EP1529834A1

EP1529834A1 - Detergent particles

Info

Publication number: EP1529834A1
Application number: EP04256806A
Authority: EP
Inventors: Stuart Andrew Caldwell; Nicholas Alexander Turnbull
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 2003-11-10
Filing date: 2004-11-04
Publication date: 2005-05-11

Abstract

The present invention relates to a method for making a laundry detergent particle comprising from 10 to 60 wt % (anhydrous basis) zeolite, from 12 to 75 wt % polycarboxylate polymer, and optional additional ingredients to 100 % by weight, said method comprising preparing an aqueous slurry comprising zeolite, and polycarboxylate polymer and optional additional ingredients and spray drying the slurry. The weight ratio of zeolite (anhydrous basis) to polycarboxylate polymer in the slurry is from 4:1 to 1:2. The particles have been found to reduce caking of detergent product whilst providing improved cleaning compared with the addition of the polycarboxylate polymer as a separate granule. The invention also includes detergent compositions comprising such particles. The particles may be incorporated into a finished detergent composition as part of an agglomerate or extrudate.

Description

Technical field

The present invention relates to the field of laundry detergent compositions and in particular to methods for making particles which comprise polymer and which are suitable for use in laundry detergent compositions.

Background of the Invention and Prior Art

It is often desirable to incorporate polycarboxylate polymers into detergent compositions as part of an effective builder system. They are available from suppliers as powder, in solution or in granular form. EP-A-421664 states that these types of polymers are generally added to detergent formulations either in the form of a dried powder that is formed by spray-drying a solution, dispersion, slurry or emulsion of polymer in a liquid ("wet polymer"), or directly as wet polymer to a detergent formulation in slurry form before drying. It is then stated that in both cases the product has a number of undesirable characteristics: the powder formed by spray drying wet polymer is said to be hygroscopic and therefore tends to become sticky upon storage or in the final formulation. EP-A-421664 solves the problem by providing an agglomerate made by agglomerating a dry polymer and an inorganic component.
It is well known to incorporate these polymers into spray dried detergent base granules. They are usually incorporated at low levels. DE-A-3316513 describes use of wet polymer to prepare a zeolite particle. The problem addressed is that of effectively dispersing zeolite in aqueous wash liquor in view of the water insoluble, finely particulate nature of zeolite. The particles disclosed contain 70 to 95 wt% zeolite and 5 to 30 wt% polycarboxylic acid polymer. Polycarboxylate polymer is also incorporated into spray-dried granules in EP-A-640 684 for making phosphate-free automatic dishwashing compositions; WO92/13937 for making a granular additive for pre-treating hard water or as an additive for a cleaning composition with polymer at very high levels; EP-A-270 240 for making low particle porosity spray-dried powders; and in EP-A-137 669 for preparing detergent compositions that are phosphate-free but comprise a bleach system having good bleach stability and fabric damage characteristics.
Trade literature from suppliers of these polycarboxylate polymers and patent publications such as EP-A-658189 and EP-A-759463 teach that the suppliers' granules consisting of these polymers (generally containing at least 90 wt % polymer) give the best building benefits, more specifically anti-incrustation benefits.
However, the present inventors have found that polycarboxylate polymers incorporated into detergent formulations in the form of such polymer granules still result in caking of the detergent compositions. In addition, agglomeration of the dry powder polymer is expensive. It is therefore an object of the present invention to provide a polycarboxylate polymer in particulate form for addition to detergent compositions in a cost-effective manner whilst overcoming the caking problems associated with these materials and without losing their anti-incrustation benefits.

Definition of the Invention

In accordance with the present invention there is provided a method for making a laundry detergent particle comprising from 10 to 60 wt % (anhydrous basis) zeolite, from 12 to 75 wt % polycarboxylate polymer, and optional additional ingredients to 100 % by weight, said method comprising preparing an aqueous slurry comprising zeolite, and polycarboxylate polymer and optional additional ingredients and spray drying the slurry, characterised in that the weight ratio of zeolite (anhydrous basis) to polycarboxylate polymer in the slurry is from 4:1 to 1:2.
In a preferred embodiment, the level of polycarboxylate polymer in the particles produced is from 15 to 50 wt % and of zeolite (anhydrous basis) is 10 to 50 wt %, or 29 to 50 wt%. A preferred additional ingredient comprises sodium carbonate.
In a further embodiment of the invention, detergent compositions comprising particles made by this process are defined. The inventors have found that detergent compositions comprising the particles made according to this invention also provide improved cleaning under cold water conditions when compared with the same compositions in which the polymeric polycarboxylate is added as a separate granule. This is surprising in view of the suppliers trade literature and teachings such as EP-A-658189 and EP-A-759463 which teach the use of granules of these polymeric materials in contrast to incorporating them via spray-drying processes.

