The process for preparing flattened, spray-dried detergent particles.

Abstract

The present invention relates to a process for preparing a particulate, free flowing detergent particle by a slurry making and spray drying technique. It is thus an object of the present invention to provide a process for preparing a detergent solution for a spray-dried detergent particle which provides for incorporating a carbonate builder and silicate salt at optimum levels whilst provides good cleaning performance and good powder properties. The present inventors have surprisingly found that a spray-dried detergent particle exhibits extended shelf life and demonstrates excellent powder properties without getting caked during use, when the spray dried detergent particle is prepared by a process where an in-situ silicate and / or a disilicate a salt of an alkaline earth metal is formed by reacting an alkali metal silicate with an alkaline earth metal salt, and the spray dried detergent particle also includes an alkali metal silicate salt along with optimum detersive surfactant content, filler and carbonate builder, wherein the composition preferably has no phosphate builder and zeolite builder.

Description

[0001] PROCESS FOR PREPARING A SPRAY DRIED DETERGENT PARTICLE

[0002] Field of the invention

[0003] The present invention relates to a process for preparing a particulate, free flowing detergent particle by a slurry making and spray drying technique. The spray-dried particle is suitable for use as a solid laundry detergent composition, or for incorporation into a solid laundry detergent composition.

[0004] Background of the invention

[0005] Typically, granular laundry detergent composition is prepared by spray-drying. In spray drying process the detergent components, such as surfactants and builders are mixed with around 20% to 50% by weight water to form an aqueous slurry, the aqueous slurry is maintained at temperatures ranging from 60°C to 85°C and then spray-dried in a spray-drying tower.

[0006] Lumping and caking of the spray-dried detergent composition has been a common problem faced by the consumers. There has been a continued effort towards improving the properties of the spray dried powder.

[0007] During use, the consumers generally store the solid laundry detergent composition close to the washing machine or the washing area. These regions are generally subjected to higher humidity. Further after opening the pouch containing the detergent composition, the consumers usually either empty the solid detergent composition into a container or store the powder along with the pouch in the container. However, during storage moisture ingress overtime into the solid detergent composition, which is either absorbed from the air, or transferred from the wet scoop used to dose the solid detergent composition.

[0008] Nowadays there is an increasing trend towards concentrating solid laundry detergent compositions loaded with high concentrations of cleaning agents or detersive surfactants, particularly with high concentration of anionic surfactants. Such concentrated solid laundry composition / spray dried detergent particle with at least 40 w.% surfactant content must also be free flowing to be dosed accurately and must retain good flow properties over extended storage life.

[0009] In carbonate-built spray-dried detergent particle, the presence of sulphate fillers in the aqueous slurry improves the powder properties by way of formation of burkeites.

[0010] However, in certain regions to meet the cost expectations instead of sodium sulphate, hygroscopic fillers like sodium chloride is extensively being used. Another reason for finding alternates to sodium sulphate as filler in a spray-dried particle is because natural sulphate have high bulk density and upon addition to water it rapidly sinks and forms a sediment, this sedimentation is associated with poor cleaning by the consumers. Any replacement of sodium sulphate with more hygroscopic fillers such as sodium chloride, calcium carbonate, magnesium carbonate, calcium magnesium carbonate or mixtures thereof is met with its own challenges as this replacement increases the tendency of the spray-dried particle to cake. With the use of hygroscopic fillers like sodium chloride, it is yet another challenge to sustain the free-flowing behaviour of the powder during extended storage periods.

[0011] Another reason for further improving the storage stability of a spray-dried detergent particle which is free-flowing for longer durations of storage is due to an increasing rise of providing consumer products in recyclable packaging material and the move towards more sustainable packaging solutions, such as paper-based packaging which offer lesser barrier to moisture, it is all the more important to provide a robust spray-dried detergent particle that can survive long storage conditions. It is therefore desired that the detergent composition, comprising a spray-dried detergent particle is formulated such that it provides for improved storage conditions and maintains it free flowing properties even over extended storage conditions.

[0012] US3849346 (Lion, 1974) discloses a process for preparing a granular detergent composition containing particles of relatively high mechanical strength and which are essentially non-caking. The process includes the step of spray-drying a slurry comprising anionic surface-active agent, sodium tripolyphosphate, sodium silicate and magnesium sulphate to form in-situ magnesium silicate and magnesium phosphate. More recently, WO 2006 / 029676 A1 (Unilever) discloses a laundry detergent composition with a soluble alkali metal silicate and 0.01 wt.% to 25 wt.% alkaline earth silicate seeds. The alkaline earth silicate seeds are formed in-situ by reaction of sodium silicate and soluble alkaline earth metal salt in presence of anionic surfactant during the laundry detergent base powder processing.

[0013] US 2009 / 325847 A1 (Tantawy Hossam Hassan) discloses a process for forming a spray-dried particle which has good stability profile. The aqueous slurry includes 4.32 wt.% sodium carbonate and forms a spray-dried detergent particle having magnesium sulphate, 5.77 wt.% sodium carbonate and 63.43 wt.% sodium sulphate.

[0014] US 3975280 A (Hachmann Klaus et. al. , 1976) discloses a washing composition with high stability on storage and where the embedded active agent does not lose its activity even on prolonged storage.

[0015] US 4139486 A (Bailey John et. al., 1979) discloses a detergent composition having superior whiteness maintenance and lower undesirable residual deposits on the fabrics which composition includes orthophosphate and pyrophosphate together as builder along with the addition of magnesium silicate.

[0016] WO 2005 / 037712 A1 (Osinga Theo Jan) discloses a detergent composition having a soluble carbonate salt in combination with a soluble alkali metal silicate. It discloses a method of preparing amorphous particles of silicate-based calcium salt or silicate- based magnesium salt having the step of mixing an aqueous solution of a calcium salt or magnesium salt with a soluble alkali metal silicate salt and a soluble carbonate salt.

[0017] EP 2138565 A1 (Procter & Gamble, 2009) discloses a spray-drying process where an alkaline slurry is formed in a mixer, and a portion of the acid anionic detersive surfactant precursor is contacted with the alkaline slurry after the mixer and before the spray pressure nozzle to form a mixture, the mixture is then sprayed through the spray pressure nozzle into the spray-drying tower to form a spray-dried powder. Thus, there is a need to provide a spray dried detergent particle having specific fillers while maintaining good powder properties such as free-flowing characteristic and anticaking properties over extended storage life and where such spray-dried particle has optimum levels of detersive surfactant along with carbonate builders and which are devoid of phosphate builder and preferably devoid of zeolite builders.

