AU608972B2 - Liquid cleaning products - Google Patents

Description

111~~11111---- 11111 111~ 111~ om~i r

AUSTRALIA

Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: .4 TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: UNILEVER PLC UNILEVER HOUSE

BLACKFRIARS

LONDON EC4

ENGLAND

Actual Inventor: Address for Service: GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Complete Specification for the invention entitled: LIQUID CLEANING PRODUCTS.

The following statement is a full description of this invention including the best method of performing it known to me:- 14 C.3239 alkali-metal salt forms. Mixtures of these may also be used.

Examples of uhosohoriiq-rnn+r-n4,,,,'

I

4- 11- C.3239 LIQUID CLEANING PRODUCTS The present invention is concerned with substantially non-aqueous liquid cleaning products of the kind 5 comprising particles of aluminosilicate builder disperse- In a liquid phase.

o o Aluminosilicates are a class of builder very well known in the detergents industry. Their incorporation in non-aqueous dispersions can otten result in profound gassing, perhaps caused by evolution of gas trapped in the pores of the aluminosilicate and/or catalytic decomposition of other components.

The applicants have now found that this rroblem can be substantially mitigated if the composition also contains a specific strongly alkaline material. However, the composition must then be substantially free of bleach precursor which would thus be rendered unstable, unless such a precursor is physically separate from the liquid, eg. by being encapsulated in a material insoluble in the liquid phase of the product but soluble or dispersible in water.

i 2 C.3239 Thus, according to the invention there is provided a substantially non-aqueous liquid cleaning product composition comprising solid particles of aluminosilicate builder dispersed in a liquid phase, said composition also comprising a an alkalimetal metasilicate and being substantially free of bleach precursor.

Bleach precursors are conventional materials used to aid low temperature bleaching in combination with inorganic persalt compounds.

The exact mode of action of such precursors is not known, but it is believed that peracids are formed by Sreaction of the precursors with the inorganic peroxy 15 compound, which peracids then liberate active-oxygen by decomposition.

0 0 0 They are generally compounds which contain N-acyl or O-acyl residues in the molecule and which exert their activating action on the peroxy compounds on contact with these in the washing liquor.

a0 a* 0 The strongly alkaline material is selected from alkali metal, especially sodium, metasilicate, and mixtures thereof with other alkaline materials such as sodium hydroxide and potassium hydroxide. Normally, they will be incorporated at from 1% to 10%, typically around 5% by weight of the total composition.

UK Patent specification GB-A-2 194 546 (Colgate-Palmolive) describes non-aqueous dispersions of particulate solids for dishwashing. Compositions exemplified therein optionally contain sodium metasilicate in an amount of from 5% to 18% by weight of the total composition. The disclosure envisages use of aluminosilicates in the dishwashing products, but a I I I I 3 C.3239 specific combination of sodium metasilicate with an aluminosilicate builder is not disclosed. Moreover, those compositions all contain a bleach precursor (TAED) which would be incompatible with the compositions of the present invention. Thus, GB-A-2 194 546 does not hint at the problem addressed by the present invention, nor is its solution suggested.

European Patent Specification EP 28849-A (Unilever) describes non-aqueous built liquid detergent compositions which contain the combination of a specific copolymer and a strongly alkaline material, among examples of which are sodium carbonate, sodium hydroxide and sodium disilicate.

The use of sodium metasilicate is not proposed. The 15 liquids may optionally contain bleaches, with or without S0.. °bleach precursors. Specified builders include sodium o o tripolyphosphate and zeolites. There is however no S00 mention of the problem to which the present invention relates, nor is a solution thereof suggested.

In the compositions of the present invention, the aluminosilicate builder may be selected from crystalline or amorphous materials, for example having the general formula: c400 Naz (AlO 2 )z (Si 2 )y x H 2 0 Swherein Z and Y are integers of at least 6, the molar Sratio of Z to Y is in the range from 1.0 to 0.5, and x is an integer from 6 to 189 such that the moisture content is from about 4% to about 20% by weight (termed herein, 'partially hydrated'). This water content provides the best rheological properties in the liquid. Above this level up to about 28% by weight water content), the water level can lead to network formation. In conventional dispersions, below this level from 0 to

I

4 C.3239 about 6% by weight water content), trapped gas in pores of the material can be displaced, which causes gassing and tends to lead to a viscosity increase also. Gassing is also caused by decomposition of the perborate, probably catalysed by the zeolite. However, this is inhibited by use of the metasilicate in accordance with the present invention. Also, the anhydrous materials with 0 to about 6% by weight of water) can be used as structurants.

