GB2288607A - Detergent Compositions Containing Diamine Tetracarboxylic Acid Or Salts Thereof - Google Patents

Abstract

The use of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylenediamine disuccinic acid (HPDDS) or mixtures thereof in a detergent composition for reducing enamel loss and corrosion during a washing machine process in which siliceous surfaces of the machine or of articles washed therein are exposed to the detergent liquor is disclosed. The use of the chelant allows decreased amounts of corrosion inhibitor to be used.

Description

DETERGENT COMPOSITIONS CONTAINING DIAMINE TETRACARBOXYLIC ACID OR SALTS THEREOF M.C.ADDISON G. M.BAILLELY G.M. BASTON F.S.MACBEATH FIELD OF THE INVENTION The present invention relates to detergent compositions containing diamine tetracarboxylate chelants.

More particularly, the present invention relates to the use of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2hydroxypropylenediamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, in a detergent composition for reducing enamel loss and corrosion during a washing machine process in which surfaces of the machine or of articles washed therein are exposed to the detergent liquor, said surfaces being selected from enamel surfaces and china surfaces.

Additionally, the present invention relates to a detergent composition comprising lower than conventional levels of corrosion inhibitors permitted by the unexpectable benefit of. the tetracarboxylate chelants for reducing enamel loss and corrosion.

BACKGROUND OF THE INVENTION Laundry detergent compositions containing the non-phosphorous chelant, ethylenediamine-N, N'-disuccinic acid (EDDS) are known in the art. For example, EP-A-0267 653 teaches that EDDS, when incorporated in such laundry compositions, assists in the removal of food, beverage and certain other organic stains from fabrics during the laundry process. It also teaches that EDDS may be used as a replacement for all or part of the phosphonate chelants currently used in many existing laundry products.

Furthermore, detergent compositions are disclosed in WO 94/03572, WO 94/03554 and WO 94/03553 which teach that EDDS with other components gives further enhanced stain removal benefits.

Dishwashing compositions with an oxygen bleach system containing EDDS are also known in the art, being disclosed in, for example, WO 92/09680. This disclosure teaches that EDDS when incorporated in the oxygen bleach system, assists in the removal of food and beverage stains from dishware.

In addition, analogues of EDDS such as ethylenediamine-N,N'-diglutaric acid (EDDG) and 2-hydroxypropylenediamine-N,N'-disuccinic acid (HPDDS) are disclosed in the commonly assigned U.S Patent Application No.08/026,884. This disclosure teaches that EDDG and HPDDS are useful components in detergent compositions for providing soil removal benefit.

The problem of corrosion of the metal and enamel surfaces of washing machines is also recognised in the art. Detergent compositions usually comprise some corrosion inhibitors such as silanes or silicates. Silicates are useful for reducing enamel loss. They are usually added as a dry mix ingredient, or as a structurant in the spray dried granules or in surfactant paste agglomerate which normally forms part of a laundry detergent composition. However, when added as a dry mix ingredient, high levels of soluble silicate are detrimental to the dispensing properties of the granular composition. When added as a structurant in a spray dried granule which incorporates aluminosilicate builder, high levels of silicate are detrimental to the solubility of the granular composition.

It has now been found that the partial or total replacement of a phosphonate chelant by a diamine tetracarboxylate chelant selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylenediamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof in a detergent composition, namely a reduction in the level of enamel loss and corrosion.Therefore, the detergent composition comprises lower than conventional level of corrosion inhibitors.

This unexpected benefit is provided by the use of diamine tetracarboxylate chelants in a detergent composition wherein said diamine tetracarboxylate chelants are selected from their racemate structure and isomeric structures.

It is an object of the invention to provide a detergent composition which reduces the enamel loss, provides a lower level of corrosion and encompasses further advantages.

SUMMARY OF THE INVENTION The present invention relates to the use of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylened iamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, in a detergent composition for reducing enamel loss and corrosion during a washing machine process in which siliceous surfaces of the machine or of articles washed therein are exposed to the detergent liquor.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the use of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylenediamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, in a detergent composition for reducing enamel loss and corrosion during a washing machine process in which siliceous surfaces of the machine or of articles washed therein are exposed to the detergent liquor.

For the present application, the term 'washing machine ' includes a laundry washing machine as well as a dishwashing machine.

Enamel or porcelain enamel is defined as a substantially vitreous or glassy inorganic coating bonded to metal by fusion at a temperature above 425"C. The porcelain enamelling protects against corrosion, and resists the attack of alkalis, acids and other chemicals. The major use of this material is represented in clothes washers and dishwashers.

For the purposes of the invention, china ware includes translucent, vitreous ceramic wares such as bone china, vitreous china and porcelain, as well as opaque nonvitreous ceramic wares such as stonewares and earthenwares.

For the purposes of the present invention, the term 'siliceous surface' includes an enamel surface and a china surface. Silica is the basic ingredient of enamel and chinaware and a siliceous or silica surface is defined as a surface containing silica.

The detergent compositions in which diamine tetracarboxylate chelants can be used include compositions which are to be used for cleaning substrates, such as fabrics, fibers, hard surfaces, skin , etc., for example hard surface cleaning compositions (with or without abrasives), laundry detergent compositions, automatic and non automatic dishwashing compositions.

Laundry detergent compositions useful in the present invention may have essentially any physical form. Preferred executions include granular compositions, especially concentrated granular laundry compositions, and heavy duty liquid compositions. Such detergent compositions also display further advantages.

Firstly, use of diamine tetracarboxylate chelants in accordance with the present invention permits the use of lower levels of expensive silane corrosion inhibitors in heavy duty liquid compositions.

Secondly, in heavy duty liquid compositions when using silicate as corrosion inhibitors instead of silane, the use of diamine tetracarboxylate chelants makes it easier to stabilise the composition at low/medium pH.

In heavy duty granular compositions formulated with a zeolite-based spray dried granule or a zeolite based agglomerate, the partial or total replacement of phosphonates by diamine tetracarboxylate chelants permits the reduction of silicate level and improves the product solubility. Where the heavy duty granular compositions are formulated with dry mixed amorphous silicate, the use of diamine tetracarboxylates permits the reduction of dry added silicate level and improves the product dispensing.

In automatic dishwashing (ADW) applications, the use of diamine tetracarboxylates in detergent compositions according to the present invention provides further advantages to those outlined above. The main additional advantage is to provide benefits against china corrosion.

Therefore, the level of china corrosion inhibitors such as silicate may be reduced whilst still maintaining excellent care of china exposed to multiple wash cycles in an ADW machine.

Furthermore, the reduction in the level of conventional china care ingredients such as silicate results in less deposition of the silicate onto glass surfaces providing another benefit of reducing damage to glass ware.