[0018] It is thus an object of the present invention to provide a process for preparing a spray- dried detergent particle which provides for incorporating a carbonate builder and silicate salt at optimum levels whilst provides good cleaning performance and good powder properties.

[0019] It is yet another object of the present invention to provide a process for preparing a detergent solution which upon spray drying provides for a spray-dried detergent particle having improved storage stability even in presence of hygroscopic fillers.

[0020] It is a further object of the present invention to provide a process for preparing a spray- dried particle which has a relatively better structure, but which do not have an increased tendency towards caking when packaged in a package with lower moisture barrier properties.

[0021] Summary of the invention

[0022] The present inventors have surprisingly found that a spray-dried detergent particle having hygroscopic fillers exhibits extended shelf life and demonstrates excellent powder properties without getting caked during use, when the spray dried detergent particle is prepared by a process where an in-situ silicate and / or a disilicate a salt of an alkaline earth metal is formed by reacting an alkali metal silicate with an alkaline earth metal salt, and the spray dried detergent particle also includes an alkali metal silicate salt along with optimum detersive surfactant content and carbonate builder, wherein the composition has no phosphate builder and preferably no zeolite builder.

[0023] The spray dried detergent particle according to the present invention preferably incorporates optimum amounts of alkaline builders, particularly alkali metal silicates and alkali metal carbonates. According to a first aspect of the present invention, disclosed is a process for preparing a spray-dried detergent particle, said process comprising the steps of:

[0024] (i) contacting an alkaline earth metal salt with an alkali metal silicate salt in an aqueous mixture comprising a detersive surfactant, wherein the alkaline earth metal salt reacts with the alkali metal silicate salt to form in-situ silicate salt and / or disilicate salt of alkaline earth metal;

[0025] (ii) adding sodium carbonate salt and a filler selected from the group consisting of alkali metal chloride, alkaline earth metal carbonate or mixtures thereof to the aqueous mixture to form an aqueous slurry, wherein the aqueous slurry comprises alkali metal silicate, in-situ formed silicate salt and / or disilicate salt of alkaline earth metal, detersive surfactant, filler, 0 wt.% phosphate builder and 10 wt.% to 62 wt.% sodium carbonate;

[0026] (iii) spray-drying said aqueous slurry to form said spray dried detergent particle.

[0027] Detailed description of the invention

[0028] Process of making a spray-dried detergent particle

[0029] According to a first aspect disclosed is a process of preparing a spray-dried detergent particle comprising the steps as described herein below.

[0030] Step (i): Contacting an alkaline earth metal salt with an alkali metal silicate

[0031] According to the first aspect of the present invention disclosed is a process of contacting an alkaline earth metal salt with an alkali metal silicate in an aqueous mixture. The aqueous mixture comprises a detersive surfactant.

[0032] Alkaline earth metal salt:

[0033] The alkaline earth metal salt is preferably a magnesium or a calcium salt or mixtures thereof. The alkaline earth metal salt may be preferably selected from calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride or mixtures thereof. Preferably the alkali earth metal is a magnesium salt selected from magnesium sulphate, magnesium chloride or mixtures thereof and still preferably the alkaline earth metal salt is magnesium sulphate. Alkali metal silicate:

[0034] The process according to the present invention includes addition of an alkali metal silicate to the aqueous mixture. Preferably the alkali metal silicate is a soluble silicate. Soluble silicates are common ingredients in the laundry detergent compositions. Some commercial grades of silicates may contain a trace level of alkaline earth metal silicate, as contamination. The composition of trace materials in the water used for making an aqueous mixture having detersive surfactant may also contribute to the alkaline earth metal. However, the amount of amorphous material introduced through this impurity route will be low. The spray-dried detergent particle prepared according to the process of the first aspect of the present invention preferably includes 0.1 wt.% to 2.5 wt.% amorphous alkaline earth metal silicate prepared in-situ.

[0035] The alkali metal silicate salt preferably has a weight ratio of SiC^I hO where M is an alkali metal, within the range of 1.6 to 3.3 more preferably 1.6 to 2.4, and most preferably 2.0 to 2.85. The alkali metal silicate salt employed is preferably in the form of an aqueous solution, generally having 30 wt.% to 45 wt.% solid content.

[0036] Preferably the alkali metal silicate salt may be selected from the group consisting of sodium silicate, potassium silicate, sodium-potassium double silicate or mixtures thereof. Preferably the alkali metal silicate salt is water-soluble. Preferably the alkali metal silicate salt employed is sodium silicate. Preferably the sodium silicate has a weight ratio, SiC>2:Na20 within the range of 1.6 to 3.3 more preferably 1.6 to 2.4, and most preferably 2.0 to 2.85. Preferably the amount of alkali metal silicate present in the aqueous mixture is in stoichiometric excess of the amount required for reacting with alkaline earth metal salt. Preferably the amount of alkali metal silicate present in the aqueous mixture is such that the spray dried detergent particle formed preferably comprises from 5 wt.% to 17 wt.% alkali metal silicate salt. The amount of alkali metal silicate added to the aqueous mixture is from 8 wt.% to 30 wt.% by weight of the aqueous mixture. Alternately, the excess amount of alkali metal silicate (after the formation of the in-situ alkaline earth metal silicate) may be added into the slurry at any stage before spray-drying, more preferably after the addition of filler. Preferably the weight ratio between the alkali metal silicate to the alkaline earth metal salt added to the aqueous mixture is in the range from 260:1 to 5:1, preferably 24:1 to 12:1. Aqueous mixture:

[0037] The aqueous mixture comprises a detersive surfactant.

[0038] Detersive surfactant: The aqueous mixture includes a detersive surfactant. The detersive surfactant is preferably an anionic surfactant. The detersive anionic surfactant is either pre-neutralized and added into the aqueous mixture or a liquid acid form of the anionic surfactant is added to the aqueous mixture and neutralized in-situ. Alternately, the acid form of the anionic surfactant may be partly neutralized and thereafter added into the aqueous mixture such that the remaining un-neutralized part of the liquid acid form of the anionic surfactant is neutralized in-situ in the aqueous mixture. Pre-neutralized surfactant is commercially available in solid form or in the form of paste. Preferably the detersive surfactant is added to the aqueous mixture before addition of the alkaline earth metal salt. In some embodiments the detersive surfactant is added to the aqueous mixture after addition of the alkaline earth metal salt or along with the alkaline earth metal salt. When the detersive surfactant is added into the aqueous mixture in the form of a partly neutralized surfactant, the partly neutralized anionic surfactant is preferably prepared by a neutralization process which involves the step of (i) mixing a liquid acid form of the anionic surfactant and a neutralizing agent to form a partially neutralized solution; preferably the neutralizing agent is an alkali metal hydroxide, wherein the amount of alkali metal hydroxide neutralizing agent is sufficient to react with a portion of liquid acid anionic surfactant precursor to form in-situ anionic surfactant salt. The neutralized anionic surfactant formed by neutralizing the acid form with the alkali metal hydroxide neutralizing agent contributes from 28 parts to 98 parts of the total anionic surfactant by weight present in the spray-dried particle. On addition of alkali metal silicate to the partly neutralized anionic surfactant in the aqueous mixture, the remaining unreacted acid form of the anionic surfactant reacts with the alkali metal silicate salt to form fully neutralized salt form of the anionic surfactant. In one embodiment of the present invention a fully neutralized anionic surfactant is added to the aqueous mixture. In this embodiment the liquid acid anionic surfactant precursor is reacted with an alkali metal hydroxide to form fully neutralized anionic surfactant salt before addition to the aqueous mixture. More preferably the liquid acid precursor of the anionic surfactant is partly or fully neutralized in-situ.