The preferred range of aluminosilicate is from about 12% to about 30% on an anhydrous basis. The aluminosilicate preferably has a particle size of from 0.1 to 100 microns, ideally betweeen 0.1 and 10 microns.

0 0° °In the compositions of the present invention, the i 15 liquid phase can be a liquid surfactant, an organic °0o non-aqueous non-surfactant liquid, or a mixture of such °0 materials. Many of the compositions do contain a surfactant as a dispersed or dissolved solid, or more So 0 often, as all or part of said liquid phase. These surfactant compositions are liquid detergent products, S e.g. for fabrics washing or hard surface cleaning.

o°o°"o However, the wider term 'liquid cleaniing product' also includes non-surfactant liquids which are still useful in clearing, for example non-aqueous bleach products or those in which the liquid phase consists of one or more light, non-surfactant solvents for greasy stain pre-treatment of j f±abrics prior to washing. Such pre-treatment products can contain solid bleaches, dispersed enzymes and the like.

The solid particles can be maintained in dispersion in the liquid phase resist settling, even if not perfectly) by a number of means. For example, settling may be inhibited purely by virtue of the relative small size of the particles and the relatively high viscosity of the solvent phase. In other words, the particles settle very slowly at a rate predicted by Stokes' law or due to -I r r i- 5 C.3239 the formation ot a loosely aggregated network of particle flocs. This effect is utilised in the compositions described in patent specifications EP-A-30 096 and GB 2 158 838A. However, there have also been several prior proposals to utilise additional means to enhance solid-suspending properties in such non-aqueous liquids.

These are somewhat analogous to so-called external structuring techniques used in aqueous systems; in addition to the particulate solids and the liquid phase in which they are to be suspended, an additional dispersant Is used which by one means or another, acts to aid stable dispersion or suspension of the solids for a finite o period. Any of these means may be employed in the compositions according to the present invention.

"0 One such suitable stabilisation involves use of f'l° nonionic surfactant as the solvent and to add an inorganic ,0 carrier material as the dispersant, in particular highly voluminous silica. This acts by forming a solid-suspending network. This silica is highly voluminous by virtue of having an extremely small particle size, hence high surface area. This is described in GB patent specifications 1,205,711 (Unilever) and 1,270,040 (Unilever). However, there can be a problem with these compositions of setting upon prolonged storage.

A similar suitable structuring can be effected using fine particulate chain structure-type clay, as described in specification EP-A-34,387 (Procter Gamble).

Another appropriate known use of a substance as a dispersant for particles in nonionic-based non-aqueous compositions entails incorporating a hydrolyzable co-polymer of maleic anhydride with ethylene or vinylmethylether, which co-polymer is at least hydrolyzed. This is described in specification 6 C.3239 EP-A-28,849 (Unilever). However, a problem with these compositions can be the difficulty in controlling manufacture to obtain reproducible product stability.

Another appropriate means by which such dispersions have been stabilised is the use of a dispersant material which has been termed 'a deflocculant', according to the disclosure of European Patent Specification EP-A-266 199 (Unilever). Particularly preferred deflocculants are alkyl (especially dodecyl) benzene sulphonic acids (as the free acid) and lecithin.

All compositions according to the present invention are liquid cleaning products. They may be formulated in a 15 very wide range of specific forms, according to the intended use. They may be formulated as cleaners for hard o "o surfaces (with or without abrasive) or as agents for warewashing (cleaning of dishes, cutlery etc) either by hand or mechanical means, as well as in the torm of specialised cleaning products, such as for surgical S, apparatus or artificial dentures. They may also be o 'formulated as agents for washing and/or conditioning of fabrics.

In the case of hard-surface cleaning, the compositions may be formulated as main cleaning agents, or pre-treatment products to be sprayed or wiped on prior to removal, e.g. by wiping off or as part of a main cleaning operation.