In order to provide the above benefits, the diamine tetracarboxylate chelant is added to give a level of material in solution of from 0.05% to 10% by weight of the composition, preferably from 0.05% to 3% and most preferably from 0.1 % to 1.5 %. This is normally achieved by incorporation of the diamine tetracarboxylate into the product composition used in the washing process, although direct addition of the diamine tetracarboxylate to the wash liquor or introduction via an additive product separate from the main wash product is also within the scope of the present invention.

Preferred EDDS compounds for inclusion in the granular detergent compositions are the free acid form and the sodium or magnesium salt thereof. Examples of such preferred sodium salts of EDDS include Mg EDDS and Mg2 EDDS.

The magnesium complexes are the most preferred for inclusion in granular compositions in accord with the invention. These complexes may be added to the compositions as such, or they may be formed during the process for making the composition by the reaction of an inert magnesium salt such as MgCl2 or Mg SO4 with an EDDS compound added as either the acid, or as a salt or complex. Where the EDDS compound is added in the making process, together with the inert magnesium salt, it is preferred that the molar ratio of magnesium to EDDS should be greater than 1:1, preferably greater than 3:1, to ensure formation of the desired magnesium complexes.

The structure of the acid form of EDDS is as follows.

EDDS can be synthesised, for example, from readily available, inexpensive starting materials such as maleic anhydride and ethylenediamine as follows.

A more complete disclosure of methods for synthesising EDDS from commercially available starting materials can be found in US Patent 3,158,635, Kezerian and Ramsay, issued November 24, 1964. The synthesis of EDDS from maleic anhydride and ethylene diamine yields a mixture of three optical isomers, [R,R], [S,S], and [S,R], due to the two asymmetric carbon atoms. The biodegradation of EDDS is optical isomer-specific, with the [S,S] isomer degrading most rapidly and extensively.

The [S,S] isomer of EDDS can be synthesised from L-aspartic acid and 1,2-dibromoethane, as follows.

A more complete disclosure of the reaction of L-aspartic acid with 1,2dibromoethane to form the [S,S] isomer of EDDS can be found in Neal and Rose, Stereospecific Ligands and Their Complexes of Ethylenediamine-discuccinic Acid, Inorganic Chemistrv, Vol. 7 (1968), pp. 2405-2412.

A further class of chelant suitable for the present invention is ethylenediamine diglutaric acid (EDDG), 2-hydroxypropylenediamine disuccinic acid (HPDDS) as disclosed in US.Patent Application No 08/026,884, which provide soil removal benefit in detergent compositions.

Optional Detergent Ingredients The detergent compositions may in addition comprise in general terms those ingredients commonly found in detergent products which may include organic surfactants, detergent builders, anti-redeposition and soil suspension agents, suds suppressors, enzymes, optical brighteners, photoactivated bleaches, perfumes, filler salts, anti-corrosion agents and colours.

Laundry detergent compositions may also comprise fabric softening and antistatic agents.

Detergent surfactants A wide range of surfactants can be used in the detergent 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-Anionic Surfactants Mixtures of anionic surfactants are suitable herein, particularly blends of sulphate, sulphonate and/or carboxylate surfactants. Mixtures of sulphonate and sulphate surfactants are normally employed in a sulphonate to sulphate weight ratio of from 5:1 to 1:2, preferably from 3:1 to 2:3, more preferably from 3:1 to 1:1. Preferred sulphonates include alkyl benzene sulphonates having from 9 to 15, especially 11 to 13 carbon atoms in the alkyl radical, and alpha-sulphonated methyl fatty acid esters in which the fatty acid is derived from a C12-C18 fatty source, preferably from a C16-C18 fatty source. In each instance the cation is an alkali metal, preferably sodium. Preferred sulphate surfactants in such sulphonate sulphate mixtures are alkyl sulphates having from 12 to 22, preferably 16 to 18 carbon atoms in the alkyl radical.

Another useful surfactant system comprises a mixture of two alkyl sulphate materials whose respective mean chain lengths differ from each other. One such system comprises a mixture of C14-C15 alkyl sulphate and C16-C18 alkyl sulphate in a weight ratio of C14-C15: C16-C18 of from 3:1 to 1:1. The alkyl sulphates may also be combined with alkyl ethoxy sulphates having from 10 to 20, preferably 10 to 16 carbon atoms in the alkyl radical and an average degree of ethoxylation of 1 to 6. The cation in each instance is again an alkali metal, preferably sodium.

Another highly preferred anionic surfactant system comprises a mixture of a C12-C20 alkyl sulphate salt with a water soluble C1l-Cl8 alkyl ethoxysulfate salt containing an average of from 1 to 7 ethoxy groups per mole wherein the weight ratio of alkyl sulphate to alkyl ethoxysulfate salt lies in the range from 2 1 to 19 1, more preferably from 3 1 to 12 1 and most preferably from 3.5 1 to 10 1.

The alkyl sulphate salts may be derived from natural or synthetic hydrocarbon sources. Preferred examples of such salts include the substantially branched C14-C15 alkyl sulphate salts, that is where the degree of branching of the C14-C15 alkyl chain is greater than about 20%. Such substantially branched C14-C15 alkyl sulphate salts are usually derived from synthetic sources. Also preferred are C 1 6-C20 alkyl sulphate salts which are usually derived from natural sources such as tallow fat and marine oils.

The C1l-Cl8 alkyl ethoxysulfate salt comprises a primary alkyl ethoxysulfate which is derived from the condensation product of a Cl 1- C 18 alcohol condensed with an average of from one to seven ethylene oxide groups per mole. Preferred are the C 12-C 15 alkyl ethoxysulfate salts with an average of from one to five ethoxy groups per mole, and most preferably with an average of from one to three ethoxy groups per mole.

The C1l-Cl8 alcohol itself can be obtained from natural or synthetic sources. Thus, Cl 1-C18 alcohols, derived from natural fats, or Ziegler olefin build-up, or OXO synthesis can form suitable sources for the alkyl group. Examples of synthetically derived materials include Dobanol 25 (RTM) sold by Shell Chemicals (UK) Ltd which is a blend of C12-C15 alcohols, Ethyl 24 sold by the Ethyl Corporation, a blend of C13-C15 alcohols in the ratio 67% C13, 33% C15 sold under the trade name Lutensol by BASF GmbH and Synperonic (RTM) by ICI Ltd., and Lial 125 sold by Liquichimica Italiana. Examples of naturally occurring materials from which the alcohols can be derived are coconut oil and palm kernel oil and the corresponding fatty acids.The level of Cl l-Cl8 alkyl ethoxysulfate is preferably from 0.5% to 10% more preferably from 0.5% to 5% and most preferably from 1 % to 3% by weight of the composition.

Other anionic surfactants suitable for the purposes of the invention are the alkali metal sarcosinates of formula R-CON (R1) CH2 COOM wherein R is a Cg-C17 linear or branched alkyl or alkenyl group, R1 is a C1-C4 alkyl group and M is an alkali metal ion. Preferred examples are the lauroyl, Cocoyl (C12-C14), myristyl and oleyl methyl sarcosinates in the form of their sodium salts.