Detailed Description of the Invention

The polycarboxylate polymers include homopolymers or copolymers. Suitable polymers include homopolymers or copolymers of dicarboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, citraconic acid and the derivatives of such acids including anhydrides of dicarboxylic acids, such as maleic anhydride; monocarboxylic acids such as acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid and acryloxypropionic acid.
Polymers can be in acid or neutralized or partially neutralized form with Na, K, or other counterions. Preferred polycarboxylate polymers are homopolymers of acrylic acid and copolymers of acrylic and maleic acids. Especially preferred are the acrylic/maleic copolymers available from BASF as Sokalan (tradename) CP5 and CP7 (salt form) and CP45 (acid form).
The average molar mass Mw of the polymers is typically from 500 to 5,000,000. Preferably the molecular weight will be above 10 000, more preferably above 20 000. The molecular weight may be below 1 000 000, but is usually below 500 000 or even 100 000.
Preferably the polymer will have a Brookfield viscosity (measured on a Brookfield LVT with a 20% solution of active substance in distilled water at 23°C, spindle 1 at 60rpm) of from 25 to 60, preferably 30 to 50.
The amount of polymeric polycarboxylate in the particles produced by the present invention is from 12 to 75 % by weight, or even from 15 to 50 % by weight and the quantities incorporated into the slurry for spray drying is selected accordingly. The quantities of polymer defined in this patent application are based on the equivalent fully neutralised sodium salt form of the polymer; for acid forms of polymer or other salt forms, the amounts used should be adjusted accordingly to be within the ranges defined.
The zeolite (alkali metal aluminosilicate) is present in an amount of from 10 to 54 wt % (based on anhydrous material). Preferably there will be at least 12 wt % and more preferably at least 15 wt % or at least 20 wt % zeolite or even at least 29 wt % based on the weight of the particle. The particle may comprise no greater than 50 wt % or even less than 40 wt % zeolite (anhydrous basis). The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula: 0.8-1.5 Na₂O. Al₂O₃. 0.8-6 SiO_2. These materials contain some bound water.
Suitable zeolites are described for example, in GB 1 473 201 (Henkel) and GB 1 429 143 (Procter & Gamble). The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A, X and P, and mixtures thereof. The zeolite may be the the commercially available zeolite 4A now widely used in laundry detergent powders. The zeolite builder incorporated in the compositions of the invention may be maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070B (Unilever). Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 1.15.
The weight ratio of the zeolite to the polycarboxylate polymer in the slurry for spray-drying is from 4:1 to 1:2, preferably from 3:1 to 1:1 and most preferably from 3:1 to 1.5:1. Particles having such a weight ratio have been found to provide a cleaning benefit when used in combination with other cleaning components in a fully formulated laundry detergent.
In a further advantageous embodiment of the invention, preferably the spray dried particle also comprises from 0.05 to 50 wt %, or 0.5 to 18 wt% or even 2 to 15 wt% of a shear thinning component. At higher levels, the viscosity is too low for effective spray-drying processes. This may be any shear-thinning detergent additive. It may be a hydrotrope or wax but is preferably a soap. Any conventional soap may be used. The shear-thinning component It is preferably added to the spray drying process by incorporation of solid particles which may be flakes or noodles or other solid particles of soap into the slurry for spray-drying. Alternatively, where the slurry is sufficiently alkaline to form the soap salt in situ, a fatty acid may be added to the slurry to generate soap in situ. The inventors have found an additional surprising benefit associated with the use of shear-thinning components comprising soap; soap is often associated with a problem of residues on laundered clothes particularly noticeable on dark-coloured fabrics. The inventors have found that incorporation of the soap into the particles of the present invention produces a significant benefit in reducing these residues.
In a further embodiment of the invention, surfactant is present in the slurry for spray-drying. Surfactants may be added directly to the slurry for spray-drying or the acid precursors of the anionic surfactants may be used so that the surfactant is formed in situ, as described above for in situ soap formation. Any desired level of surfactant may be present, but where present surfactant is generally added into the slurry for spray-drying in an amount to result in an amount of surfactant in the finished particle of from 1 to 50 wt%, or from 2 to 35 or 15 or even to 10 wt% based on the weight of the finished particle.
Suitable surfactants may be any used in detergent compositions as described below. Preferred are the anionic surfactants described below, particularly alkyl benzene sulphonate surfactants.
In addition it has been found to be highly advantageous for processing of the slurry and for producing well-structured particles to incorporate into the slurry for spray-drying a viscosity modifier.
In addition, a highly preferred component for addition to the slurry is a cationic amine component, particularly for example alkoxylated cationic diamines, polyamines or polymers of mixtures thereof, particularly as described in EP-A-111965. It has been found that such components not only provide a clay soil removal/anti-redeposition benefit in the final cleaning composition but also help in the processing of the slurry and in providing well-structured particles. Particularly preferred cationic amine components are optionally sulphated or sulphonated and selected from the group consisting of:
1) ethoxylated cationic monoamines having the formula:
2) ethoxylated cationic diamines having the formula:
or
wherein M¹ is an N+ or N group; each M² is an N+ or N group, and at least one M² is an N+ group;
3) ethoxylated cationic polyamines having the formula:
4) mixtures thereof;

