 08/298903, 08/298650, 08/298904 and 08/298906 (attorney's docket no.s 5413 to 5416).

Suitable cationic peroxyacid precursors include any of the ammonium or alkyl ammonium substituted alkyl or berizoyl oxybenzene sulfonates, Nacylated caprolactams, and monobenzoyltetraacetyl glucose benzoyl peroxides.

A preferred cationically substituted berizoyl oxybenzene sulfonate is the 4 (trimethyl ammonium) methyl derivative of benzoyl oxybenzene sulfonate:

A preferred cationically substituted alkyl oxybenzene sulfonate has the formula:

Preferred cationic peroxyacid precursors of the N-acylated caprolactam class include the trialkyl ammonium methylene berizoyl caprolactams, particularly trimethyl ammonium methylene benzoyl caprolactam:

Other preferred cationic peroxyacid precursors of the N-acylated caprolactam class include the trialkyl ammonium methylene alkyl caprolactams:

where n is from 0 to 12, particularly from 1 to 5.

Another preferred cationic peroxyacid precursor is 2-(N,N,N-trimethyl ammonium) ethyl sodium 4-sulphophenyl carbonate chloride.

Alkyl percarboxylic acid bleach precursors Alkyl percarboxylic acid bleach precursors form percarboxylic acids on perhydrolysis. Preferred precursors of this type provide peracetic acid on perhydrolysis.

Preferred alkyl percarboxylic precursor compounds of the imide type include the N-,N,N1N1 tetra acetylated alkylene diamines wherein the alkylene group contains from 1 to 6 carbon atoms, particularly those compounds in which the alkylene group contains 1, 2 and 6 carbon atoms. Tetraacetyl ethylene diamine (TAED) is particularly preferred.

Other preferred alkyl percarboxylic acid precursors include sodium 3,5,5-trimethyl hexanoyloxybenzene sulfonate (iso-NOBS), sodium nonanoyloxybenzene sulfonate (NOBS), sodium acetoxybenzene sulfonate (ABS) and pentaacetyl glucose.

Amide substituted alkyl Deroxvacid precursors Amide substituted alkyl peroxyacid precursor compounds are also suitable, including those of the following general formulae:

wherein R1 is an alkyl group with from 1 to 14 carbon atoms, R2 is an alkylene group containing from 1 to 14 carbon atoms, and R5 is H or an alkyl group containing 1 to 10 carbon atoms and L can be essentially any leaving group. R1 preferably contains from 6 to 12 carbon atoms. R2 preferably contains from 4 to 8 carbon atoms. R1 may be straight chain or branched alkyl containing branching, substitution, or both and may be sourced from either synthetic sources or natural sources including for example, tallow fat. Analogous structural variations are permissible for R2.

The substitution can include alkyl, halogen, nitrogen, sulphur and other typical substituent groups or organic compounds. R5 is preferably H or methyl. R1 and R5 should not contain more than 18 carbon atoms in total.

Amide substituted bleach activator compounds of this type are described in EP-A-01 70386.

Benzoxazin organic peroxvacid precursors Also suitable are precursor compounds of the benzoxazin-type, as disclosed for example in EP-A-332,294 and EP-AX82,807, particularly those having the formula:

including the substituted benzoxazins of the type

wherein R1 is H, allcyl, alkaryl, aryl, arylalkyl, and wherein R2, R3, R4, and R5 may be the same or different substituents selected from H, halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkyl amino, COOR6 (wherein R6 is H or an alkyl group) and carbonyl functions.

An especially preferred precursor of the benzoxazin-type is:

Preformed organic peroxyacid The organic peroxyacid bleaching system may contain, in addition to, or as an alternative to, an organic peroxyacid bleach precursor compound, a preformed organic peroxyacid , typically at a level of from 0.5% to 25% by weight, more preferably from 1% to 10% by weight ofthe composition.