B-Nonionic Surfactants One class of nonionic surfactants useful in the present invention comprises condensates of ethylene oxide with a hydrophobic moiety, providing surfactants having an average hydrophilic-lipophilic balance (HLB) in the range from 8 to 17, preferably from 9.5 to 13.5, more preferably from 10 to 12.5. The hydrophobic (lipophilic) moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

Especially preferred nonionic surfactants of this type are the Cg-C15 primary alcohol ethoxylates containing an average of from 3-8 moles of ethylene oxide per mole of alcohol, particularly the C14-C15 primary alcohols containing an average of from 6-8 moles of ethylene oxide per mole of alcohol and the C 12-C 15 primary alcohols containing an average of from 3-5 moles of ethylene oxide per mole of alcohol.

Another class of nonionic surfactants comprises alkyl polyglucoside compounds of general formula RO (CnH2nO)tZx wherein Z is a moiety derived from glucose; R is a saturated hydrophobic alkyl group that contains from 6 to 18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.1 to 4, the compounds including less than 10% unreacted fatty alcohol and less than 50% short chain alkyl polyglucosides. Compounds of this type and their use in detergent compositions are disclosed in EP-B 0070074, 0070077, 0075996 and 0094118.

Another preferred nonionic surfactant is a polyhydroxy fatty acid amide surfactant compound having the structural formula:

wherein: R1 is H, C1-C4 hydrocarbyl, 2-hydroxy ethyl, 2-hydroxy propyl, or a mixture thereof, preferably C1-C4 alkyl, more preferably C1 or C2 alkyl, most preferably C1 alkyl (i.e., methyl); and R2 is a Cg-C31 hydrocarbyl, preferably straight chain C7-C1g alkyl or alkenyl, more preferably straight chain Cg-C17 alkyl or alkenyl, most preferably straight chain C1l-Cl7 alkyl or alkenyl, or mixture thereof: and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxlylated derivative (preferably ethoxylated or propoxylated) thereof.Z preferably will be derived from a reducing sugar in a reductive amination reaction; more preferably Z is a glycityl. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose, and xylose. As raw materials, high dextrose corn syrup, high fructose corn syrup, and high maltose corn syrup can be utilized as well as the individual sugars listed above. These corn syrups may yield a mix of sugar components for Z. It should be understood that it is by no means intended to exclude other suitable raw materials. Z preferably will be selected from the group consisting of -CH2-(CHOH)n-CH2OH, -CH(CH2OH)-(CHOH)n 1 - CH2OH, -CH2-(CHOH)2(CHOR')(CHOH)-CH2OH, where n is an integer from 3 to 5, inclusive, and R' is H or a cyclic or aliphatic monosaccharide, and alkoxylated derivatives thereof. Most preferred are glycityls wherein n is 4, particularly -CH2-(CHOH)4-CH2OH.

In Formula (I), R1 can be, for example, N-methyl, N-ethyl, N-propyl, Nisopropyl, N-butyl, N-2-hydroxy ethyl, or N-2-hydroxy propyl.

R2-CO-N < can be, for example, cocamide, stearamide, oleamide, lauramide; myristamide, capricamide, palmitamide, tallowamide, etc.

Z can be 1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl, 1-deoxylactitl, 1-deoxygalactityl, 1-deoxymannityl, 1-deoxymalto- triotityl, etc. Preferred compound are N-methyl N-ldeoxyglucityl C14 C18 fatty acid amides.

A further class of surfactants suitable for the purposes of the invention are the gemini polyhydroxyfatty acid amide more fully disclosed in US Patent Application No 08/187251.

C-Semi-polar surfactants A further class of surfactants are the semi-polar surfactants such as amine oxides. Suitable amine oxides are selected from mono C6-C2O, preferably C10-C14 N-alkyl or alkenyl amine oxides and propylene-1 ,3- diamine dioxides wherein the remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

D-Cationic Surfactants Cationic surfactants can also be used in the detergent compositions herein and suitable quaternary ammonium surfactants are selected from mono C8-C16, preferably C10-C14 N-alkyl or alkenyl ammonium surfactants wherein remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

Laundry detergent compositions of the present invention comprise from 3 % to 30% of the present surfactant but more usually comprise from 5 % to 20%, more preferably from 7% to 15% surfactant by weight of the compositions.

Machine dishwashing detergent compositions of the present invention comprise from 0% to 10% by weight, preferably from 0.5% to 10% by weight, most preferably from 1 % to 5 % of surfactant by weight of the compositions. The surfactants may be selected from anionic, cationic, nonionic, amphotonic or zwitterionic surfactants. Most preferably the surfactants are low-foaming. A typical listing of surfactants for inclusion in automatic dishwashing detergent compositions is given in EP-A-0414 549.

Combinations of surfactant types are preferred, more especially anionicnonionic and also anionic-nonionic-cationic blends. Particularly preferred combinations are described in GB-A-2040987 and EP-A-0087914.

Although the surfactants can be incorporated into the compositions as mixtures, it is preferable to control the point of addition of each surfactant in order to optimise the physical characteristics of the composition and avoid processing problems.

Detergent Builders Another highly preferred component of the detergent compositions of the invention is a detergent builder system comprising one or more other nonphosphate detergent builders. These can include, but are not restricted to, alkali metal aluminosilicates, monomeric polycarboxylates, 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 than two carbon atoms, crystalline layered sodium silicates, borates, carbonates, bicarbonates, silicates and mixtures of any of the foregoing.

Whilst a range of aluminosilicate ion exchange materials can be used, preferred sodium aluminosilicate zeolites as disclosed in British Patent 1429143, have the unit cell formula Naz [(A102) z (SiO2 )y] xH 20 wherein z and y are at least 6; the molar ratio of z to y is from 1.0 to 0.5 and x is at least 5, preferably from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate materials are in hydrated form and are preferably crystalline, containing from 10% to 28%, more preferably from 18% to 22% water in bound form.

Aluminosilicate ion exchange materials useful in the practice of this invention are commercially available and can be naturally occurring materials, but are preferably synthetically derived. A method for producing aluminosilicate ion exchange materials is discussed in US Patent No. 3,985,669. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite B, Zeolite P, Zeolite X, Zeolite HS, Zeolite MAP and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material is Zeolite A and has the formula Na 12 [(A1O2) 12 (so02)12 ]. xH2O wherein x is from 20 to 30, especially 27.Zeolite X of formula Na86 [(A1O2)86(Sio2)lO6]- 276 H2O is also suitable, as well as Zeolite HS of formula Na6 [(A1O2)6(SiO2)6] 7.5 H2 O).

Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic acidity/constant (pK1) of less than 9, preferably of between 2 and 8.5, more preferably of between 4 and 7.5.

The carboxylate or polycarboxylate builder, as disclosed in WO 94/03554, can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance.

Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates.