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In a further embodiment of the invention, chelants or mixtures of chelants are present in the particles of the invention, generally at levels from 0 to 45 wt %, preferably at levels from 1 to 20 wt % or even 2 to 15 wt %. Suitable chelants can be selected from the group consisting of carboxylates, phosphonates, polyfunctionally-substituted aromatic chelants and mixtures thereof. The chelant is preferably a phosphonic acid or succinic acid, or salt thereof.
Useful carboxylates include ethylenediaminetetracetates ("EDTA"), N-hydroxyethylethylene diaminetriacetates, nitrilotriacetates, ethylene diamine tetraproprionates, triethylene tetraaminehexacetates, diethylenetriaminepentaacetates, and ethanoldiglycines, alkali metal, ammonium, and substituted ammonium salts thereof, and mixtures thereof.
Useful phosphonates include ethylenediaminetetrakis (methylenephosponates), sold as DEQUEST®. Preferably these amino phosphonates do not contain alkyl or alkenyl groups with more than about 6 carbon atoms. Particularly preferred chelants are diethylene triamine penta (methylene phosphonic acid) ("DTPMP") and ethylene diamine tetra (methylene phosphonic acid) (EDTMP) and hydroxyethylenediphosphonate (HEDP).
Polyfunctionally-substituted aromatic chelants are also useful in the components herein. See US-A- 3 812 044, issued May 21, 1974, to Connor et al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.
A preferred biodegradable chelant for use herein is ethylene diamine-N, N-disuccinate ("EDDS"), especially the [S,S] isomer as described in US-A-4 704 233, issued on November 3, 1987, to Hartman and Perkins.
Magnesium salts, particularly magnesium sulphate, have been found to be useful in ensuring efficient processing in the spray drying process. In particular when chelant is present in the particles of the invention, preferably a magnesium salt is also present. Generally the magnesium salt will be present at levels of from 0-40 wt % of the particle, preferably 0.1 to 10 wt %, more preferably from 0.5 to 5 wt %. Magnesium sulphate is particularly preferred. The chelating agent may be pre-complexed with a metal salt such as magnesium in order to provide some protection from degradation in the presence of bleach. Preferably this is done by dissolving a salt of the metal ion into a solution of the chelating agent in the required ratios. The molar ratio of metal ion to chelating agent is preferably at least 1:1, the present invention allows molar ratios of greater than 3:1 to be prepared, most preferred is a molar ratio of about 5:1. Again, whilst any metal salt may be used, magnesium sulphate is most preferred.
The particles of the present invention generally also contain an additional inorganic component such as sodium carbonate, phosphate or silicate. Sodium carbonate and/or silicate are preferred, sodium carbonate being most preferred. Such an inorganic component is preferably added in amounts from 0 up to 30 wt%, generally in amounts from 1 to 20 wt% or from 2 to 15 wt%.
In a further embodiment of the invention, the particles additionally contain other ingredients which are incorporated in detergent compositions in minor amounts, such as at levels below 10 wt%, more usually below 5 wt%, or even below 2 wt% or even lower in the finished detergent product. Examples of such materials include polymers useful in detergent compositions such as soil release polymers, optical brighteners, dye-transfer inhibitors ( such as PVP, PVNO, PVPVI and combinations thereof), anti-redeposition agents such as CMC, etc. In particular the present invention is useful for incorporating into a detergent composition components which are used at low levels in finished product and which are available from suppliers in an aqueous-based form such as a solution of suspension or dispersion in water. These materials can be added directly to the slurry for spray-drying.
The particles of the present invention are made by a spray-drying process. The polymer, zeolite and optional additional ingredients are mixed with water to form a slurry which is then spray-dried by conventional means (usually using warm air drying although spray cooling may also be useful). Generally this will be in a spray-drying tower using a high pressure (e.g. 6000-7000kPa) spray nozzle. Spinning disc atomisers may also be used. Generally raw materials which are provided by suppliers in solution or dispersion in water are pre-mixed and the solids including zeolite subsequently added.
The particles produced will generally have a bulk density at least 300g/l or at least 400 g/l and up to 1000g/l or 900g/l or below (as measured by the method now described). The final density of the particles and compositions herein can be measured by a simple technique which involves dispensing a quantity of the granular material into a container of known volume, measuring the weight of material and reporting the density as grams/liter. The method used herein allows the material to flow into the measuring container under gravity, and without pressure or other compaction in the measuring container. The density measurements should be run at room temperature. The granular material whose density is being measured should be at least 24 hours old and should be held at room temperature for 24 hours prior to testing. A relative humidity of 50 % or less is convenient. Of course, any clumps in the material should be gently broken up prior to running the test. The sample of material is allowed to flow through a funnel mounted on a filling hopper and stand (#150; Seedburo Equipment Company, Chicago, Illinois) into an Ohaus cup of known volume and weight (#104; Seedburo). The top of the cup is positioned about 50 mm from the bottom of the funnel, and the cup is filled to overflowing. A spatula or other straight edge is then scraped over the top of the cup, without vibration or tapping, to level the material, thereby exactly and entirely filling the cup. The weight of material in the cup is then measured. Density can be reported as g/l. Two repeat runs are made and the bulk density is reported as an average of the three measurements. Relative error is about 0.4 %.
In a further embodiment of the invention the particles are further processed to incorporate them into conventional granules such as agglomerates or extrudates. In this embodiment of the invention, any solid particulate in a conventional granulation process is wholly or partially replaced by the spray-dried particles of the present invention. Suitable conventional and known granulation processes include using a pan-granulator, fluidized bed, Schugi mixer, Lödige ploughshare mixer, rotating drum or other low energy mixers, marumeriser or spheroniser; by compaction, including extrusion optionally with spheronising or marumerising, and tabletting; when melt binding agents are used by prilling and pastilling using a Sandvik Roto Former; and by high shear processes in which the mixers have a high speed stirring and cutting action. Suitable mixers will be well known to those skilled in the art.
Suitable processes are described in the patent literature: an example of an agglomeration process is described in US 5133924 (Appel). An example of a suitable fluidised bed agglomeration process is described for example in WO97/22685 (Dhanuka). Suitable extrusion processes are described for example in WO97/03181 (EP-A-840780) (Henkel) or in EP-A-518888 (Henkel).