[0039] It is most preferred that the detersive surfactant is present when the alkaline earth metal salt is contacted with the alkali metal silicate salt. The order of addition is to contact the pre-neutralized detersive surfactant or the acid detersive surfactant precursor with water followed by contacting with the alkali metal silicate and then adding the alkaline earth metal salt. Preferably the part or full neutralization may be carried out in the same vessel by contacting the acid form of the anionic surfactant with an aqueous solution of neutralizing agent (alkali metal hydroxide) to form the neutralized anionic surfactant salt. Alternately in the process of the present invention, the order of addition may be reversed wherein the step involves adding alkaline earth metal salt to the aqueous mixture followed by the alkali metal silicate salt.

[0040] Suitable detersive surfactants include anionic detersive surfactants, non-ionic detersive surfactant, cationic detersive surfactants, zwitterionic detersive surfactants and amphoteric detersive surfactants. Suitable detersive surfactants may be linear or branched, substituted or un-substituted, and may be derived from sources well known to the person skilled in the art.

[0041] Preferably the detersive surfactant is an anionic surfactant. Suitable anionic detersive surfactants include sulphonate and sulphate surfactants. Suitable sulphonate surfactants include methyl ester sulphonate, alpha olefin sulphonate, alkyl benzene sulphonate, especially alkyl benzene sulphonate, preferably Cio to C13alkyl benzene sulphonate. A preferred detersive anionic surfactant is linear alkyl benzene sulphonate, where the alkyl chain has 5 to 20 carbon atoms, more preferably the linear alkylbenzene sulphonate surfactant has a C12 to C18alkyl group. Suitable alkyl benzene sulphonate (LAS) is obtainable, preferably obtained, by sulphonating commercially available linear alkyl benzene (LAB); suitable LAB includes low 2-phenyl LAB, other suitable LAB includes high 2-phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®. Suitable sulphate surfactants include alkyl sulphate, preferably Cs to Ci8alkyl sulphate, or predominantly C12 to Cis alkyl sulphate. One or more anionic surfactant may be present in the spray-dried detergent particle.

[0042] A preferred sulphate detersive surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a Cs to Cis alkyl alkoxylated sulphate, preferably a Cs to Cis alkyl ethoxylated sulphate, preferably the alkyl alkoxylated sulphate has an average degree of alkoxylation of from 0.5 to 20, preferably from 0.5 to 10, preferably the alkyl alkoxylated sulphate is a Cs to Cis alkyl ethoxylated sulphate having an average degree of ethoxylation of from 0.5 to 10, preferably from 0.5 to 5, more preferably from 0.5 to 3 and most preferably from 0.5 to 1.5. The alkyl sulphate, alkyl alkoxylated sulphate and alkyl benzene sulphonate may be linear or branched, substituted or un-substituted and may be derived from petrochemical material or biomaterial. Other suitable anionic detersive surfactants include, Soaps, alkyl ether carboxylates. Suitable anionic detersive surfactants may be in salt form, suitable counter-ions include sodium, calcium, magnesium, amino alcohols, and any combinations thereof. A preferred counterion is sodium. Preferably the detersive surfactant is anionic surfactant selected from alkyl benzene sulphonate, primary alkyl sulphate, secondary alkyl sulphate, alkyl ether sulphate or mixtures thereof, still preferably selected from linear alkyl benzene sulphonate, alkyl ether sulphate or mixtures thereof, still preferably selected from LAS, SLES or mixtures thereof.

[0043] Suitable non-ionic detersive surfactants are selected from the group consisting of: Cs to C18 alkyl ethoxylates, such as, NEODOL® non-ionic surfactants from Shell; C6to C12 alkyl phenol alkoxylates wherein preferably the alkoxylate units are ethyleneoxy units, propyleneoxy units or a mixture thereof; C12 to Cis alcohol and C6to C12 alkyl phenol condensates with ethylene oxide / propylene oxide block polymers such as Pluronic® from BASF; alkyl polysaccharides, preferably alkyl polyglycosides; methyl ester ethoxylates; polyhydroxy fatty acid amides; ether capped poly(oxyalkylated) alcohol surfactants and mixtures thereof.

[0044] Suitable non-ionic detersive surfactants are alkyl polyglucoside and / or an alkyl alkoxylated alcohol. Suitable non-ionic detersive surfactants include alkyl alkoxylated alcohols, preferably Cs to Cis alkyl alkoxylated alcohol, preferably a Cs to Cis alkyl ethoxylated alcohol, preferably the alkyl alkoxylated alcohol has an average degree of alkoxylation of from 1 to 50, preferably from 1 to 30, or from 1 to 20, or from 1 to 10, preferably the alkyl alkoxylated alcohol is a Cs to Cis alkyl ethoxylated alcohol having an average degree of ethoxylation of from 1 to 10, preferably from 1 to 7, more preferably from 1 to 5 and most preferably from 3 to 7. The alkyl alkoxylated alcohol can be linear or branched and substituted or un-substituted. Suitable nonionic detersive surfactants include secondary alcohol-based detersive surfactants. Zwitterionic surfactant: Suitable zwitterionic detersive surfactants include amine oxides and / or betaines.

[0045] One or more detersive surfactant may be present in the spray-dried particle according to the present invention. The surfactants are preferably those which are thermally stable during processing conditions of a tower with inlet air temperature ranging from 250°C to 500°C and those which are chemically stable at the pH conditions of the spray-drying slurry. Non-limiting examples of the anionic surfactant includes the ones mentioned above. Step (ii): Forming in-situ silicate salt or disilicate salt of alkaline earth metal

[0046] The alkali metal silicate reacts with the alkaline earth metal salt to form in-situ silicate or disilicate salt of alkaline earth metal or mixtures thereof. Preferably the alkaline earth metal salt present in the reaction is magnesium sulphate or magnesium chloride, more preferably magnesium sulphate. Preferably the magnesium sulphate reacts with alkali metal silicate to form in-situ magnesium silicate or magnesium disilicate or mixtures thereof. Preferably the alkali metal silicate is sodium silicate.