Suitable carboxylates containing one carboxy group include the water soluble salts of lactic acid, glycolic acid and ether derivatives thereof as disclosed in Belgian Patent Nos. 831,368, 821,369 and 821,370.

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 fumaric acid, as well as the ether carboxylates described in German Offenlegenschrift 2,446,686, and 2,446,687 and U.S. Patent No. 3,935,257 and the sulfinyl carboxylates described in Belgian Patent No. 840,623. 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 Patent No.7205873-A, 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 cyclopentanecis,cis,cis-tetracarboxylates, cyclopentadienide pentacarboxylates, 2,3,4,5-tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5tetrahydrofuran - 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 components of builder systems of detergent compositions in accordance with the present invention.

Other suitable water soluble organic salts are the 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 MWt 20005000 and their copolymers with maleic anhydride, such copolymers having a molecular weight of from 20,000 to 70,000, especially about 40,000. These materials are normally used at levels of from 0.5% to 10% by weight more preferably from 0.75% to 8%, most preferably from 1% to 6% by weight of the composition.

Preferred non-phosphate builder salts are the crystalline layered sodium silicates of the general formula NaMSix02x+ 1 .yH20 wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20. Crystalline layered sodium silicates of this type are disclosed in EP-A-0164514 and in the U.K. Patent Application No 9,216,409.4, and methods for their preparation are disclosed in DE-A3417649 and DE-A-3742043.

The incorporation of other ingredients additional to the crystalline layered silicate and ionisable water soluble compound can be advantageous particularly in the processing of the particulate and also in enhancing the stability of detergent compositions in which the particulates are included.

In particular, certain types of agglomerates may require the addition of one or more binder agents in order to assist in binding the silicate and ionisable water soluble material so as to produce particulates with acceptable physical characteristics. The binder agents may be present at a level of from 0% to 20% by weight of the composition. Preferably, the binder agents will be in intimate admixture with the silicate and ionisable water soluble material. Preferred binder agents have a melting point between 30"C-70"C. The binder agents are preferably present in amounts from 1-10% by weight of the composition and most preferably from 2-5 % by weight of the composition.

Preferred binder agents include the C10-C'20 alcohol ethoxylates containing-from 5-100 moles of ethylene oxide per mole of alcohol and more preferably the C15-C20 primary alcohol ethoxylates containing from 20-100 moles of ethylene oxide per mole of alcohol.

Other preferred binder agents include certain polymeric materials.

Polyvinylpyrrolidones with an average molecular weight of from 12,000 to 700,000 and polyethylene glycols with an average weight of from 600 to 10,000 are examples of such polymeric materials. Copolymers of maleic anhydride with ethylene, methylvinyl ether or methacrylic acid, the maleic anhydride constituting at least 20 mole percent of the polymer are further examples of polymeric materials useful as binder agents. These polymeric materials may be used as such or in combination with solvents such as water, propylene glycol and the above mentioned C10-C20 alcohol ethoxylates containing from 5-100 moles of ethylene oxide per mole. Further examples of binder agents in accord with the invention include the C10 -C20 monoand diglycerol ethers and also the C10-C20 fatty acids.Solutions of certain inorganic salts including sodium silicate are also of use for this purpose.

Cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose, and homo- or co-polymeric polycarboxylic acid or their salts are other examples of binder agents in accord with the invention.

The particulates can take a variety of physical forms such as extrudates, marumes, agglomerates, flakes or compacted granules. A preferred process for preparing compacted granules comprising crystalline layered silicate and a solid, water-soluble ionisable material has been disclosed in the commonly assigned EP-581895.

The detergent compositions useful in carrying out the present invention, will comprise non-phosphate detergent builder compounds at a level of from 1 % to 80% by weight of the compositions, more preferably from 10% to 60% by weight and most preferably from 20% to 50% by weight.

Within the preferred detergent compositions, sodium aluminosilicate such as Zeolite A will comprise from 20% to 80% by weight of the total amount of builder, a monomeric or oligomeric carboxylate will comprise from 5 % to 30% by weight of the total amount of builder and the crystalline layered silicate will comprise from 10% to 65% by weight of the total amount of builder. In such compositions the builder system preferably also incorporates a combination of auxiliary inorganic and organic builders such as sodium carbonate and maleic anhydride/acrylic acid copolymers in amounts of up to 35 % by weight of the total builder.

Detergent bleaches The solid detergent compositions of the present invention will generally include an inorganic perhydrate bleach, normally in the form of the sodium salt. The perhydrate is usually incorporated at a level of from 3 % to 40% by weight, more preferably from 5% to 30% by weight and most preferably from 5% to 15% by weight of the composition.

The perhydrate may be any of the inorganic salts such as perborate, percarbonate, perphosphate and persilicate salts but is conventionally an alkali metal normally sodium, perborate or percarbonate. Sodium perborate can be in the form of the monohydrate of nominal formula NaBO2H202 or the tetrahydrate NaBO2H202.3H2O.

Sodium percarbonate, which is the preferred perhydrate, is an addition compound having a formula corresponding to 2Na2CO3 .3H2O2, and is available commercially as a crystalline solid. Although the percarbonate can be incorporated into detergent compositions without additional protection, preferred executions of such compositions utilise a coated form of the material. The most preferred coating material comprises a mixture of alkali metal sulphate and carbonate salts. 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. Preferably, the mixed salt is of sodium sulphate and sodium carbonate which has the general formula Na2SO4.n.Na2CO3 wherein n is form 0.1 to 3, preferably n is from 0.3 to 1.0 and most preferably n is from 0.2 to 0.5.

Another suitable coating material is sodium silicate of SiO2:Na2O ratio from 1.6:1 to 3.4:1, preferably 2.8:1, applied as an aqueous solution to give a level of from 2% to 10%, (normally from 3% to 5%) of silicate solids by weight of the percarbonate. Boro silicate (described in U.S Patent 4,526,698) or magnesium silicate can also be included in the coating.

Bleach systems incorporated into detergent compositions of the present invention preferably include solid peroxyacid bleach precursors (bleach activators). The solid peroxyacid bleach precursors are normally incorporated at a level of from 1 % to 20%, more preferably from 1 % to 15%, most preferably from 1% to 10% by weight of the composition.

These precursors probably contain one or more N- or 0- acyl groups, which precursors can be selected from a wide range of classes. Suitable classes include anhydrides, esters, imides and acylated derivatives of imidazoles and oximes, and examples of useful materials within these classes are disclosed in GB-A-1586789. The most preferred classes are esters such as are disclosed in GB-A-836988, 864,798, 1147871 and 2143231 and imides such as are disclosed in GB-A-855735 & 1246338.

Particularly preferred precursor compounds are the N,N,N1N1 tetra acetylated compounds of formula

wherein x can be O or an integer between 1 & 6.

Examples include tetra acetyl methylene diamine (TAMD) in which x =1, tetra acetyl ethylene diamine (TAED) in which x=2 and tetraacetyl hexylene diamine (TAHD) in which x=6. These and analogous compounds are described in GB-A-907356. The most preferred peroxyacid bleach precursor is TAED.