Detergent compositions incorporating the Particles.

In accordance with a further embodiment of the invention, there is provided a detergent composition comprising a particle as described above. Suitable detergent compositions may be for any cleaning purpose, but the invention is particularly directed to laundry washing applications. The detergent composition will generally be in the form of a solid composition. Solid compositions include powders, granules, noodles, flakes, bars, tablets, and combinations thereof. The detergent composition may be in the form of a liquid composition. The detergent composition may also be in the form of a paste, gel, liqui-gel, suspension, or any combination thereof. The detergent composition may be at least partially enclosed, preferably completely enclosed, by a film or laminate such as a water-soluble and/or water-dispersible material. Preferred water-soluble and/or water-dispersible materials are polyvinyl alcohols and/or carboxymethyl celluloses.
The detergent compositions of the invention are preferably granular detergents having an overall bulk density of from 350 to 1000 g/l, more preferably 550 to 1000g/l or even 600 to 900g/l. Generally the particles of the invention will be mixed with other detergent particles including combinations of agglomerates, spray-dried powders and/or dry added materials such as bleaching agents, enzymes etc, to provide a level of polycarboxylate polymer in the finished product from 0.1 or from 1 wt% based on finished product up to 10 wt%, or up to 7 wt% or even up to 5 wt%. Generally this means that the particles of the invention may be added into a detergent composition in amounts generally from 1 to 30 wt% based on finished product, or from 1 to 20 wt% or from 1 to 10 wt% based on finished product.
Preferably, the detergent particles or the composition has a size average particle size of from 200µm to 2000µm, preferably from 350µm to 600µm.
As described above, detergent compositions comprising the particles made by the process of the invention will comprise at least some of the usual detergent adjunct materials, such as agglomerates, extrudates, other spray dried particles having different composition to those of the invention, or dry added materials. Conventionally, surfactants are incorporated into agglomerates, extrudates or spray dried particles along with solid materials, usually builders, and these may be admixed with the spray dried particles of the invention. However, as described above some or all of the solid material may be replaced with the particles made according to the invention.
The detergent adjunct materials are typically selected from the group consisting of detersive surfactants, builders, polymeric co-builders, bleach, chelants, enzymes, anti-redeposition polymers, soil-release polymers, polymeric soil-dispersing and/or soil-suspending agents, dye-transfer inhibitors, fabric-integrity agents, suds suppressors, fabric-softeners, flocculants, perfumes, whitening agents, photobleach and combinations thereof.
The precise nature of these additional components, and levels of incorporation thereof will depend on the physical form of the composition or component, and the precise nature of the washing operation for which it is to be used.
A highly preferred adjunct component is a surfactant. Preferably, the detergent composition comprises one or more surfactants. Typically, the detergent composition comprises (by weight of the composition) from 0% to 50%, preferably from 5% and more preferably from 10 or even 15 wt% to 40%, or to 30%, or to 20% one or more surfactants. Preferred surfactants are anionic surfactants, non-ionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, cationic surfactants and mixtures thereof.
Preferred anionic surfactants comprise one or more moieties selected from the group consisting of carbonate, phosphate, sulphate, sulphonate and mixtures thereof. Preferred anionic surfactants are C_8-18 alkyl sulphates and C_8-18 alkyl sulphonates. Suitable anionic surfactants incorporated alone or in mixtures in the compositions of the invention are also the C_8-18 alkyl sulphates and/or C_8-18 alkyl sulphonates optionally condensed with from 1 to 9 moles of C_1-4 alkylene oxide per mole of C_8-18 alkyl sulphate and/or C_8-18 alkyl sulphonate. The alkyl chain of the C_8-18 alkyl sulphates and/or C_8-18 alkyl sulphonates may be linear or branched, preferred branched alkyl chains comprise one or more branched moieties that are C_1-6 alkyl groups. Other preferred anionic surfactants are C_8-18 alkyl benzene sulphates and/or C_8-18 alkyl benzene sulphonates. The alkyl chain of the C_8-18 alkyl benzene sulphates and/or C_8-18 alkyl benzene sulphonates may be linear or branched, preferred branched alkyl chains comprise one or more branched moieties that are C_1-6 alkyl groups.
Other preferred anionic surfactants are selected from the group consisting of: C_8-18 alkenyl sulphates, C_8-18 alkenyl sulphonates, C_8-18 alkenyl benzene sulphates, C_8-18 alkenyl benzene sulphonates, C_8-18 alkyl di-methyl benzene sulphate, C_8-18 alkyl di-methyl benzene sulphonate, fatty acid ester sulphonates, di-alkyl sulphosuccinates, and combinations thereof. The anionic surfactants may be present in the salt form. For example, the anionic surfactant may be an alkali metal salt of one or more of the compounds selected from the group consisting of: C_8-18 alkyl sulphate, C_8-18 alkyl sulphonate, C_8-18 alkyl benzene sulphate, C₈-C₁₈ alkyl benzene sulphonate, and combinations thereof. Preferred alkali metals are sodium, potassium and mixtures thereof. Typically, the detergent composition comprises from 10% to 30wt% anionic surfactant.