[0047] Preferably the reaction of the alkali metal silicate with the alkaline earth metal salt is carried out by heating the aqueous mixture in a mixer at a temperature of 20°C to 80°C, more preferably from 70°C to 80°C. The reaction is carried out for a duration of

[0048] 0.5 minutes to 30 minutes by continuously stirring the aqueous mixture in the slurry handling system. In addition to the in-situ formed silicate salt or disilicate salt of alkaline earth metal or mixtures thereof, the reaction may also produce hydroxide of alkaline earth metal and some amount of the alkaline earth metal salt may remain unreacted. Such that the aqueous mixture may include an amount of unreacted magnesium sulphate. After the reaction, the aqueous mixture includes the in-situ formed silicate salt or disilicate salt of alkaline earth metal or mixtures thereof, alkali metal silicate salt, detersive surfactant, any unreacted alkaline earth metal salt and water.

[0049] At this stage, after the reaction between the alkaline earth metal salt and the alkali metal silicate in presence of the detersive surfactant, the resulting aqueous mixture preferably includes:

[0050] (i) 0.1 wt.% to 4.5 wt.% in-situ formed silicate salt and / or disilicate salt of alkaline earth metal;

[0051] (ii) 8 wt.% to 30 wt.% alkali metal silicate salt; (iii) 11 wt.% to 40 wt.% detersive surfactant;

[0052] (iv) 50 wt.% to 60 wt.% water;

[0053] (v) optionally any unreacted alkaline earth metal salt.

[0054] Preferably the silicate salt or disilicate salt of the alkaline earth metal is 50% amorphous, more preferably 60% amorphous, still preferably 80%, further preferably 90% amorphous. In a highly preferred embodiment, all of the in-situ formed silicate salt and / or disilicate salt of alkaline earth metal salt is amorphous. Preferably the detersive surfactant is an anionic surfactant. In addition to this, the aqueous mixture may include hydroxide of alkaline earth metal and some amount of unreacted alkaline earth metal salt.

[0055] Preferably the aqueous mixture after forming the in-situ silicate salt of alkaline earth metal comprises: (i) 0.1 wt.% to 4.5 wt.% in-situ formed silicate salt and / or disilicate salt or of alkaline earth metal.

[0056] (ii) 8 wt.% to 30 wt.% alkali metal silicate salt.

[0057] (iii) 11 wt.% to 40 wt.% detersive surfactants; and, (iv) 50 wt.% to 60 wt.% water.

[0058] Step (iii): Adding a carbonate to the aqueous mixture to form an aqueous slurry

[0059] The next step involves adding sodium carbonate to form an aqueous slurry. In the process according to the first aspect, 10 wt.% to 62 wt.% of sodium carbonate and a filler selected from the group consisting of alkali metal chloride, alkaline earth metal carbonate or mixtures thereof is added to the aqueous mixture obtained in step (ii) followed preferably by addition of minor laundry ingredients, to form an aqueous slurry. Preferably the slurry may also include potassium carbonate. It is further preferred that sodium carbonate makes up at least 75 wt.%, more preferably at least 85 wt.% and even more preferably at least 90 wt.% of the total weight of the carbonate salt.

[0060] Preferably other non-carbonate builder may be included. Typically, inorganic builders include, crystalline and amorphous aluminosilicates for example, zeolites as disclosed in GB 1 473201 (Henkel), amorphous aluminosilicates as disclosed in GB 1 473202 (Henkel) and mixed crystalline / amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter & Gamble); sodium alkaline silicates and layered silicates as disclosed in EP 164514 B (Hoechst).

[0061] The sodium carbonate may be from synthetically prepared or from a natural source. Synthetically prepared soda ash is available commercially as synthetic light soda ash.

[0062] Inorganic phosphate builders for example sodium orthophosphate, pyrophosphate and tripolyphosphate are present at 0 wt.% level. The spray-dried detergent particle prepared from the process according to the first aspect of the present invention is substantially free of inorganic phosphate builders. By substantially free it is meant that the spray dried particle prepared according to the process of the first aspect does not include any deliberately added inorganic phosphate builder. The aqueous slurry includes 0 wt.% inorganic phosphate builders.

[0063] Zeolite builders used in most commercial particulate detergent compositions is zeolite A. Advantageously, aluminium zeolite P (zeolite MAP) described and claimed in EP 384070A (Unilever) may be used. Zeolite MAP is an alkali metal aluminosilicate of the P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 1.15, and more preferably not exceeding 1.07. Zeolite builders are preferably present at relatively low levels, for example less than 5 wt.%, still preferably less than 3 wt.%, further preferably less than 1 wt.% in the aqueous slurry. Most preferably the spray- dried detergent particle prepared from the process according to the first aspect of the present invention is substantially free of zeolite builders. By substantially free it is meant that the spray dried particle prepared according to the process of the first aspect does not include any deliberately added inorganic zeolite builder. Preferably the aqueous slurry includes 0 wt.% zeolite builders.

[0064] Optionally the aqueous slurry may include an organic builder. Non-limiting examples of organic builder include polycarboxylate polymers such as polyacrylates, acrylic / maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and trisuccinates, carboxy methyl oxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts. Preferably the organic builder is selected from monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates, more preferably alkali metal citrate, most preferably it is sodium citrate. Organic builders may be used in minor amounts as supplement to carbonate builder. Preferred supplementary organic builders are citrates, suitably used in amounts of from 0.1 wt.% to 30 wt.% more preferably of alkaline metal compounds, preferably from 10 wt.% to 25 wt.%; and acrylic polymers, more especially acrylic / maleic copolymers, suitably used in amounts of from 0.5 wt.% to 15 wt.%, preferably from 1 wt.% to 10 wt.%.

[0065] Powder flow properties may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate / maleate polymer. One preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 wt.% to 5 wt.%.

[0066] Further optional ingredients may be added to the aqueous slurry which includes but are not limited to, any one or more of the following: soap, sequestrants, calcium chloride, other inorganic salts, fluorescers, foam controllers, foam boosters, dyes, anti redeposition agents, colourants, shading dyes and combinations thereof.