Another preferred class of peroxyacid bleach activator compounds are the amide substituted compounds of the following general formulae:

wherein R1 is an aryl or alkaryl group with from about 1 to about 14 carbon atoms, R2 is an alkylene, arylene, and alkarylene group containing from about 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 about 6 to 12 carbon atoms.

R2 preferably contains from about 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 total. Amide substituted bleach activator compounds of this type are described in EP-A-0170386.

Other peroxyacid bleach precursor compounds include Nonanoyl Oxy Benzene Sulphonate (NOBS, described in US 4,412,934), 3,5,trimethylhexanoyl Oxy Benzene Sulphonate ( ISONOBS, described in EP 120,591 ), acetoxy benzene sulfonate, benzoyloxy benzene sulfonate as disclosed in, for example, EP-A-0341947, Benzoyl caprolactam and Phenol sulphonate ester of acylamido caproic acid.

The compositions of the invention may also contain organic peroxyacids at a level of from 1 5to to 15 % by weight, more preferably from 1 % to 10% by weight of the composition . A particularly preferred class are the amide substituted peroxyacids of general formulae:

where R1, R2 and R5 are as defined previously for the corresponding amide substituted peroxyacid bleach activator compounds.

Other organic peroxyacids include diperoxy dodecanedioc acid, diperoxy tetra decanedioc acid, diperoxyhexadecanedioc acid, mono- and diperazelaic acid, mono- and diperbrassylic acid, monoperoxy phthalic acid, perbenzoic acid, and their salts as disclosed in, for example, EP-A0341 947.

Optional Chelant Ingredients The detergent compositions may contain optional chelant ingredients.

Such optional chelants may include the organic phosphonates, including amino alkylene poly (alkylene phosphonate), alkali metal ethane 1hydroxy diphosphonates, nitrilo trimethylene phosphonates, ethylene diamine tetra methylene phosphonates and. diethylene triamine penta methylene phosphonates. The phosphonate compounds may be present either in their acid form or as a complex of either an alkali or alkaline metal ion, the molar ratio of said metal ion to said phosphonate compound being at least 1:1. Such complexes are described in US-A-4,259,200.

Preferably, the organic phosphonate compounds where present are in the form of their magnesium salt, but in the instance of HEDP it will preferably be in its acid form. The level of phosphorus containing chelants in the compositions of the invention lie in the range from 0% to 20%, preferably from 0% to 10%, more preferably from 0% to 6% by weight of the composition.

Silicates are useful components of automatic dishwashing detergent compositions and laundry detergent compositions. Suitable silicates include the water soluble sodium silicates with an SiO2 : Na2O ratio of from 1.0 to 3.2. The silicates may be in the form of either the anhydrous salt or a hydrated salt. Sodium silicate with an SiO2 : Na2O ratio of 2.0 is most preferred. Silicates are present in the machine dishwashing detergent compositions at a level of from 5% to 40% by weight of the composition, more preferably from 10% to 25% by weight of the compositidn.

Whilst soluble silicates serve a variety of purposes in conventional laundry detergent formulations, their presence may be unnecessary in detergent compositions incorporating crystalline layered silicate material.

However as the crystalline layered silicate, which forms part of the builder system of a detergent composition, must be added as a dry mix ingredient, soluble silicates may still be useful as structurants in the spray dried granules that normally form part of a laundry detergent composition. This is particularly desirable if the spray dried granule does not incorporate an aluminosilicate builder and would otherwise comprise only organic materials. Suitable silicates are those having an SiO2:Na2O ratio in the range from 1.6 to 3.4, ratios from 2.0 to 2.8 being preferred.

Silicates are present in the laundry machine granule detergent compositions at a level of from 1 % to 20% by weight of the composition, preferably from 1 % to 10% by weight, more preferably from 1 % to 5% by weight of the composition.

Detergent compositions in which solid peroxybleach precursors are protected via an acid coating to minimise fabric colour damage are disclosed in EP-A-571524.

Anti-redeposition and soil-suspension agents suitable herein include cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose, homo-or co-polymeric polycarboxylic acids or their salts and ployamino compounds. Polymers of this type include the polyacrylates and copolymers of maleic anhydride with ethylene, methylvinyl ether or methacrylic acid, the maleic anhydride constituting at least 20 mole percent of the copolymer disclosed in detail in EP-A137669. Polyamino compounds such as those derived from aspartic acid are disclosed in EP-A-305282, EP-A-305283 and EP-A-351629. These materials are normally used at levels of from 0.5% to 10% by weight, more preferably from 0.75% to 8%, most preferably from 1% to 6% by weight of the composition.

Other useful polymeric materials are the polyethylene glycols, particularly those of molecular weight 1000-10000, more particularly 2000 to 8000 and most preferably about 4000. These are used at levels of from 0.20% to 5% more preferably from 0.25 % to 2.5 % by weight. These polymers and the previously mentioned homo- or co-polymeric polycarboxylate salts are valuable for improving whiteness maintenance, fabric ash deposition, and cleaning performance on clay, proteinaceous and oxidizable soils in the presence of transition metal impurities.

Preferred optical brighteners are anionic in character, examples of which are disodium 4,41 -bis-(2-diethanolamino-4-anilino -s- triazin-6ylamino)stilbene-2:21 disulphonate, disodium 4,41 -bis-(2-morpholino -4 anilino-2-triazin-6-ylaminostilbene-2 :21 -disulphonate , disodium 4, 41-bis (2 ,4-dianilino-s-triazin-6-ylamino)stilbene-2 ::21 - disulphonate, monosodium 41,41 1-bis-(2 ,4-dianilino-s-triazin-6-ylamino)stilbene-2- sulphonate, disodium 4,41 -bis-(2-anilino-4-(N-methyl-N-2- hydroxyethylamino)-2-triazin-6-ylamino)stilbene-2 , 21 - disulphonate, disodium 4 ,41-bis-(4-phenyl-2, 1 ,3-triazol-2-yl)stilbene-2 ,2 1 disulphonate, disodium 4,4 1bis(2-anilino-4-( 1 -methyl-2-hydroxyethylamino)-s-triazin-6- ylamino)stilbene-2,2 1disulphonate and sodium 2(stilbyl-411 -(naphtho- 11,2l::4,5)-1,2,3 - triazole-211- sulphonate, disodium 4,4' -bis-(2- sulphostyryl)-biphenyl. These are used at levels of from 0.05% to 1.2% by weight of the composition.

Soil-release agents useful in detergent compositions are conventionally copolymers or terpolymers of terephthalic acid with ethylene glycol and/or propylene glycol units in various arrangements. Examples of such polymers are disclosed in the commonly assigned US Patent Nos.

4116885 and 4711730 and European Published Patent Application No.