Preferred non-ionic surfactants are selected from the group consisting of: C_8-18 alcohols condensed with from 1 to 9 of C₁-C₄ alkylene oxide per mole of C_8-18 alcohol, C_8-18 alkyl N-C_1-4 alkyl glucamides, C_8-18 amido C_1-4 dimethyl amines, C_8-18 alkyl polyglycosides, glycerol monoethers, polyhydroxyamides, and combinations thereof. Typically the detergent compositions of the invention comprises from 0 to 15, preferably from 2 to 10 wt% non-ionic surfactant.
Preferred cationic surfactants are quaternary ammonium compounds. Preferred quaternary ammonium compounds comprise a mixture of long and short hydrocarbon chains, typically alkyl and/or hydroxyalkyl and/or alkoxylated alkyl chains. Typically, long hydrocarbon chains are C_8-18 alkyl chains and/or C_8-18 hydroxyalkyl chains and/or C_8-18 alkoxylated alkyl chains. Typically, short hydrocarbon chains are C_1-4 alky chains and/or C_1-4 hydroxyalkyl chains and/or C_1-4 alkoxylated alkyl chains. Typically, the detergent composition comprises (by weight of the composition) from 0% to 20% cationic surfactant.
Preferred zwitterionic surfactants comprise one or more quaternized nitrogen atoms and one or more moieties selected from the group consisting of: carbonate, phosphate, sulphate, sulphonate, and combinations thereof. Preferred zwitterionic surfactants are alkyl betaines. Other preferred zwitterionic surfactants are alkyl amine oxides. Catanionic surfactants which are complexes comprising a cationic surfactant and an anionic surfactant may also be included. Typically, the molar ratio of the cationic surfactant to anionic surfactant in the complex is greater than 1:1, so that the complex has a net positive charge.
A further preferred adjunct component is a builder. Preferably, the detergent composition comprises (by weight of the composition and on an anhydrous basis) from 5% to 50% builder. Preferred builders are selected from the group consisting of: inorganic phosphates and salts thereof, preferably orthophosphate, pyrophosphate, tri-poly-phosphate, alkali metal salts thereof, and combinations thereof; polycarboxylic acids and salts thereof, preferably citric acid, alkali metal salts of thereof, and combinations thereof; aluminosilicates, salts thereof, and combinations thereof, preferably amorphous aluminosilicates, crystalline aluminosilicates, mixed amorphous/crystalline aluminosilicates, alkali metal salts thereof, and combinations thereof, most preferably zeolite A, zeolite P, zeolite MAP, salts thereof, and combinations thereof; silicates such as layered silicates, salts thereof, and combinations thereof, preferably sodium layered silicate; and combinations thereof.
A preferred adjunct component is a bleaching agent. Preferably, the detergent composition comprises one or more bleaching agents. Typically, the composition comprises (by weight of the composition) from 1% to 50% of one or more bleaching agent. Preferred bleaching agents are selected from the group consisting of sources of peroxide, sources of peracid, bleach boosters, bleach catalysts, photo-bleaches, and combinations thereof. Preferred sources of peroxide are selected from the group consisting of: perborate monohydrate, perborate tetrahydrate, percarbonate, salts thereof, and combinations thereof. Preferred sources of peracid are selected from the group consisting of: bleach activator typically with a peroxide source such as perborate or percarbonate, preformed peracids, and combinations thereof. Preferred bleach activators are selected from the group consisting of: oxy-benzene-sulphonate bleach activators, lactam bleach activators, imide bleach activators, and combinations thereof. A preferred source of peracid is tetra-acetyl ethylene diamine (TAED)and peroxide source such as percarbonate. Preferred oxy-benzene-sulphonate bleach activators are selected from the group consisting of: nonanoyl-oxy-benzene-sulponate, 6-nonamido-caproyl-oxy-benzene-sulphonate, salts thereof, and combinations thereof. Preferred lactam bleach activators are acyl-caprolactams and/or acyl-valerolactams. A preferred imide bleach activator is N-nonanoyl-N-methyl-acetamide.
Preferred preformed peracids are selected from the group consisting of N,N-pthaloyl-amino-peroxycaproic acid, nonyl-amido-peroxyadipic acid, salts thereof, and combinations thereof. Preferably, the STW-composition comprises one or more sources of peroxide and one or more sources of peracid. Preferred bleach catalysts comprise one or more transition metal ions. Other preferred bleaching agents are di-acyl peroxides. Preferred bleach boosters are selected from the group consisting of: zwitterionic imines, anionic imine polyions, quaternary oxaziridinium salts, and combinations thereof. Highly preferred bleach boosters are selected from the group consisting of: aryliminium zwitterions, aryliminium polyions, and combinations thereof. Suitable bleach boosters are described in US360568, US5360569 and US5370826.