[0067] A filler selected from the group consisting of alkali metal chloride, alkaline earth metal carbonate or mixtures thereof is added to the aqueous slurry before spray-drying. The filler may be added either before the addition of the sodium carbonate or after the addition of the sodium carbonate to the aqueous mixture to form the aqueous slurry. It is preferred to add the filler after the addition of the sodium carbonate. The filler acts as a balancing ingredient and is preferably selected from the group consisting of sodium chloride, calcium carbonate, magnesium carbonate, calcite, dolomite or mixtures thereof. In one preferred embodiment, the filler is alkali metal carbonate, more preferably sodium chloride. Alkaline earth metal carbonate preferably includes calcium carbonate (calcite), magnesium carbonate, magnesium calcium carbonate (dolomite) or mixtures thereof. The amount of alkali metal silicate remaining in the aqueous slurry after forming the in-situ silicate, disilicate of alkaline earth metal is from 3 wt.% to 14 wt.% of the aqueous slurry.

[0068] The aqueous slurry prepared according to the process of the first aspect of the present invention preferably comprises: (i) 5 wt.% to 30 wt.% detersive surfactant, preferably 5 wt.% to 27 wt.% detersive surfactant;

[0069] (ii) 10 wt.% to 62 wt.% sodium carbonate;

[0070] (iii) 3 wt.% to 14 wt.% alkali metal silicate;

[0071] (iv) 0.07 wt.% to 2 wt.% silicate salt and / or disilicate salt of alkaline earth metal; (v) 25 wt.% to 37 wt.% water;

[0072] (vi) from 0.08 wt.% to 51 wt.% filler selected from alkali metal chloride, alkaline earth metal carbonate or mixtures thereof, preferably a filler selected from sodium chloride, calcium carbonate, magnesium carbonate, calcite, dolomite, or mixtures thereof;

[0073] (vii) optionally, from 0 wt.% to 2 wt.% hydroxide salt of alkaline earth metal;

[0074] (viii) optionally, from 0 wt.% to 2 wt.% unreacted alkaline earth metal salt; (ix) optionally, from 0 wt.% to 3 wt.% polymer;

[0075] (x) optionally organic builder, preferably 0 wt.% to 10 wt.% citrate salt;

[0076] (xi) optionally optical brighteners which is preferably selected from fluorescers, colourants, shading dye, pigments or mixtures thereof;

[0077] (xii) optionally antifoams, preferably selected from silicone oil.

[0078] Preferably the detersive surfactant present in the aqueous slurry is an anionic surfactant. It may also be a mixture of anionic surfactant and nonionic surfactant where the mixture has a higher content of anionic surfactant. Preferably the polymer is selected from a cleaning polymer, soil releasing polymer, care polymer, antiredeposition polymer or mixtures thereof.

[0079] Step (iv): spray drying the aqueous slurry to form the spray-dried particle

[0080] In the next step, the aqueous slurry is spray dried to form a spray-dried particle. The spray-drying is carried out using any of the conventional spray drying system known in the art. Preferably in the spray drying system the aqueous slurry is transferred through a pipe system to a pump system consisting of one or more pump and then further to a spray nozzle through which the slurry is released under pressure into a drying tower.

[0081] A typical spray-drying process involves the step of transferring the aqueous slurry through a pipe system leading to a first pump and then through a second pump and from a second pump to a plurality of spray nozzles. The first pump is typically a low- pressure pump, such as a pump that can generate a pressure of from 1x105Nnr2to 1x106Nnr2, which ensures proper flooding of the second pump. Typically, the second pump is a high-pressure pump, such as a pump that is capable of generating a pressure ranging from 2x106Nnr2to 2x107Nnr2. Optionally, the aqueous detergent slurry may be transferred through bolt catchers, magnetic filters, lump breakers, disintegrators such as the Ritz Mill, during the transfer of the aqueous slurry through the pipe system downstream the pump system / mixer in which the aqueous slurry is formed. The disintegrator is preferably positioned between the pumps. The flow rate of the aqueous slurry along the pipes is typically in the range from 800 Kg / hour to more than 75,000 Kg / hour.

[0082] Optionally, the spray drying system may include a deaeration system. The deaeration system is preferably a vacuum assisted de-aerator, which is preferably fed by a transfer pump. The deaeration system remove air bubbles formed during the slurry preparation, thus increasing the bulk density of the spray-dried detergent particle. De aeration of the slurry may also be carried out by other mechanical means or chemical de-aeration means using antifoams or de-foamers.

[0083] Optionally, air injection system may be provided along the pipe system. The air injection system may be provided before or after the pump system. The air injection includes airflow and pressure controls, static mixer, pulsation dampener and compressor set which can aerate the slurry to get a lower bulk density for the spray dried particle. The gas injected into the slurry may be nitrogen, carbon dioxide, or simply atmospheric air introduced under a pressure higher than the pressure of the aqueous slurry maintained in the pipe system. A typical spray drying system can optionally include both the de-aeration system and air injection system to optimize the desired bulk density of the spray dried particle.

[0084] Typical spray drying tower for detergent applications are counter-current spray drying tower. To obtain the desired moisture content and the particle size distribution the inlet hot air / hot steam temperature introduced into the spray drying tower is the range from 250°C to 500°C depending on the evaporation capacity and sizing of the tower. Preferably the tower exhaust air temperature can range from, 60°C to 200°C, more preferably 80°C to 200°C, still more preferably 80°C to 100°C depending on the loading of the tower. The aqueous detergent slurry introduced into the spray nozzle of the spray drying tower is preferably at a temperature ranging from 60°C to 95°C. The spray drying tower may be a co-current spray drying tower but are less common. The spray- dried detergent particle existing the tower is maintained at a temperature less than 150°C, still preferably less than 100°C. The spray-drying is preferably conducted where the spray drying zone is under a negative pressure of at least 50 Nrrr2, still preferably the negative pressure is from 50 Nrrr2to 600 Nnr2. Preferably, the vacuum conditions are achieved by controlling the speed and / or dampener setting of the inlet and the outlet air fans.

[0085] The spray-dried particle collected at the bottom of the tower may be subjected to cooling and conditioning by using an air lift or any similar process. The spray-dried particle collected from the bottom of the spray-drying tower is preferably mixed with a flow aid chosen from zeolite or similar fine mineral particles selected from dolomite, calcite or mixtures thereof, just before being air-lifted. Preferably, the spray-dried detergent is subject to particle size classification to remove oversize material (> 2 mm typically) to provide a spray dried detergent particle which is free flowing. Preferably the fine material (< 100 microns typically) is elutriated with the exhaust air in the spray drying tower and captured and recycled back into the system via the dry cyclone, wet cyclone or bag filter system.