In the case of warewashing, the compositions may also be the main cleaning agent or a pre-treatment product, e.g applied by spray or used for soaking utensils in an aqueous solution and/or suspension thereot.

7 C.3239 Those products which are formulated for the cleaning and/or conditioning of fabrics constitute an especially preferred form of the present invention. These compositions may for example, be of the kind used for pre-treatment of fabrics for spot stain removal) with the composition neat or diluted, before they are rinsed and/or subjected to a main wash. The compositions may also be formulated as main wash products, being dissolved and/or dispersed in the water with which the I 10 fabrics are contacted. In that case, the composition may be the sole cleaning agent or an adjunct to another wash product. Within the context of the present invention, the term 'cleaning product' also embraces compositions of the S€ kind used as fabric conditioners (including fabric ,j 0 15 softeners) which are only added in the rinse water *P (sometimes referred to as 'rinse conditioners') Thus, the compositions will contain at least one agent which promotes the cleaning and/or conditioning of the article(s) in question, selected according to the intended application. Usually, this agent will be 0K0 selected from surfactants, enzymes, bleaches, 9 90 microbiocides, (for fabrics) fabric softening agents and 4440 (in the case of hard surface cleaning) abrasives, Of course in many cases, more than one of these agents will be present, as well as other ingredients commonly used in the relevant product form.

.4 4 CL The compositions will be substantially free from agents which are detrimental to the article(s) to be treated. For example, they will be substantially free trom pigments or dyes, although of course they may contain small amounts of those dyes (colourants) of the kind often used to impart a pleasing colour to liquid cleaning i products, as well as fluorescers, bluing agents and the like.

7 I I I I 8 C.3239 All ingredients before incorporation will either be liquid, in which case, in the composition they will constitute all or part of the liquid phase, or they will be solids, in which case, in the composition they will either be dispersed as deflocculated particles in the liquid phase or they will be dissolved in the liquid phase. Thus as used herein, the term "solids" is to be construed as referring to materials in the solid phase which are added to the composition and are dispersed therein in solid form, those solids which dissolve in the liquid phase and those in the liquid phase which solidify (undergo a phase change) in the composition, wherein they are then dispersed.

15 If a deflocculant is incorporated, some liquids are alone, unlikely to be suitable to perform the function of liquid phase for any combination of solids and dispersant/deflocculant. However, they will be able to be incorporated it used with another liquid which does have the required properties, the only requirement being that where the liquid phase comprises two or more liquids, they are miscible when in the total composition or one can be dispersible in the other, in the form of fine droplets.

i a~ 0 I 0 0 0 o Q o 0 00 Sa i a 0 00 0o0 o0 o o4 0 0 o o o o o o 0 0 0 o o o 0 0 1 a 0 0 e Thus, where surfactants are solids, they will usually be dissolved or dispersed in the liquid phase. Where they are liquids, they will usually constitute all or part of the liquid phase. Also, some surfactants are eminently suitable as deflocculants.

ci cc I c 1 Ic In general however, surfactants may be chosen from any of the classes, sub-classes and specific materials described in 'Surface Active Agents' Vol. I, by Schwartz Perry, Interscience 1949 and 'Surface Active Agents' Vol.

II by Schwartz, Perry Berch (Interscience 1958), in the current edition of "McCutcheon's Emulsifiers Detergents" 9 C.3239 published by the McCutcheon division of Manufacturing Confectioners Company or in 'Tensid-Taschenbuch', H.

Stache, 2nd Edn., Carl Hanser Verlag, Mfnchen Wien, 1981.

Liquid surfactants are an especially preferred class of material to use in the liquid phase, especially polyalkoxylated types and in particular polyalkoxylated nonionic surfactants.