A preferred class of organic peroxyacid compounds are the amide substituted compounds of the following general formulae:

wherein R1 is an alkyl, aryl or alkaryl group with from 1 to 14 carbon atoms, R2 is an alkylene, arylene, and alkarylene group containing from 1 to 14 carbon atoms, and R5 is H or an alkyl, aryl, or alkaryl group containing 1 to 10 carbon atoms. R1 preferably contains from 6 to 12 carbon atoms. R2 preferably contains from 4 to 8 carbon atoms. R1 may be straight chain or branched alkyl, substituted aryl or alkylaryl containing branching, substitution, or both and may be sourced from either synthetic sources or natural sources including for example, tallow fat. Analogous structural variations are permissible for R2. The substitution can include alkyl, aryl, halogen, nitrogen, sulphur and other typical substituent groups or organic compounds.R5 is preferably H or methyl. R1 and R5 should not contain more than 18 carbon atoms in total. Amide substituted organic peroxyacid compounds of this type are described in EP-A-0170386.

Other organic peroxyacids include diacyl and tetraacylperoxides, especially diperoxydodecanedioc acid, diperoxytetradecanedioc acid, and diperoxyhexadecanedioc acid. Dibenzoyl peroxide is a preferred organic peroxyacid herein. Mono- and diperazelaic acid, mono- and diperbrassylic acid, and N-phthaloylaminoperoxicaproic acid are also suitable herein.

Chlorine bleaching system Suitable chlorine bleaches include the alkali metal hypochlorites and chlorinated cyanuric acid salts. Water soluble dichlorocyanurates such as sodium or potassium dichloroisocyanurate are preferred.

Heaw metal ion seauestztnt The detergent compositions of the invention preferably contain as an optional component a heavy metal ion sequestrant. By heavy metal ion sequestrant it is meant herein components which act to sequester (chelate) heavy metal ions. These components may also have calcium and magnesium chelation capacity, but preferentially they show selectivity to binding heavy metal ions such as iron, manganese and copper.

Heavy metal ion sequestrants are generally present at a level of from 0.005% to 20%, preferably from 0.1% to 10%, more preferably from 0.25% to 7.5% and most preferably from 0.5% to 5% by weight of the compositions.

Heavy metal ion sequestrants, which are acidic in nature, having for example phosphonic acid or carboxylic acid functionalities, may be present either in their acid form or as a complex/salt with a suitable counter cation such as an alkali or alkaline metal ion, ammonium, or substituted ammonium ion, or any mixtures thereof. Preferably any salts/complexes are water soluble. The molar ratio of said counter cation to the heavy metal ion sequestrant is preferably at least 1:1.

Suitable heavy metal ion sequestrants for use herein include organic phosphonates, such as the amino alkylene poly (alkylene phosphonates), alkali metal ethane 1-hydroxy disphosphonates and nitrilo trimethylene phosphonates. Preferred among the above species are diethylene triamine penta (methylene phosphonate), ethylene diamine tri (methylene phosphonate) hexamethylene diamine tetra (methylene phosphonate) and hydroxy-ethylene 1,1 diphosphonate.

Other suitable heavy metal ion sequestrant for use herein include nitrilotriacetic acid and polyaminocarboxylic acids such as ethylenediaminotetracetic acid, ethylenetriamine pentacetic acid, ethylenediamine disuccinic acid, ethylenediamine diglutaric acid, 2hydroxypropylenediamine disuccinic acid or any salts thereof.

Especially preferred is ethylenediamine-N,N'-disuccmic acid (EDDS) or the alkali metal, alkaline earth metal, ammonium, or substituted ammonium salts thereof, or mixtures thereof. Preferred EDDS compounds are the free acid form and the sodium or magnesium salt or complex thereof.

Crvstal growth inhibitor component The detergent compositions preferably contain a crystal growth inhibitor component, preferably an organodiphosphonic acid component, incorporated preferably at a level of from 0.01% to 5%, more preferably from 0.1% to 2% by weight of the compositions.

By organo diphosphonic acid it is meant herein an organo diphosphonic acid which does not contain nitrogen as part of its chemical structure. This definition therefore excludes the organo aminophosphonates, which however may be included in compositions of the invention as heavy metal ion sequestrant components.

The organo diphosphonic acid is preferably a C 1 -C4 diphosphonic acid, more preferably a C2 diphosphonic acid, such as ethylene diphosphonic acid, or most preferably ethane 1 -hydroxy- 1,1 -diphosphonic acid (HEDP) and may be present in partially or fully ionized form, particularly as a salt or complex.