[0086] Spray-dried detergent particle:

[0087] According to an aspect of the present invention disclosed is a spray-dried particle obtainable by the process of the first aspect. Spray-dried particle formed from the process of the first aspect of the present invention preferably has a pH of 11.5 or less, preferably a pH ranging from 10.5 to 11.5 when measured using a 1 wt.% solution with distilled water at 25°C. The spray-dried particle is generally referred to as the base powder. This base powder may be used as a fully formulated laundry detergent composition.

[0088] Preferably the spray-dried detergent particle includes:

[0089] (i) 7 wt.% to 40 wt.% detersive surfactant; preferably anionic detersive surfactant;

[0090] (ii) 15 wt.% to 81 wt.% carbonate salt; (iii) 5 wt.% to 17 wt.% alkali metal silicate;

[0091] (iv) 0.1 wt.% to 2.5 wt.% in-situ formed silicate salt and / or disilicate salt of alkaline earth metal; (v) from 1 wt.% to 70 wt.% filler selected from alkali metal chloride, alkaline earth metal carbonate, preferably the filler is selected from sodium chloride, calcium carbonate, magnesium carbonate, calcite, dolomite or mixtures thereof;

[0092] (vi) preferably 0.1 wt.% to 4.5 wt.% water;

[0093] (vii) optionally, from 0 wt.% to 4 wt.% polymer;

[0094] (viii) optionally organic builder, preferably 0 wt.% to 10 wt.% citrate salt

[0095] (ix) optionally from 0 wt.% to 2.5 wt.% hydroxide salt of alkaline earth metal; and,

[0096] (x) optionally, from 0 wt.% to 2.5 wt.% unreacted alkaline earth metal salt. It is preferred to keep the moisture content of the spray-dried detergent particle not more than 4.5 wt.% to ensure that the spray-dried particle is free-flowing. Preferably the amount of filler present is 1 wt.% to 67 wt.%.

[0097] In one embodiment the spray-dried detergent particle may include 0 wt.% added sodium sulphate, the spray dried detergent particle may however include in-situ formed sodium sulphate in an amount which is less than 4 wt.%, still preferably less than 1.5 wt.%

[0098] The spray dried detergent particle may preferably include from 0 wt.% to 4 wt.% polymer selected from antiredeposition polymer, soil release polymer, structuring polymer or mixtures thereof. Preferably the polymer is a polymeric carboxylate, preferably polyacrylate or a copolymer of acrylic acid and maleic acid. However other polymers may also be suitable such as polyamines (including the ethoxylated variants thereof), polyethylene glycol and polyesters. Polymeric soil suspending aids and polymeric soil release agents are particularly suitable.

[0099] Preferably the spray-dried detergent particle has a bulk density of less than 550g / L. Preferably the spray-dried detergent particle has a weight average particle size of from 300 micrometres to 600 micrometres.

[0100] The spray-dried detergent particle comprises from 7 wt.% to 40 wt.% anionic surfactants, which is preferably a Cio to C20linear alkyl benzene sulphonate and which is substantially neutralized with little or no acid residues. The spray-dried particle is typically post dosed with ingredients that are incompatible with the spray-drying process conditions to form a fully formulated laundry detergent composition. These components may be incompatible for many reasons including heat sensitivity, pH sensitivity or degradation in aqueous systems.

[0101] Laundry detergent composition

[0102] Detergent compositions of low to moderate bulk density may be prepared by spray drying the aqueous slurry to form a spray-dried particle and optionally postdosing (dry mixing) further ingredients. Alternately "compact" detergent compositions may be prepared by further mixing the spray dried particle prepared according to the present invention in a high-speed mixer / granulator, or other non-tower processes. The spray dried detergent particle may also be used for preparing a tablet composition by compacting powders, especially "concentrated" powders using the known tableting process. Further, the spray dried detergent particle may be used for preparing an unit dose product where the spray-dried detergent particle is enclosed in a pouch, preferably a water-soluble pouch, more preferably a water-soluble pouch comprising a film forming polymer selected from polyvinyl alcohol, polyvinylpyrrolidone and other known film forming polymer. The base powder / spray-dried particle is preferably formulated into a finished detergent composition by dry mixing heat sensitive ingredients into the base powder. In addition to heat sensitive ingredients some amount of alkalinity may be added back into the base powder by addition of alkaline ingredients, additionally other acidic or neutral may also be added to formulate the finished detergent composition.

[0103] The spray-dried detergent particle may be used as a fully formulated laundry detergent composition or may be additionally combined with other optional ingredients to form a fully formulated laundry detergent composition. Non-limiting examples of the optional post-dosed benefit ingredients includes but is not limited to enzymes, anti-redeposition polymers, perfumes, additional surfactant selected from amphoteric surfactant, zwitterionic surfactant, cationic surfactant and non-ionic surfactant, optical brighteners, antifoaming agent, foam boosters, fabric softeners such as smectite clays, amine softeners and cationic softeners; bleach and bleach activators; dyes or pigments, fillers, fluorescers, salts, soil release polymers, dye transfer inhibitors. These optional ingredients are well known to be used in a laundry detergent composition and added preferably by post-dosing. Non-limiting examples of the post-dosed polymers include cleaning polymers, antiredeposition polymers, soil release polymers structuring polymers. Some examples include PET-PEOT polymer (Repel-o-Tex® SF2 ex.Solvay), copolymer of acrylic acid and maleic acid (Sokalan CP5 ex. BASF). Fluorescers

[0104] Suitable fluorescent brighteners include dis-styryl biphenyl compounds example Tinopal® CBS-X, di-amino stilbene di-sulfonic acid compounds, e.g. Tinopal® DMS pure Xtra and Blankophor® HRH, and Pyrazoline compounds, e.g. Blankophor® SN, and coumarin compounds, e.g. Tinopal® SWN. Preferred brighteners are: sodium 2 (4- styry)-3-sulfophenyl)-2H-napthol(1,2-d]triazole, disodium 4,4’bis{[4-anilino-6-(N methyl- N-2 hydroxyethyl)amino 1,3,5- triazin-2-yl)]amino]stilbene-2-2' disulfonate, disodium 4,4’bis([(4-anilino-6-morpholino-l,3,5-triazin-2-yl)]amino} stilbene-2-2'disulfonate, and disodium 4,4’- bis(2-sulfostyryl)biphenyl. A suitable fluorescent brightener is S C.l. Fluorescent Brightener 260, which may be used in its beta or alpha crystalline forms, or a mixture of these forms.

[0105] Enzymes:

[0106] The composition of the present invention preferably includes an enzyme. It may preferably include one or more enzymes. Preferred examples of the enzymes include those which provide cleaning performance and / or fabric care benefits.