A preferred adjunct component is an anti-redeposition agent. Preferably, the detergent composition comprises one or more anti-redeposition agents. Preferred anti-redeposition agents are cellulosic polymeric components, most preferably carboxymethyl celluloses.
A preferred adjunct component is a chelant. Preferably, the detergent composition comprises one or more chelants. Preferably, the detergent composition comprises (by weight of the composition) from 0.01% to 10% chelant. Preferred chelants are selected from the group consisting of: hydroxyethane-dimethylene-phosphonic acid, ethylene diamine tetra(methylene phosphonic) acid, diethylene triamine pentacetate, ethylene diamine tetraacetate, diethylene triamine penta(methyl phosphonic) acid, ethylene diamine disuccinic acid, and combinations thereof.
A preferred adjunct component is a dye transfer inhibitor. Preferably, the detergent composition comprises one or more dye transfer inhibitors. Typically, dye transfer inhibitors are polymeric components that trap dye molecules and retain the dye molecules by suspending them in the wash liquor. Preferred dye transfer inhibitors are selected from the group consisting of: polyvinylpyrrolidones, polyvinylpyridine N-oxides, polyvinylpyrrolidone-polyvinylimidazole copolymers, and combinations thereof.
A preferred adjunct component is an enzyme. Preferably, the detergent composition comprises one or more enzymes. Preferred enzymes are selected from then group consisting of: amylases, arabinosidases, carbohydrases, cellulases, chondroitinases, cutinases, dextranases, esterases, β-glucanases, gluco-amylases, hyaluronidases, keratanases, laccases, ligninases, lipases, lipoxygenases, malanases, mannanases, oxidases, pectinases, pentosanases, peroxidases, phenoloxidases, phospholipases, proteases, pullulanases, reductases, tannases, transferases, xylanases, xyloglucanases, and combinations thereof. Preferred enzymes are selected from the group consisting of: amylases, carbohydrases, cellulases, lipases, proteases, and combinations thereof.
A preferred adjunct component is a fabric integrity agent. Preferably, the detergent composition comprises one or more fabric integrity agents. Typically, fabric integrity agents are polymeric components that deposit on the fabric surface and prevent fabric damage during the laundering process. Preferred fabric integrity agents are hydrophobically modified celluloses. These hydrophobically modified celluloses reduce fabric abrasion, enhance fibre-fibre interactions and reduce dye loss from the fabric. A preferred hydrophobically modified cellulose is described in WO99/14245. Other preferred fabric integrity agents are polymeric components and/or oligomeric components that are obtainable, preferably obtained, by a process comprising the step of condensing imidazole and epichlorhydrin.
A preferred adjunct component is a salt. Preferably, the detergent composition comprises one or more salts. The salts can act as alkalinity agents, buffers, builders, co-builders, encrustation inhibitors, fillers, pH regulators, stability agents, and combinations thereof. Typically, the detergent composition comprises (by weight of the composition) from 5% to 60% salt. Preferred salts are alkali metal salts of aluminate, carbonate, chloride, bicarbonate, nitrate, phosphate, silicate, sulphate, and combinations thereof. Other preferred salts are alkaline earth metal salts of aluminate, carbonate, chloride, bicarbonate, nitrate, phosphate, silicate, sulphate, and combinations thereof. Especially preferred salts are sodium sulphate, sodium carbonate, sodium bicarbonate, sodium silicate, sodium sulphate, and combinations thereof. Optionally, the alkali metal salts and/or alkaline earth metal salts may be anhydrous.
A preferred adjunct component is a soil release agent. Preferably, the detergent composition comprises one or more soil release agents. Typically, soil release agents are polymeric compounds that modify the fabric surface and prevent the redeposition of soil on the fabric. Preferred soil release agents are copolymers, preferably block copolymers, comprising one or more terephthalate unit. Preferred soil release agents are copolymers that are synthesised from dimethylterephthalate, 1,2-propyl glycol and methyl capped polyethyleneglycol. Other preferred soil release agents are anionically end capped polyesters.
A preferred adjunct component is a soil suspension agent. Preferably, the detergent composition comprises one or more soil suspension agents. Preferred soil suspension agents are polymeric polycarboxylates. Especially preferred are polymers derived from acrylic acid, polymers derived from maleic acid, and co-polymers derived from maleic acid and acrylic acid. In addition to their soil suspension properties, polymeric polycarboxylates are also useful co-builders for laundry detergents. Other preferred soil suspension agents are alkoxylated polyalkylene imines. Especially preferred alkoxylated polyalkylene imines are ethoxylated polyethylene imines, or ethoxylated-propoxylated polyethylene imine. Other preferred soil suspension agents are represented by the formula: bis((C₂H₅O)(C₂H₄O)_n)(CH3)-N⁺-C_xH_2x-N⁺-(CH₃)-bis((C₂H₄O)_n(C₂H₅O)), wherein, n=from 10 to 50 and x=from 1 to 20. Optionally, the soil suspension agents represented by the above formula can be sulphated and/or sulphonated.