As a general rule, the applicants have tound that the most suitable liquids to choose as the liquid phase are organic materials having polar molecules. In particular, those comprising a relatively lipophilic part and a 00 0 o 15 relatively hydrophilic part, especially a hydrophilic part rich in electron lone pairs, tend to be well suited. This is completely in accordance with the observation that liquid surfactants, especially polyalkoxylated nonionics, .o are one preferred class of liquid.

o Nonionic detergent surfactants are well-known in the art. They normally consist of a water-solubilizing o, polyalkoxylene or a mono- or di-alkanolamide group in .chemical combination with an organic hydrophobic group 25 derived, for example, from alkylphenols in which the alkyl 0 group contains from about 6 to about 12 carbon atoms, dialkylphenols in which each alkyl group contains from 6 to 12 carbon atoms, primary, secondary or tertiary aliphatic alcohols (or alkyl-capped derivatives thereof), preterably having from 8 to 20 carbon atoms, monocarboxylic acids having from 10 to about 24 carbon atoms in the alkyl group and polyoxypropylenes. Also common are fatty acid mono- and dialkanolamides in which the alkyl group of the fatty acid radical contains from to about 20 carbon atoms and the alkyloyl group having trom 1 to 3 carbon atoms. In any of the mono- and di- 10 C.3239 alkanolamide derivatives, optionally, there may be a polyoxyalkylene moiety joining the latter groups and the hydrophobic part of the molecule. In all polyalkoxylene containing surfactants, the polyalkoxylene moiety preterably consists of from 2 to 20 groups of ethylene oxide or of ethylene oxide and propylene oxide groups.

Amongst the latter class, particularly preferred are those described in European specification EP-A-225,654 (Unilever), especially for use as all or part of the solvent. Also preferred are those ethoxylated nonionics which are the condensation products of fatty alcohols with from 9 to 15 carbon atoms condensed with from 3 to 11 moles of ethylene oxide. Examples of these are the ,condensation products of C 11 13 alcohols with (say) 3 or 7 S611-13 I 15 moles ot ethylene oxide. These may be used as the sole nonionic surtactants or in combination with those of the described in the last-mentioned European specification, especially as all or part of the liquid phase.

o 0 0 o o0 Another class of suitable nonionics comprise the alkyl polysaccharides (polyglycosldes/oligosaccharides) •ao such as described in any of specifications US 3,640,998; I o aUS 3,346,558; US 4,223,129; EP-A-92,355; EP-A-99,183; EP-A-70,074, '75, '76, '77; EP-A-75,994, '95, '96.

Nonionic detergent surfactants normally have molecular weights of from about 300 to about 11,000.

Mixtures of difterent nonionic detergent surfactants may also be used, provided the mixture is liquid at room temperature. Mixtures of nonionic detergent surfactants with other detergent surfactants such as anionic, cationic or ampholytic detergent surfactants and soaps may also be used. If such mixtures are used, the mixture must be liquid at room temperature.

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I 11 C.3239 Examples of suitable anionic detergent surfactants are alkali metal, ammonium or alkylolamaine salts of alkylbenzene sulphonates having from 10 to 18 carbon atoms in the alkyl group, alkyl and alkylether sulphates having trom 10 to 24 carbon atoms in the alkyl group, the alkylether sulphates having from 1 to 5 ethylene oxide groups, olefin sulphonates prepared by sulphonation of

C

10

-C

24 alpha-olefins and subsequent neutralization and hydrolysis of the sulphonation reaction product.

Other surfactants which may be used include alkali metal soaps of a fatty acid, preferably one containing 12 to 18 carbon atoms. Typical such acids are oleic acid, 1 ricinoleic acid and fatty acids derived from caster oil, O0 0 S 15 rapeseed oil, groundnut oil, coconut oil, palmkernal oil or mixtures thereof. The sodium or potassium soaps of .44 these acids can be used. As well as fulfilling the role S0O ot surfactants, soaps can act as detergency builders or 0o fabric conditioners, other examples of which will be described in more detail hereinbelow. It can also be remarked that the oils mentioned in this paragraph may o o o themselves constitute all or part of the liquid phase, 0 o0 whilst the corresponding low molecular weight fatty acids (triglycerides) can be dispersed as solids or function as structurants.

Yet again, it is also possible to utilise cationic, zwitterionic and amphoteric surfactants such as referred to in the general surfactant texts referred to hereinbefore. Examples of cationic detergent surfactants are aliphatic or aromatic alkyl-di(alkyl) ammonium halides and examples of soaps are the alkali metal salts of

C

12

-C

24 fatty acids. Ampholytic detergent surfactants are e.g. the sulphobetaines. Combinations of surfactants from within the same, or from different classes may be employed DI-rr~-rmn~-~CIWCn~"~ 12 C.3239 to advantage for optimising structuring and/or cleaning performance.