[0107] Examples of suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, xyloglucanase, phospholipases, esterases, cutinases, pectinases, mannanases, pectate lyases, keratinases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, G-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof. A typical combination is an enzyme cocktail that may comprise, for example, a protease and lipase in conjunction with one or more of amylase, mannanase and cellulase. When present in a detergent composition, the enzymes may be present at levels from about 0.00001% to about 2%, from about 0.0001% to about 1% or from 0.001% to about 0.5% enzyme protein by weight of the detergent composition.

[0108] Packaging and dosing

[0109] The spray dried detergent particle or a laundry composition having the spray dried detergent particle prepared according to the invention may be packaged as unit doses in polymeric film soluble in the wash water. Alternatively, the spray-dried detergent particle or a composition including the particle of the invention may be supplied in multidose plastics packs with a top or bottom closure. A dosing measure may be supplied with the pack either as a part of the cap or as an integrated system. The packaging material suitable for packaging may include but not limited to multilayer polyethylene film, laminate, paper based, and other materials known to a person skilled in the art. Preferably the packaging material is selected from material which are biodegradable or recyclable.

[0110] According to another aspect of the present invention, provided is a method of laundering fabric using a spray dried detergent particle or a laundry composition comprising a spray dried detergent particle according to the present invention which involves the step of diluting the dose of detergent composition with water to obtain a wash liquor and washing fabrics with the wash liquor so formed. In automatic washing machines the dose of detergent composition is typically put into a dispenser and from there it is flushed into the machine by the water flowing into the machine, thereby forming the wash liquor. From 5 up to about 65 litres of water may be used to form the wash liquor depending on the machine configuration. The dose of detergent composition may be adjusted accordingly to give appropriate wash liquor concentrations. The dilution step preferably provides a wash liquor which comprises inter alia from about 3 to about 20 g / wash of detersive surfactants (as are further defined above). Examples

[0111] Example 1: Preparing an aqueous slurry and a spray dried detergent particle according to the present invention

[0112] A spray-dried laundry detergent particle according to the present invention was prepared by first mixing water, neutralizing agent (NaOH, 50% aqueous solution) and linear alkyl benzene sulphonic acid in a crutcher where they were agitated to neutralize the linear alkyl benzene sulphonic acid to its salt form. Thereafter an excess of sodium silicate (47% aqueous solution, alkali metal silicate) was added to the aqueous mixture. The sodium silicate has a Na20 to S1O2 ratio of 1:2.4. The addition of sodium silicate was followed by addition of magnesium sulphate (alkaline earth metal salt). The aqueous mixture was continuously agitated, and the mixture was heated to a temperature of around 78°C to 80°C upon addition of sodium silicate and the temperature was maintained till the end of the batch preparation. The sodium silicate and magnesium sulphate react to form in-situ magnesium silicate or magnesium disilicate or combination of bothr Further sodium carbonate and sodium chloride as filler, was added in this order to form an aqueous slurry. The composition of the ingredients added to the form a batch of 10000 Kg aqueous slurry is provided in Table 1. A. Preparing the aqueous slurry:

[0113] Table 1

[0114] B. Preparing the spray-dried detergent particle:

[0115] The aqueous slurry of Example 1 was spray dried to prepare a spray dried detergent particle which was thereafter evaluated.

[0116] The aqueous slurry was spray-dried in a conventional counter current spray drying tower to form a spray dried detergent particle with a moisture content of around 2 wt.% to 3.5 wt.%. The composition of the spray dried powder is provided in Table 2 below. Table 2

[0117] The spray-dried detergent particle prepared according to the present invention (Ex 1) was evaluated for powder properties as described below. Compression test This test evaluates the tendency of the powder towards caking. A split cylinder with a polished internal surface is positioned on a firm base to form a hollow cylindrical mould with a diameter of 9 centimetres. Spray dried detergent particle prepared according to the present invention (Ex 1) was filled inside the hollow cylindrical mould and levelled. A plastic disc is placed on levelled spray-dried detergent particle mass. A weight of 12 kilogram is slowly placed on the plastic disc in such a way that the weight is uniformly applied on the spray-dried detergent particle mass in the mould and the disc was allowed to compact the spray-dried detergent particle mass to form a compacted cake. After 2 minutes the weight was removed, and the cylindrical mould is opened slowly without disturbing the compacted cake mass. Next, incremental weights of 200 grams is added at an interval of 10 seconds till the compacted cake mass collapses. Total vertical load required to collapse the compacted cake mass is noted and expressed in grams and this amount in grams is indirectly defined as the caking tendency. Higher the value of the vertical load required to collapse the compacted cake mass the greater is the caking tendency of the powder under evaluation. For the present evaluation, values lower than 1 Kilogram is considered good and values beyond 2 Kilogram is classified as cohesive and classified as powder with high caking tendency. Similarly, the compression test was conducted on the spray- dried particle, Comp A.

[0118] Dynamic flow rate (DFR) measurement: The apparatus used for measuring DFR consists of a cylindrical glass tube having an internal diameter of 35 mm and a length of 600 mm. The tube was securely clamped in a position such that its longitudinal axis is vertical. Its lower end was terminated by means of a smooth cone of polyvinyl chloride having an internal angle of 15 and a lower outlet orifice of diameter 225 mm. A first beam sensor is positioned 150 mm above the outlet, and a second beam sensor is positioned 250 mm above the first sensor. To determine the dynamic flow rate of a powder sample, the outlet orifice was temporarily closed, for example, by covering with a piece of card, and powder is poured through a funnel into the top of the cylinder until the powder level is about 10 cm higher than the upper sensor; a spacer between the funnel and the tube ensures that filling is uniform. The outlet is then opened and the time t (seconds) taken for the powder level to fall from the upper sensor to the lower sensor was measured electronically. The measurement was normally repeated two or three times and an average value taken. If V was the volume (ml) of the tube between the upper and lower sensors, the dynamic flow rate DFR (ml / s) was given by the following equation: DFR= V / 1. The averaging and calculation are carried out electronically and a direct read-out of the DFR value obtained. A DFR value of higher than 80 mL / s is considered to have good flow properties.

[0119] Results: The compression test was conducted for the spray-dried detergent particle according to the invention (Ex 1) and also for the comparative particle (Comp A) with no formed in-situ magnesium silicate and which included sodium sulphate as the filler.

[0120] It was found that the spray-dried detergent particle of Ex 1 showed lower value during the compression test, suggesting that the composition according to the present invention has good powder properties and comparatively better and prolonged storage life.