Enzyme Another optional ingredient useful in the compositions is one or more enzymes. Preferred enzymatic materials include the commercially available lipases, amylases, neutral and alkaline proteases, esterases, cellulases, pectinases, lactases and peroxidases conventionally incorporated into detergent compositions. Suitable enzymes are discussed in US Patents 3,519,570 and 3,533,139.

Preferred commercially available protease enzymes include those sold under the tradenames Alcalase, Savinase, Primase, Durazym, and Esperase by Novo Industries A/S (Denmark), those sold under the tradename Maxatase, Maxacal and Maxapem by Gist-Brocades, those sold by Genencor International, and those sold under the tradename Opticlean and Optimase by Solvay Enzymes. Protease enzyme may be incorporated into the compositions in accordance with the invention at a level of from 0.0001% to 4% active enzyme by weight of the composition.

Preferred amylases include, for example, amylases obtained from a special strain of B licheniformis, described in more detail in GB-1,269,839 (Novo). Preferred commercially available amylases include for example, those sold under the tradename LE17 by Novo Industries A/S. Amylase enzyme may be incorporated into the composition in accordance with the invention at a level of from 0.0001% to 2% active enzyme by weight of the composition.

Lipolytic enzyme (lipase) may be present at levels of active lipolytic enzyme of from 0.0001% to 2% by weight, preferably 0.001% to 1% by weight, most preferably from 0.001% to 0.5% by weight of the compositions. The lipase may be fungal or bacterial in origin. Lipase from chemically or genetically modified mutants of these strains are also useful herein. A preferred lipase is described in Granted European Patent, EP-B-0218272.

An especially preferred lipase herein is obtained by cloning the gene from Humicola lanuginosa and expressing the gene in Aspergillus orvza, as host, as described in European Patent Application, EP-A-0258 068, which is commercially available from Novo Industri A/S, Bagsvaerd, Denmark, under the trade name Lipolase. This lipase is also described in U.S. Patent 4,810,414, Huge-Jensen et al, issued March 7, 1989.

Alkalinity system The compositions may alternatively contain an alkalinity system containing non polymerised sodium silicate having an SiO2 : Na2O ratio of from 1.8 to 3.0, preferably from 1.8 to 2.4, most preferably 2.0, present preferably at a level of less than 20%, preferably from 1% to 15%, most preferably from 3% to 12% by weight of SiO2. The alkali metal silicate may be in the form of either the anhydrous salt or a hydrated salt.

The alkalinity system may also contain sodium metasilicate, present at a level of at least 0.4% SiO2 by weight. Sodium metasilicate has a nominal SiO2 : Na2O ratio of 1.0. The weight ratio of said sodium silicate to said sodium metasilicate, measured as SiO2, is preferably from 50:1 to 5:4, more preferably from 15:1 to 2:1, most preferably from 10:1 to 5:2.

Organic volymeric compound Organic polymeric compounds may be added as preferred components of the compositions in accord with the invention. By organic polymeric compound it is meant essentially any polymeric organic compound commonly used as dispersants, and anti-redeposition and soil suspension agents in detergent compositions.

Organic polymeric compound is typically incorporated in the detergent compositions of the invention at a level of from 0. 1% to 30%, preferably from 0.5% to 15%, most preferably from 1% to 10% by weight of the compositions.

Examples of organic polymeric compounds include the water soluble organic homo- or co-polymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxyl radicals separated from each other by not more than two carbon atoms. Polymers of the latter type are disclosed in GB-A-1,596,756. Examples of such salts are polyacrylates of molecular weight 2000-10000 and their copolymers with any suitable other monomer units including modified acrylic, flimaric, maleic, itaconic, aconitic, mesaconic, citraconic and methylenemalonic acid or their salts, maleic anhydride, acrylamide, alkylene, vinylmethyl ether, styrene and any mixtures thereof. Preferred are the copolymers of acrylic acid and maleic anhydride having a molecular weight of from 20,000 to 100,000.

Preferred commercially available acrylic acid containing polymers having a molecular weight below 15,000 include those sold under the tradename Sokalan PA30, PA20, PA15, PAlO and Sokalan CP10 by BASF GmbH, and those sold under the tradename Acusol 45N by Rohm and Haas.