0272033. A particular preferred polymer has the formula

Certain polymeric materials such as polyvinyl pyrrolidones, typically of MWt 5000-20000, preferably 10000-15000, also form useful agents in preventing the transfer of labile dyestuffs between fabrics during the washing process.

Soil-release agents are present in the detergent composition at a level of from 0.01 % to 10% by weight of the composition,preferably from 0.1 % to 5% by weight of the composition, more preferably from 0.2% to 3% by weight of the composition.

Another optional detergent composition ingredient is a suds suppressor, exemplified by silicones, and silica-silicone mixtures. Silicones can be generally represented by alkylated polysiloxane materials while silica is normally used in finely divided forms, exemplified by silica aerogels and xerogels and hydrophobic silicas of various types. These materials can be incorporated as particulates in which the suds suppressor is advantageously releasably incorporated in a water-soluble or waterdispersible, substantially non-surface-active detergent-impermeable carrier. Alternatively the suds suppressor can be dissolved or dispersed in a liquid carrier and applied by spraying on to one or more of the other components.

As mentioned above, useful silicone suds controlling agents can comprise a mixture of an alkylated siloxane, of the type referred to hereinbefore, and solid silica. Such mixtures are prepared by affixing the silicone to the surface of the solid silica. A preferred silicone suds controlling agent is represented by a hydrophobic silanated (most preferably trimethylsilanated) silica having a particle size in the range from 10 nanometers to 20 nanometers and a specific surface area above 50 m2/g, intimately admixed with dimethyl silicone fluid having a molecular weight in the range from about 500 to about 200,000 at a weight ratio of silicone to silanated silica of from about 1:1 to about 1:2.

A preferred silicone suds controlling agent is disclosed in Bartollota et al.

US Patent 3,933,672. Other particularly useful suds suppressors are the self-emulsifying silicone suds suppressors, described in German Patent DTOS 2,646,126. An example of such a compound is DC0544, commercially available from Dow Corning, which is a siloxane/glycol copolymer.

A highly preferred particulate suds controlling agent is described in EP A-0210731 and comprises a silicone antifoam compound and an organic carrier material having a melting point in the range 50"C to 85"C, wherein the organic carrier material comprises a monoester of glycerol and a fatty acid having a carbon chain containing from 12 to 20 carbon atoms. EP-A-0210721 discloses other preferred particulate suds controlling agent s wherein the organic carrier material is a fatty acid or alcohol having a carbon chain containing from 12 to 20 carbon atoms, or a mixture thereof, with a melting point of from 45"C to 800C.

Other highly preferred particulate suds controlling agents are described in copending European Application 91870007.1 in the name of the Procter and Gamble Company which agents comprise silicone antifoam compound, a carrier material, an organic coating material and glycerol at a weight ratio of glycerol : silicone antifoam compound of 1:2 to 3:1.

Copending European Application 91201342.0 also discloses highly preferred particulate suds controlling agents comprising silicone antifoam compound, a carrier material, an organic coating material and crystalline or amorphous aluminosilicate at a weight ratio of aluminosilicate silicone antifoam compound of 1:3 to 3:1. The preferred carrier material in both of the above described highly preferred granular suds controlling agents is starch.

An exemplary particulate suds controlling agent for use herein is a particulate agglomerate component, made by an agglomeration process, comprising in combination (i) from 5% to 30%, preferably from 8% to 15% by weight of the component of silicone antifoam compound, preferably comprising in combination polydimethyl siloxane and silica; (ii) from 50% to 90%, preferably from 60% to 80% by weight of the component, of carrier material, preferably starch; (iii) from 5% to 30two, preferably from 10% to 20% by weight of the component of agglomerate binder compound, where herein such compound can be any compound, or mixtures thereof typically employed as binders for agglomerates, most preferably said agglomerate binder compound comprises a C16-Cl8 ethoxylated alcohol with a degree of ethoxylation of from 50 to 100; and (iv) from 2% to 15%, preferably from 3% to 10%, by weight of C12 C22 hydrogenated fatty acid.

The suds suppressors described above are normally employed at levels of from 0.01 % to 15 % by weight of the composition, preferably from 0.05 % to 10% by weight, more preferably from 0.15to to 5 % by weight of the composition.

Another optional ingredient useful in the present invention is one or more enzymes.

Preferred enzymatic materials include the commercially available amylases, neutral and alkaline proteases, lipases, esterases and cellulases 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 and Savinase by Novo Industries A/S (Denmark) and Maxatase by International Bio-Synthetics, Inc. (The Netherlands).

Preferred amylases include, for example, a-amylases obtained from a special strain of B licheniforms, described in more detail in GB-1 ,269,839 (Novo). Preferred commercially available amylases include for example, Rapidase, sold by International Bio-Synthetics Inc, and Termamyl, sold by Novo Industries A/S.

An especially preferred lipase enzyme is manufactured and sold by Novo Industries A/S (Denmark) under the trade name Lipolase (Biotechnology Newswatch, 7 March 1988, page 6) and mentioned along with other suitable lipases in EP-A-0258068 (Novo).

Fabric softening agents can also be incorporated into detergent compositions in accordance with the present invention. These agents may be inorganic or organic in type. Inorganic softening agents are exemplified by the smectite clays disclosed in GB-A-1,400,898. Organic fabric softening agents include the water insoluble tertiary amines as disclosed in GB-A-1514276 and EP-B-0011340.

Their combination with mono C12-Cl4 quaternary ammonium salts is disclosed in EP-B-0026527 & 528. Other-useful organic fabric softening agents are the dilong chain amides as disclosed in EP-B-0242919.

Additional organic ingredients of fabric softening systems include high molecular weight polyethylene oxide materials as disclosed in EP-A0299575 and 0313146.

Levels of smectite clay are normally in the range from 5 % to 15 %, more preferably from 8% to 12% by weight, with the material being added as a dry mixed component to the remainder of the formulation. Organic fabric softening agents such as the water-insoluble tertiary amines or dilong chain amide materials are incorporated at levels of from 0.5% to 5 % by weight, normally from 1 % to 3 % by weight, whilst the high molecular weight polyethylene oxide materials and the water soluble cationic materials are added at levels of from 0.1 % to 2%, normally from 0.15 % to 1.5 % by weight.Where a portion of the composition is spray dried, these materials can be added to the aqueous slurry fed to the spray drying tower, although in some instances it may be more convenient to add them as a dry mixed particulate, or spray them.as a molten liquid on to other solid components of the composition.

Detergent Formulation Laundry detergent compositions useful in carrying out the present invention can be in paste, liquid or granular forms.

In heavy duty liquid compositions, phosphonates such as diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts provide the key contribution to the removal of beverage stains including Tea, Coffee, Wine and Blackberry. However these heavy duty liquid compositions tend to cause enamel loss and thus require enamel corrosion inhibitors which are either expensive (eg silanes) or are difficult to stabilise and formulate at low/medium (6-9.5) pH range (eg silicates).