[0121] Example 2: Preparing an aqueous slurry and a spray dried detergent particle according to the present invention A spray-dried laundry detergent particle according to the present invention was prepared by first mixing water, neutralizing agent (NaOH, 48% aqueous solution) and linear alkyl benzene sulphonic acid in a crutcher where they were agitated to neutralize the linear alkyl benzene sulphonic acid to its salt form. Thereafter an excess of sodium silicate (42% aqueous solution, alkali metal silicate) was added to the aqueous mixture. The sodium silicate has a Na20 to S1O2 ratio of 1:2.4. The addition of sodium silicate was followed by addition of magnesium sulphate (alkaline earth metal salt). The aqueous mixture was continuously agitated, and the mixture was heated to a temperature of around 78°C to 80°C upon addition of sodium silicate and the temperature was maintained till the end of the batch preparation. The sodium silicate and magnesium sulphate react to form in-situ magnesium silicate or magnesium disilicate or combination of bothr Further sodium carbonate and sodium chloride as filler, was added in this order to form an aqueous slurry. The ingredients added to the form a batch of 4800 Kg aqueous slurry is provided in Table 3. A. Preparing an aqueous slurry

[0122] Table 3

[0123] B. Preparing the spray-dried detergent particle:

[0124] The aqueous slurry of Exp 2 was spray dried to prepare a spray dried detergent particle which was thereafter evaluated.

[0125] The aqueous slurry was spray-dried in a conventional counter current spray drying tower to form a spray dried detergent particle with a moisture content of around 2 wt.% to 3.5 wt.%. The composition of the spray dried powder is provided in Table 4 below. Table 4

[0126] The data on table 4 shows that the inventive spray dried detergent particle (Ex 2) showed similar powder properties as that of the Control. The inventive spray-dried particle was free-flowing as shown by the DFR values (above 80 mL / s) and showed anticaking properties over extended storage life as show by the compression test values (less than 1Kg).

Claims

DEPCT671. A process for the preparation of spray-dried detergent particles, such process consisting of the following steps: (i) contact of alkaline earth metal salts with alkali silicate metal salts in an aqueous mixture containing detergent surfactants, where the alkaline earth metal salts react with the alkali silicate metal salts to form alkaline earth metal silicate and / or disilicate salts therein; (ii) addition of sodium carbonate and fillers selected from the group containing alkali chloride, alkaline earth metal carbonate, or a mixture of such things to form a slurry aquias; in which the slurry aquias contains alkali silicate metals, silicate salts and / or disilicate salts of alkaline earth metals formed therein, sodium carbonate salts 10% by weight to 62% by weight, fillers, phosphate builder 0% by weight, and detergent surfactants; (iii) spray drying of such slurry aquias to form such spray-dried detergent particles; 2. The process according to claim 1 in which the slurry aquias contains zeolite builder 0% by weight; 3.

1. A process under Reputation 1 in which alkali silicate metals are present in a stoichiometric excess of the amount required for reaction with alkaline earth metal salts.

4. Any one of the processes under Reputations 1 through 3 in which alkaline earth metal salts are chosen from calcium sulfate, calcium chloride, magnesium sulfate, magnesium chloride, or a combination thereof, with magnesium sulfate being preferred.

5. Any one of the processes under the preceding Reputation in which the alkali silicate metal is sodium silicate.

6. Any one of the processes under the preceding Reputation in which the silicate or disilicate salts of alkaline earth metals formed therein are at least 50% amorphous.

7. Any one of the processes under the preceding Reputation in which the weight ratio of alkali silicate metal to alkaline earth metal salts added to the aqueous mixture is in the range from 260:1 to 5:1, with 24:1 to 7:1 being preferred. 8.A process under one of the preceding claims in which the alkaline earth carbonate metal filler is selected from a group consisting of calcium carbonate (calcite), magnesium carbonate, calcium magnesium carbonate (dolomite), or a mixture of such, and the alkali metal chloride is sodium chloride.

9. A process under one of the preceding claims in which the detergent surfactant is an anionic surfactant, suitable for selection from a group consisting of alkylbenzene sulfonate, alkoxylated alkyl sulfate, alkyl sulfate, alkyl ether sulfate, 10. A process under claim 9 in which an anionic surfactant is selected from a salt of a completely neutralized anionic surfactant, a partially neutralized anionic surfactant, or an acidic form of a completely neutralized anionic surfactant in the form of a salt therein.

11. A process under any of the preceding claims in which the spray-dried detergent particles have a weight ratio of sodium carbonate to detergent surfactant less than 112.The process under any prior claim, in which the slurry equator consists of: (i) 5% by weight to 30% by weight of detergent surfactant; (ii) 0.07% by weight to 2% by weight of alkaline earth metal silicate and / or disilicate salts; (iii) 10% by weight to 62% by weight of sodium carbonate; (iv) 3% by weight to 14% by weight of alkali silicate metals; (v) 20% by weight to 40% by weight of water; (vi) an additive of choice of alkali metal chlorides, alkaline earth metal carbonates or mixtures of such from 0.07% by weight to 2% by weight;(vii) Optionally, alkaline earth metal hydroxide salts from 0% by weight to 2% by weight; (viii) Optionally, nonreactive alkaline earth metal salts from 0% by weight to 2% by weight; (ix) Optionally, polymers from 0% by weight to 3% by weight; (x) Optionally, organic builders, suitable citrate salts from 0% by weight to 10% by weight; (xi) Optionally, optical illuminators, of which suitability is chosen. From fluorescent agents, colorants, shaping dyes, pigments; and, (xii) alternatively, suitable antifoaming agents selected from silicone oils.

13. Spray-dried detergent particles obtainable by any of the preceding patent processes, in which the spray-dried detergent particles consist of: (i) detergent surfactants 7% by weight to 40% by weight; (ii) silicate and / or disilicate salts of alkaline earth metal salts formed therein 0.1% by weight to 2.(iii) sodium carbonate 15% by weight to 81% by weight; (iv) alkali metal silicate salts 5% by weight to 17% by weight; (v) filler of choice of alkali metal chloride, alkaline earth metal carbonate or mixtures of such from 1% by weight to 70% by weight; (vi) suitable water from 0.1% by weight to 4.5% by weight; (vii) optional, polymer from 0% by weight to 4% by weight; (viii) optional, alkaline earth metal hydroxides 0% by weight to 2.5% by weight; (ix) optional, alkali metal salts 14. Detergent compositions for washing containing from 5% by weight to 95% by weight of spray-dried detergent particles according to any of the preceding claims. 15.Detergent compositions for washing as claimed in claim 14, in which the composition contains one or more washing ingredients selected from a group of enzymes, sequestrants, foaming agents, antifoaming agents, fragrances, dyes, coloring agents, visible markers or mixtures of such;