Preferred acrylic acid containing copolymers include those which contain as monomer units: a) from 90% to 10%, preferably from 80% to 20% by weight acrylic acid or its salts and b) from 10% to 90%, preferably from 20% to 80% by weight of a substituted acrylic monomer or its salts having the general formula -[CR2-CR1(CO-O-R3)]- wherein at least one of the substituents R1, R2 or R3, preferably R1 or R2 is a 1 to 4 carbon alkyl or hydroxyalkyl group, R1 or R2 can be a hydrogen and R3 can be a hydrogen or alkali metal salt. Most preferred is a substituted acrylic monomer wherein R1 is methyl, R2 is hydrogen (i.e. a methacrylic acid monomer).

The most preferred copolymer of this type has a molecular weight of 3500 and contains 60% to 80% by weight of acrylic acid and 40% to 20% by weight of methacrylic acid.

The polyamino compounds are useful herein including those derived from aspartic acid such as those disclosed in EP-A-305282, EP-A-305283 and EP-A-35 1629.

Lime soap dispersant compound The compositions of the invention may contain a lime soap dispersant compound, preferably present at a level of from 0.1% to 40% by weight, more preferably 1% to 20% by weight, most preferably from 2% to 10% by weight of the compositions.

A lime soap dispersant is a material that prevents the precipitation of alkali metal, ammonium or amine salts of fatty acids by calcium or magnesium ions. Preferred lime soap disperant compounds are disclosed in PCT Application No. W093/08877 (attorney's docket no. CM466M).

Suds suppressing system The compositions of the invention, when formulated for use in machine washing compositions, preferably comprise a suds suppressing system present at a level of from 0.01% to 15%, preferably from 0.05% to 10%, most preferably from 0.1% to 5% by weight ofthe composition.

Suitable suds suppressing systems for use herein may comprise essentially any known antifoam compound, including, for example silicone antifoam compounds, 2-alkyl and alcanol antifoam compounds. Preferred suds suppressing systems and antifoam compounds are disclosed in PCT Application No. W093/08876 (attorney's docket no. CM465M) and copending European Application No. 93870132.3 (attorney's docket no.

CM562F).

Polvmeric dve transfer inhibiting agents The compositions herein may also comprise from 0.01% to 10 %, preferably from 0.05% to 0.5% by weight of polymeric dye transfer inhibiting agents.

The polymeric dye transfer inhibiting agents are preferably selected from polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and Nvinylimidazole, polyvinylpyrrolidonepolymers or combinations thereof.

Corrosion inhibitor The compositions may contain corrosion inhibitors such as benzotriazole and paraffin. Suitable corrosion inhibitors are described in PCT Application No. W094/07981 and copending European Application No. EP 93202095.1 (attorney's docket no. CM571F).

pH of the compositions The present compositions are preferably not formulated to have an unduly high pH, in preference having a pH measured as a 1 % solution in distilled water of from 8.0 to 12.0, more preferably from 9.0 to 11.8, most preferably from 9.5 to 11.5.

Form of the compositions The compositions of the invention can be formulated in any desirable form such as powders, granulates, pastes, liquids, gels and tablets, granular forms being preferred.

The bulk density of the granular detergent compositions in accordance with the present invention is typically of at least 650 g/litre, more usually at least 700 g/litre and more preferably from 800 goitre to 1200 g/litre.

The particle size of the components of granular compositions in accordance with the invention should preferably be such that no more that 5% of particles are greater than 1.4mm in diameter and not more than 5% of particles are less than 0.15mm in diameter.

Generally, if the compositions are in liquid form the liquid should be thixotropic (ie; exhibit high viscosity when subjected to low stress and lower viscosity when subjected to high stress), or at least have very high viscosity, for example, of from 1,000 to 10,000,000 centipoise.

Machine dishwashing method Any suitable methods for machine washing or cleaning soiled tableware, particularly soiled silverware are envisaged.

A preferred machine dishwashing method comprises treating soiled articles selected from crockery, glassware, hollowware, silverware and cutlery and mixtures thereof, with an aqueous liquid having dissolved or dispensed therein an effective amount of a machine dishwashing composition in accord with the invention. By an effective amount of the machine dishwashing composition it is meant from 8g to 60g of product dissolved or dispersed in a wash solution of volume from 3 to 10 litres, as are typical product dosages and wash solution volumes commonly employed in conventional machine dishwashing methods.