The partial or total replacement of phosphonates by EDDS improves the enamel compatibility of the formulation and permits the use of a lower level of silanes ( < 0.5%) or silicate (0%-3%).

Thus, the present invention relates to a detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 0.5% of silane corrosion inhibitors by weight of the composition.

Also, the present invention relates to a detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1 -hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 3 % of silicate corrosion inhibitors by weight of the composition.

In general granular detergent compositions can be made via a variety of methods including dry mixing, spray drying, agglomeration and granulation and preferred methods involve combinations of these techniques.

The bulk density of the granular detergent compositions of the present invention may be in the range of about 450 to 600 g/litre as is typical for conventional laundry detergent compositions. Alternatively, the granular detergent compositions may be concentrated granular detergent compositions that are characterised by a relatively high density in comparison with conventional detergent compositions. Such high density compositions have a bulk density of at least 650 g/litre, more usually at least 700 g/litre and more preferably from 800 g/litre to 1100 g/litre.

Concentrated laundry detergent compositions also normally incorporate at least one multi-ingredient component i.e. they do not comprise compositions formed merely by dry-mixiiig individual ingredients.

Compositions in which each individual ingredient is dry-mixed are generally dusty, slow to dissolve and also tend to cake and develop poor particle flow characteristics in storage.

In heavy duty granules composition formulated with a Zeolite based spray dried granule or a Zeolite based agglomerate, the addition of silicate is necessary to provide enamel compatibility. The joint addition of silicate and zeolite in a spray dried granule or agglomerated granule causes formation of insolubles which cause residues on fabrics during the wash.

The replacement of phosphonates by EDDS provides the new effect of reducing enamel loss and corrosion, which therefore allows the use of smaller amounts of silicate ie a ratio of silicate : zeolite below 1:2 Thus, the present invention relates to a detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and zeolite spray dried granule or zeolite agglomerate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0. 15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate at a level of less than 4% by weight of the composition, wherein the weight ratio of said silicate to said zeolite spray dried granule or zeolite agglomerate granule is less than 1:2.

In heavy duty granules compositions formulated with dry mixed amorphous silicate, the high levels of silicate necessary for enamel protection cause dispensing issues due to product gelling. The replacement of phosphonate with EDDS would allow a reduction in the level of dry added silicate, thus improving product dispensing, providing enamel protection, and giving equal stain removal performance.

Thus, the present invention relates to a detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and dry mixed amorphous silicate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15 % by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate in a dry added material at a level of less than 4% by weight of the composition.

For spray dried powders, the bulk density of the particles from the spray drying tower is conventionally in the range from 540 to 600 g/litre and this is then enhanced by further processing steps such as size reduction in a high speed cutter/mixer followed by compaction. Alternatively, processes other than spray drying may be used to form a high density particulate directly.

In preferred concentrated detergent products incorporating an alkali metal percarbonate as the perhydrate salt it has been found necessary to control several aspects of the product such as its heavy metal ion content and its equilibrium relative humidity. Sodium percarbonate-containing compositions of this type having enhanced stability are disclosed in the commonly assigned PCT US 91/07205.

In ADW products, the detergent compositions useful in carrying out the present invention comprises: a)-from 0% to 0.3% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts, preferably ethane 1-hydroxy diphosphonic acid and their alkali metal or alkaline earth metal salts; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25 % of sodium silicate by weight of the composition.

The present invention relates, also, to a detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a liquid automatic dishwashing composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 5% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts, preferably ethane 1-hydroxy diphosphonic acid and their alkali metal or alkaline earth metal salts; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylene diamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25 % of sodium silicate by weight of the composition.

The invention is illustrated in the following non limiting Examples, in which all percentages are on a weight basis unless otherwise stated.

In the detergent compositions, the abbreviated component identifications have the following meanings: LAS : Sodium linear C12 alkyl benzene sulphonate TAS : Sodium tallow alkyl sulphate TAEn : Tallow alcohol ethoxylated with n moles of ethylene oxide per mole of alcohol 45EY : A C14-15 predominantly linear primary alcohol condensed with an average of Y moles of ethylene oxide Zeolite A : Hydrated Sodium Aluminosilicate of formula Nai2(AlO2SiO2)i2. 27H20 having a primary particle size in the range from 1 to 10 micrometers Citrate : Tri-sodium citrate dihydrate MA/AA :Maleic Acid/Acrylic Acid copolymer,sodium salt sold by BASF under the trade name Sokalan (g) CP 5 with a molecular weight of 90,000.

Carbonate : Anhydrous sodium carbonate PB1 : Anhydrous sodium perborate monohydrate bleach, empirical formula NaBO2.H202 PB4 : Anhydrous sodium perborate tetrahydrate TAED : Tetraacetyl ethylene diamine Phosphonate : Diethylene triamine penta (methylene phosphonic) acid (DETPMP) EDDS . Ethylenediamine-N,N'-disuccinic acid (S,S isomer) CMC : Sodium carboxymethyl cellulose Photoactivated : Tetra sulphonated Zinc Bleach Phthalocyanine Lipase : Lipolytic enzyme sold by Novo Industries A/S under the tradename Lipolase.

Protease : Proteolytic enzyme sold by Novo Industries A/S under the tradename Savinase.

Amylase : Amylolytic enzyme sold by Novo Industries A/S under the tradename Termamyl Silicate : Amorphous Sodium Silicate (SiO2:Na2O ratio normally follows) Sulphate : Anhydrous magnesium sulphate.

Silicone : Silicone antifoam STPP : Sodium tripolyphosphate (Na5P3Oi0) Example 1 i)-detergent formulation The following heavy duty granule compositions with dry mixed amorphous silicate were prepared (parts by weight). A wash process employing Product A constitutes prior art practice where Product B is an embodiment of the invention.

Ingredients A B LAS 7.0 7.0 TAS 2.4 2.4 TAE11 1.1 1.1 45E7 4.0 4.0 Zeolite A 20.5 20.5 Citrate 7.5 7.5 MA/AA 4.0 4.0 Carbonate 15.0 15.0 PB1 16.0 16.0- TAED 5.0 5.0 Phosphonate 0.38 EDDS - 0.22 CMC 0.3 0.3 Photoactivated Bleach 0.02 0.02 Savinase 1.4 1.4 Lipolase 0.4 0.4 Silicate 3.5 3.5 MgSO4 0.4 0.4 Silicone 0.4 0.4 Perfumes 0.4 0.4 Water minors and miscellaneous to balance ii)Enamel Testing The enamel loss results of the two Compositions were compared at the 40, 60, 100 cycle washing machine tests.

Procedure for enamel coupons 1-The enamel coupons are carefully halved, washed in a detergent solution, using manual operation to remove the grease, rinsed thoroughly in water and given a final rinse in IMS prior to careful drying.

2-The coupons are placed in a dessicator to dry overnight and then each is weighed, wrapped in tissue marked with an identification number and replaced in the dessicator until the weight remains stable.