Softening system

The detergent compositions of the invention may comprise softening agents for softening through the wash such as clay optionally also with flocculant and enzymes.
Further more specific description of suitable detergent components can be found in WO97/11151.

Examples

The following are examples of the invention.

Example A

Raw Material	% slurry
	Example 1	Example 2
EDDS (ethylenediamine -N,N'-disuccinic acid (S,S isomer) in the form of its sodium salt)	2.8
MgSO4	1.1	-
Na₂SO₄	-	0.7
Maleic acid/acrylic acid copolymer (salt form) Sokalan CP5 (tradename from BASF)	10.8	13.0
HEDP (1,1-hydroxyethane diphosphonic acid)	5.6	3.1
C_12-18 alkyl benzene sulphonate (Na salt) LAS	-	3.1
Soap	6.5	-
Zeolite (anhydrous basis)	37.0	30.4
Hexamethylene diaminetetra (ethoxylate₂₄) diquat with MeCl	-	2.5
Miscellaneous	5.6	7.2
Water	30.6	40.0
Total parts	100.0	100.0

A homogeneous aqueous slurry of the components shown above was made up with the moisture content shown. The slurry was heated to 80°C and fed under high pressure, (6,000-7,000 kPa), into a conventional counter-current spray drying tower with an air inlet temperature of 300-310°C. The atomised slurry was dried to produce a granular solid which was then cooled and sieved to remove oversize (>2mm). Fine (<0.15mm) material was elutriated with the exhaust air in the spray-drying tower and collected in a containment system. The finished granules had a moisture content of about 10% by weight, a bulk density of 383 g/l and a particle size distribution such that 56.4% by weight of the granules were between 150-710 microns in size. The particles formed were free-flowing.The spray-dried powder had a composition as shown in table 2 below.

Raw Material	% Spray dried granule
	Example 1	Example 2
EDDS	3.7	-
MgSO4	1.5	-
Na₂SO₄	-	1.1
MA/AA (Sokalan CP5)	14.0	21.0
HEDP	7.3	5.0
LAS	-	5.0
Soap	8.4	-
Zeolite A	47.9	49.0
Diamine	-	4.0
Miscellaneous	7.4	4.9
Water	9.8	10.0
Total Parts	100	100

These particles of example A (A(1) or A(2)) are incorporated into the following solid laundry detergent compositions according to the invention (Table 3). Amounts given below are percentages by weight of the fully formulated detergent composition.