Nonionic C13-C15 mixed ethoxylated/propoxylated fatty alcohol with an average degree of ethoxylation of 3.8 and an average degree of propoxylation of 4.5 sold under the tradename Plurafac LF404 by BASF Gmbh (low foaming) Silicate : Amorphous Sodium Silicate (SiO2:Na20 ratio = 2.0) Carbonate : Anhydrous sodium carbonate Phosphate : Sodium tripolyphosphate 480N : Random copolymer 3:7 acrylic/methacrylic acid, average molecular weight about 3,500 Citrate : Tri-sodium citrate dihydrate PB 1 Anydrous sodium perborate monohydrate TAED : Tetraacetyl ethylene diamine DETPMP Diethylene triamine penta (methylene phosphonic acid), marketed by Monsanto under the tradename Dequest 2060 HEDP :Ethane 1-hydroxy-1,1-diphosphonic acid Base supported copolymer Cogranule containing 53.3% sodium carbonate, 28.1% copolymer of sodium (2.1 ratio) silicate and potassium methyl siliconate present at a weight ratio of 99:1, and 18.6% water.

Paraffin : Paraffin oil sold under the tradename Winog 70 by Wintershall.

Protease : Proteolytic enzyme sold under the tradename Savinase by Novo Industries A/S (approx 2% enzyme activity).

BSA : Amylolytic enzyme sold under the tradename LE17 by Novo Industries A/S (approx 1% enzyme activity) Sulphate : Anhydrous sodium sulphate.

pH : Measured as a 1% solution in distilled water at 20"C.

Example 1 The following machine dishwashing compositions were prepared (parts by weight). Compositions A is a comparative composition, compositions B to G are in accord with the invention.

A B C D E F G Citrate 15.0 15.0 15.0 15.0 15.0 15 0 480N 6.0 6.0 6.0 6.0 60 6.0 0 Carbonate 20.4 Phosphate - - - - - 18.0 Silicate (as 12.2 1 raw material) PB1(AvO) 1.5 1.2 1.5 1.5 1.5 2.2 1.2

TAED 2.2 2.2 2.2 - - 2.2 2.2 Paraffin 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Base - 39.3 39.3 39.3 38.0 36.0 40.0 supported copolymer 1 er Protease 0.04 0.04 0.04 0.04 0.04 0.04 0.04 BSA 0.03 0.03 0.03 0.03 0.03 0.03 0.03 DETPMP 0.13 0.13 0.13 0.13 0.13 0.13 HEDP 1.0 1.0 1.0 1.0 1.0 1.0 Nonionic 2.0 2.0 2.0 2.0 2.0 2.0 1.5 Sulphate 20.4 14.6 12.7 15.1 16.3 11.5 8.1 mise inc moisture to balance pH (1% 11.0 11.0 11.0 10.7 10.7 10.7 11.0 solution) ComDarative testingzelassware o rotection.

The glass protection performance of Composition B, in accord with the invention was compared to that of comparative Composition A using the following five hundred- cycle test procedure.

A set of six 200ml household glasses were placed in the upper rack of each of five Bosch Siemens SMS6032 (tradename) machine dishwashers. The 65"C wash setting was selected, the wash process comprising main wash and rinse cycles. 26 grams of each composition was employed for each complete wash process. The feed water hardness was 8" Clark Hardness (114.3 ppm CaC03 equivalent). Dishwasher salt was employed to reduce the in wash water hardness to about 2" Clark Hardness (28.6 ppm CaC03 equivalent). Each set of six glasses was washed one hundred times in each of the five machines (ie: 500 complete wash + rinse cycles).

At the end of the final wash process the glasses were removed and graded for appearance, in particular, permanent clouding The grading was performed by 4 expert graders and the results averaged for each of the five sets of six glasses. Grading was through visual inspection according to the following scale: 1 = no permanent clouding 2 = very slight permanent clouding (visible on close inspection) 3 = noticeable permanent clouding 4 = very noticeable permanent clouding 5 = severe permanent clouding The results were as follows: (average of the 4 gradings from the panellists)

A B 2.0 l 1.5 The glass appearance profile of Compositions B is seen to be better than that of related comparative Composition A Comparative testine - elassware pattern protection The glass pattern protection performance of Compositions B, in accord with the invention was compared to that of comparative Composition A using the following five hundred-cycle test procedure.