3-When coupons are ready to use, each of the coupon numbers is matched with an identifying mark on the plastic cage and each coupon is secured inside the cage using a plastic wire tag.

Procedure for machine work 1-A minimum of 60 wash cycles is required, with takeoffs after each 20 cycles as explained below.

2-The clean white loads (6 lb) are put into each of the machines and the 3 cages containing the prepared coupons are added to each machine. The machines follow a temperature rotation of 40"C, 60"C, 40"C and 90"C.

The products are also rotated between machines.

3-Each extended time interval between wash cycle (for example overnight) the coupons are removed, each is wrapped in its identification tissue and allowed to dry.

4-After 20 wash cycles have been completed, the coupons are removed from the cage and immersed for 2 minutes in a 0.02N EDTA solution previously heated to 80"C, then rinsed under cold running water, followed by a rinse with IMS, and dried overnight in a dessicator.

5-Each coupon is weighed until its weight remains stable and is also inspected for loss of gloss.

6- The steps 2 to 5 are repeated for as many cycles as are required.

The results are recorded as weight loss in mg/cm2 at each 20 wash cycle takeoff.

Wash Cycles A B % reduction of enamel loss (B/A) 40 2.3 1.6 30.43 60 3.2 2.1 34.37 100 3.5 2.7 22.86 Conclusion: The reduction of the level of enamel loss in machines having enamel surfaces exposed to the detergent liquor is achieved by the presence of EDDS in detergent composition.

Example 2 The following machine dishwashing detergent compositions were prepared (parts by weight). A wash process employing Product A is a prior art practice where Products B and C are embodiments of the invention.

A B C Citrate 29.0 20.0 STPP - - 25.0 MA/AA 3.7 6.0 Silicate (2 ratio) 25.5 15.0 7.5 Metasilicate - - 2.5 Carbonate - 20.0 30.0 PB1 1.9 1.9 0.98 PB4 8.6 8.6 4.3 TAED 3.8 3.8 2.4 Phosphonate 0.13 EDDS - 0.10 0.05 Savinase 4.0 4.0 2.0 Termamyl 1.5 1.0 0.7 Nonionic 1.5 1.5 0.7 surfactant Sulphate/Moisture/Miscellaneous to balance

Claims (2)

1. CLAIMS 1-The use of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylenediamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, in a detergent composition for reducing enamel loss and corrosion during a washing machine process in which siliceous surfaces of the machine or of articles washed therein are exposed to the detergent liquor.

   2-The use of diamine tetracarboxylate chelants in a detergent composition according to claim 1 wherein said diamine tetracarboxylate chelants are selected from their racemate structure and isomeric structures.

   3-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15 % by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than
2. 2.0; c)-less than 0.5% of silane corrosion inhibitors by weight of the composition.

   4-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0. 15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 3 % of silicate corrosion inhibitors by weight of the composition.

   5-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and zeolite spray dried granule or zeolite agglomerate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1 -hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0. 15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate at a level of less than 4% by weight of the composition, wherein the weight ratio of said silicate to said zeolite spray dried granule or zeolite agglomerate granule is less than 1:2.

   6-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and dry mixed amorphous silicate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1 -hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 15% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate in a dry added material at a level of less than 4% by weight of the composition.

   7-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a granular automatic dishwashing composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.3% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts, preferably ethane 1-hydroxy diphosphonic acid and their alkali metal or alkaline earth metal salts; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25 % of sodium silicate by weight of the composition.

   8-A detergent composition adapted to reduce enamel loss and corrosion wherein said detergent composition is a liquid automatic dishwashing composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 5 % of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts, preferably ethane 1-hydroxy diphosphonic acid and their alkali metal or alkaline earth metal salts;; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid, ethylenediamine diglutaric acid or 2-hydroxypropylenediamine disuccinic acid or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25 % of sodium silicate by weight of the composition.

   9-A detergent composition adapted to reduce enamel loss and corrosion according to any one of Claim 2-8 wherein said diamine tetracarboxylate chelants are selected from their racemate structure and isomeric structures.

   Amendments to the claims have been filed as follows 1-A method of reducing enamel loss and corrosion during a washing machine process in which siliceous surfaces of the machine or of articles washed therein are exposed to the detergent liquor of a detergent composition comprising diamine tetracarboxylate chelants selected from ethylenediamine disuccinic acid (EDDS), ethylenediamine diglutaric acid (EDDG) or 2-hydroxypropylenediamine disuccinic acid (HPDDS) or alkali metal, alkaline earth, ammonium or substituted ammonium salts thereof, or mixtures thereof.

   2-A method according to claim 1 wherein said diamine tetracarboxylate chelants are selected from their racemate structure and isomeric structures.

   3-A method according to either one of Claim 1 or 2, wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15% by weight of the composition of said diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 0.5% of silane corrosion inhibitors by weight of the composition.

   4-A method according to either one of Claim 1 or 2, wherein said detergent composition is a heavy duty liquid composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane l-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15% by weight of the composition of said diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 3% of silicate corrosion inhibitors by weight of the composition.

   5-A method according to either one of Claim 1 or 2, wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and zeolite spray dried granule or zeolite agglomerate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; bfi at least 0.15% by weight of the composition of said diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate at a level of less than 4% by weight of the composition, wherein the weight ratio of said silicate to said zeolite spray dried granule or zeolite agglomerate granule is less than 1:2.

   6-A method according to either one of Claim 1 or 2, wherein said detergent composition is a heavy duty granule formulated with conventional detersive surfactants, optional builders, detersive adjuncts and dry mixed amorphous silicate comprising: a)-from 0% to 0.6% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts; b)- at least 0.15% by weight of the composition of diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-amorphous silicate in a dry added material at a level of less than 4% by weight of the composition.

   7-A method according to either one of Claim 1 or 2, wherein said detergent composition is a granular automatic dishwashing composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 0.3% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acidHEDP) and their alkali metal or alkaline earth metal salts, preferably ethane i-hydroxy1diphosphonic acid and their alkali metal or alkaline earth metal salts; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25% of sodium silicate by weight of the composition.

   8-A method according to either one of Claim 1 or 2, wherein said detergent composition is a liquid automatic dishwashing composition formulated with conventional detersive surfactants, optional builders and detersive adjuncts comprising: a)-from 0% to 5% of phosphonate chelants selected from diethylene triamine penta (methylene phosphonic) acid (DTPMP), diethylene diamine tetra (methylene phosphonic) acid (DDTMP), ethane 1-hydroxy diphosphonic acid (HEDP) and their alkali metal or alkaline earth metal salts, preferably ethane 1-hydroxy diphosphonic acid and their alkali metal or alkaline earth metal salts; b)- at least 0.09% by weight of the composition of diamine tetracarboxylate chelants, wherein the weight ratio of said phosphonate to said diamine tetracarboxylate has a value of less than 2.0; c)-less than 25% of sodium silicate by weight of the composition.