Ingredient	A	B	C	D	E
Example A particles	7%	13%	15%	10%	10%
Sodium linear C_11-13 alkylbenzene sulfonate	11%	12%	10%	18%	15%
R₂N⁺(CH₃)₂(C₂H₄OH), wherein R₂ = C_12-14 alkyl group	0.6%	1%			0.6%
Sodium C_12-18 linear alkyl sulfate condensed with an average of 3 to 5 moles of ethylene oxide per mole of alkyl sulfate		0.3%	2%	2%
Mid chain methyl branched sodium C_12-C₁₄ linear alkyl sulfate	1.4%	1.2%	1%
Sodium C_12-18 linear alkyl sulfate	0.7%	0.5%
C_12-18 linear alkyl ethoxylate condensed with an average of 3-9 moles of ethylene oxide per mole of alkyl alcohol		3%	2%
Citric acid	2%	1.5%			2%
Sodium tripolyphosphate (anhydrous weight given)			20%	25%	22%
Sodium carboxymethyl cellulose	0.2%	0.2%		0.3%
Sodium polyacrylate polymer having a weight average molecular weight of from 3000 to 5000		0.5%	1%		0.7%
Copolymer of maleic/acrylic acid, having a weight average molecular weight of from 50,000 to 90,000, wherein the ratio of maleic to acrylic acid is from 1:3 to 1:4 (Sokalan CP5 from BASF)	1.2%	0.5%
Diethylene triamine pentaacetic acid	0.2%		0.5%	0.2%	0.3%
Proteolytic enzyme having an enzyme activity of from 15 mg/g to 70 mg/g	0.2%	0.2%	0.5%	0.4%	0.3%
Amyolitic enzyme having an enzyme activity of from 25 mg/g to 50 mg/g	0.2%	0.2%	0.3%	0.4%	0.3%
Lipolytic enzyme having an enzyme activity of 5 mg/g to 25 mg/g		0.2%	0.1%
Anhydrous sodium perborate monohydrate			20%	5%	8%
Sodium percarbonate	10%	12%
Magnesium sulfate
Nonanoyl oxybenzene sulfonate				2%	1.2%
Tetraacetylethylenediamine	3%	4%	2%	0.6%	0.8%
Brightener	0.1%	0.1%	0.2%	0.1%	0.1%
Sodium carbonate	10%	10%	10%	19%	22%
Sodium sulfate	20%	15%	5%	13%	1%
Zeolite A	20%	15%		2%	14%
Sodium silicate (2.0 R)		0.2%		1%	1%
Crystalline layered silicate	3%	5%	10%
Photobleach	0.002%
Polyethylene oxide having a weight average molecular weight from 100 to 10,000	2%	1%
Perfume spray-on	0.2%	0.5%	0.25%	0.1%
Starch encapsulated perfume	0.4%
Silicone based suds suppressor	0.05%	0.05%			0.02%
Miscellaneous and moisture	To 100%	To 100%	To 100%	To 100%	To 100%

Claims

A method for making a laundry detergent particle comprising from 10 to 60 wt % (anhydrous basis) zeolite, from 12 to 75 wt % polycarboxylate polymer, and optional additional ingredients to 100 % by weight, said method comprising preparing an aqueous slurry comprising zeolite, and polycarboxylate polymer and optional additional ingredients and spray drying the slurry, characterised in that the weight ratio of zeolite (anhydrous basis) to polycarboxylate polymer in the slurry is from 4:1 to 1:2.
A method according to claim 1 in which the slurry is prepared by adding zeolite to an aqueous solution comprising polycarboxylate polymer.
A method according to claim 1 or claim 2 in which the spray-dried particle comprises 15 to 50 wt% polycarboxylate polymer (salt form).
A method according to any preceding claim in which the polycarboxylate polymer has a molecular weight greater than 10 000.
A method according to any preceding claim in which a shear-thinning component, preferably soap is added into the slurry in an amount to produce a level of soap in the spray-dried particle of 0.05 to 20 wt %, preferably 0.5 to 18 wt%.
A method according to any preceding claim in which the particle produced comprises zeolite (anhydrous basis) in an amount of from 29 % by weight to no more than 54 or even 40 % by weight based on the total weight of the particle.
A method according to any preceding claim in which the slurry for spray-drying also comprises an alkoxylated cationic diamine, alkoxylated cationic polyamine or alkoxylated cationic polymer or mixtures thereof, optionally sulphated or sulphonated.
A method according to any preceding claim in which the slurry for spray-drying additionally comprising chelant, preferably phosphonate or succinate chelant.
A method according to any preceding claim in which the slurry for spray-drying additionally comprises a magnesium salt, preferably in an amount such that the finished particle will comprise magnesium in an amount equivalent to 0.5 to 5 % by weight magnesium sulphate.
A detergent composition comprising spray-dried particles prepared according to any preceding claim and surfactant-containing detergent particles comprising from 10 to 60 % by weight surfactant.
A detergent composition according to claim 10 in which the surfactant-containing detergent particles are spray-dried particles, agglomerates or extrudates.
A detergent composition according to claim 10 in which the spray-dried particles are incorporated into the detergent composition as part of an agglomerate or extrudate with other detergent adjunct ingredients.
A detergent composition according to claim 10 additionally comprising a soil suspension agent of the formula: bis((C₂H₅O)(C₂H₄O)_n)(CH3)-N⁺-C_xH_2x-N⁺-(CH₃)-bis((C₂H₄O)_n(C₂H₅O)), wherein, n=from 10 to 50 and x=from 1 to 20.