A set of six 200ml household glasses having various overlaid glass patterns, including representations of fruits, flowers and cartoon characters, were placed in the upper rack of each of five Bosch Siemens SMS6032 (tradename) machine dishwashers. The 65"C wash setting was selected, the wash process comprising main wash and rinse cycles. 26 grams of each composition was employed for each complete wash process. The feed water hardness was 8" Clark Hardness (114.3 ppm CaC03 equivalent).

Dishwasher salt was employed to reduce the in wash water hardness to about 2" Clark Hardness (28.6 ppm CaC03 equivalent). Each set of six glasses was washed one hundred times in each of the five machines (ie: 500 complete wash + rinse cycles).

At the end of the final wash process the glasses were removed and then graded for loss of pattern. The grading was performed by 4 expert graders and the results averaged for each of the five sets of six glasses. Grading was through visual inspection according to the following scale: 1 = no pattern loss 2 = very slight pattern loss (visible on close inspection) 3 = noticeable pattern loss 4 = very noticeable pattern loss 5 = severe pattern loss Results were as follows : (average of the 4 gradings from the panellists)

A | B 3.0 2.0 The pattern protection profile of Compositions B is seen to be better than that of related comparative Composition A.

ComParative testine - chinaware pattern orotection The china pattern protection performance of Compositions B, in accord with the invention was compared to that of comparative Composition A using the following five hundred-cycle test procedure.

A set of six 25cm household china plates having various overlaid patterns, including representations of fruits and flowers, were placed in the upper rack of each of five Bosch Siemens SMS6032 (tradename) machine dishwashers.

The 65"C wash setting was selected, the wash process comprising main wash and rinse cycles. 26 grams of each composition was employed for each complete wash process. The feed water hardness was 8" Clark Hardness (114.3 ppm CaCO3 equivalent). Dishwasher salt was employed to reduce the in wash water hardness to about 2" Clark Hardness (28.6 ppm CaC03 equivalent). Each set of six plates was washed one hundred times in each of the five machines (ie: 500 complete wash + rinse cycles).

At the end of the final wash process the plates were removed and then graded for loss of pattern. The grading was performed by 4 expert graders and the results averaged for each of the five sets of six plates. Grading was through visual inspection according to the following scale: 1 = no pattern loss 2 = very slight pattern loss (visible on close inspection) 3 = noticeable pattern loss 4 = very noticeable pattern loss 5 = severe pattern loss Results were as follows : (average of the 4 gradings from the panellists)

A A I B 2.5 1 1.5 The china pattern protection profile of Compositions B is seen to be better than that of related comparative Composition A.

Claims (12)

Claims

1. A detergent composition, adapted for use in a dishwashing method, containing a) a detergent component selected from the group consisting of a surfactant, a water-soluble builder compound and any mixtures thereof; and b) a base supported copolymer comprising a copolymer adsorbed and/or absorbed onto a base of solid water-soluble inorganic compound, characterized in that said copolymer is obtainable by condensation polymerisation of a) an ammonium or alkali metal silicate of molar ratio Si20/M20 of from 0.5 to 4, where the symbol M represents an ammonium or an alkali metal cation; and b) an organic silicon compound, selected from the group consisting of (i) alkali metal siliconates of formula RnSi(O)p(OH)4-n-p (ii) alkoxysilanes of formula RnSi(OR')4,n and any mixtures thereof where, R represents a hydrocarbon group, containing from 1 to 20 carbon atoms, which may optionally contain one or more nitrogen, oxygen or halogen atom; M represents an ammonium or alkali metal cation (n + p) is a number of less than or equal to 4, where n is between 1 and 3, and p is greater than or equal to 1 R' represents a linear or branched chain alkyl group containing between 1 and 6 carbon atoms; wherein the ammonium or alkali metal silicate and organic silicon compound components of the copolymer are present such that the weight ratio of Si present as the organic silicon compound component to the total Si content of the copolymer is from 0.0002:1 to 0.05:1, and wherein the base supported copolymer has a water content of between 10 to 35% by weight.

2. Detergent composition according to claim 1 wherein the ammonium or alkali metal silicate and organic silicon compound components of the copolymer are present such that the weight ratio of Si present as the organic silicon compound component to the total Si content of the copolymer is from 0.002:1 to 0.02:1, and wherein the base support material is present at a level of from 30 to 75% by weight of the base supported copolymer, and wherein the base supported copolymer has a water content of 14 to 25% by weight.

3. A detergent composition according to either of claims I or 2 wherein said molar ratio Si2O/M2O is from 1.2 to 3.5.

4. A detergent composition according to any of claims 1 to 3 where the dry weight ratio of solid water-soluble inorganic compound to silicate compound is 60:40 to 70:30.

5. A detergent composition according to any of claims 1 to 4 wherein R' is a methyl or ethyl group.

6. A detergent composition according to any of claims 1 to 5 wherein said water-soluble inorganic compound is a carbonate or bicarbonate.

7. Detergent composition according to any of claims 1 to 6, wherein said alkali metal silicate is sodium silicate.

8. Detergent composition according to any of claims 1 to 7, wherein said alkali metal siliconates are selected from the group consisting of: sodium or potassium methylsiliconates of formula CH3 Si (ONa)3 or CH3 Si(OK)3, sodium or potassium propylsiliconates of formula C3H7 Si(ONa)3 or C3H7 Si(OK)3 sodium or potassium butylsiliconates of formula C4H9 Si(ONa)3 or C4H9 Si(OK)3, sodium or potassium hexylsiliconates of formula C6H 13 Si(ONa)3 or C6H 13 Si(OK)3 sodium or potassium octylsiliconates of formula C8H17 Si(ONa)3 or C8H17 Si(OK)3, sodium or potassium dimethylsiliconates of formula (CH3)2 Si (ONa)2 or (CH3)2 Si (OK)2, sodium or potassium methylpropylsiliconates of formula (CH3)(C3H7)Si(ONa)2 or (CH3)(C3H7)Si(OK)2, sodium or potassium methylbutylsiliconates of formula methylhexylsiliconates of formula (CH3)(C6H1 3)Si(ONa)2 or (CH3 )(C6H 13 )Si(OK)2, sodium or potassium methyloctylsiliconates of formula (CH3)(CgH17)Si(ONa)2 or (CH3)(C8H1 7)Si(OK)2 and any mixtures thereof; and said alkoxysilanes are selected from the group consisting of;; methyltrimethoxysilane of formula CH3 Si (OMe)3, methyltriethoxysilane of formula CH3 Si (OEt)3, octyltrimethoxysilane of formula C8H17 Si (OMe)3, octyltriethoxysilane of formula C8H17 Si (OEt)3, diethylenediaminetriethoxysilane of formula H2N-(CH2)2-NH (CH2)2-Si(OEt)3 dimethyldimethoxysilane of formula (CH3)2 Si(OMe)2 trimethylmethoxysilane of formula (CM3 )3 Si(OMe), dimethyldiethoxysilane of formula (CH3)2 Si(OEt)2 trimethylethoxysilane of formula (CH3)3 Si(OEt) and any mixtures thereof.

9. Detergent composition according to any of claims 1 to 9, containing an additive selected from the group consisting of bleaching agents, bleach activators, sources of alkalinity, heavy metal ion sequestrants, crystal growth inhibitors, enzymes, organic polymeric compounds, suds suppressors, corrosion inhibitors and fillers.

10. A process for the preparation of a detergent composition according to any of claims 1 to 10, comprising the steps of: (i) mixing the solid water-soluble inorganic compound with an aqueous solution of copolymer, (ii) drying the resultant mixture to a moisture level of 10 to 35% at a temperature of between 20 and 1 600C, (iii) combining the base supported copolymer formed by steps (i) and (ii) with the detergent components.

11. Use of the detergent composition according to any of claims 1 to 9, in a machine dishwashing method.

12. Use of a base supported copolymer according to claim 1, in a method of machine washing glassware and chinaware, to enable the formation of a uniform silicate protective layer on the surface of said glassware and chinaware.