Non-surfactants which are suitable as solvents include those having the preferred molecular forms referred to above although other kinds may be used, especially if combined with those of the former, more

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o 00 0 0 o0 o D o o o preferred types. In general, the non-surfactant solvents can be used alone or with in combination with liquid surfactants. Non-surfactant solvents which have molecular structures which fall into the former, more preferred category include ethers, polyethers, alkylamines and fatty amines, (especially di- and tri-alkyl- and/or fatty- Nsubstituted amines), alkyl (or fatty) amides and mono- and di- N-alkyl substituted derivatives thereof, alkyl (or fatty) carboxylic acid lower alkyl esters, ketones, aldehydes, and glycerides. Specific examples include respectively, di-alkyl ethers, polyethylene glycols, alkyl ketones (such as acetone) and glyceryl 20 trialkylcarboxylates (such as glyceryl tri-acetate), glycerol, propylene glycol, and sorbitol.

0* .n detiocculated systems, many light solvents with little or no hydrophilic character are usually unsuitable on their own deflocculation will not occur in them).

Examples ot these are lower alcohols, such as ethanol, or higher alcohols, such as dodecanol, as well as alkanes and olefins. However, they can be combined with other liquid o materials which are surfactants or non-surfactants having the aforementioned 'preterred' kinds of molecular structure.

Preferably, the compositions of the invention contain the organic liquid phase (whether or not comprising liquid surfactant) in an amount of at least 10% by weight of the total composition. The amount of the solvent present in 13 C.3239 the composition may be as high as about 90%, but in most cases the practical amount will lie between 20 and 70% and preferably between 20 and 5C% by weight of the composition.

Preferably also, the compositions of the present invention contain a deflocculant (as hereinbefore defined) which may be any of those referred to in the published prior art, most preferably any described in EP-A-266 199, provided the deflocculant is not a bleach precursor.

The level of any deflocculant material in the composition can be optimised by the means described in the art but in very many cases is at least 0.01%, usually 0.1% 0 o °o 15 and preferably at least 1% by weight, and may be as high as 15% by weight. For most practical purposes, the amount ranges from 2-12%, preferably from 4-10% by weight, based on the final composition.

o o a e The compositions according to the present invention preferably also contain one or more other functional ingredients, for example selected from other detergency o builders, bleaches and (for hard surface cleaners) abrasives.

Detergency builders are those materials which counteract the effects of calcium, or other ion, water hardness, either by precipitation or by an ion sequestering effect. They comprise both inorganic and organic builders. They may also be sub-divided into the phosphorus-containing and non-phosphorus types.

In addition to aluminosilicates, the class of inorganic builders comprises various phosphate, carbonate, silicate and borate materials, par ,cularly the 14 C.3239 alkali-metal salt forms. Mixtures of these may also be used.

Examples of phosphorus-containing inorganic builders include the water-soluble salts, especially alkali metal pyrophosphates, orthophosphates, polyphosphates and phosphonates. Specific examples of inorganic phosphate builders include sodium and potassium phosphates and hexametaphosphates, as well as potassium tripolyphosphate.

Examples of non-phosphorus-containing inorganic builders, when include water-soluble alkali metal carbonates, bicarbonates, borates, and other silicates.

Specific examples include sodium carbonate (with or 15 without calcite seeds), potassium carbonate, sodium and potassium bicarbonates.

Examples of organic builders include the alkali o 00, metal, ammonium and substituted, citrates, succinates, S 20 malonates, fatty acid sulphonates, carboxymethoxy succinates, ammonium polyacetates, carboxylates, polycarboxylates, aminopolycarboxylates, polyacetyl o o0 carboxylates and polyhydroxsulphonates. Specific examples include sodium, potassium, lithium, ammonium and 25 substituted ammonium salts of ethylenediaminetetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, melitic acid, benzene polycarboxylic acids and citric acid. Other examples are organic phosphonate type sequestering agents such as those sold by Monsanto under the tradename of the Dequest range and alkanehydroxy phosphonates.

Other suitable organic builders inc'.ude the higher molecular weight polymers and co-polymers known to have builder properties, for example appropriate polyacrylic acid, polymaleic acid and polyacrylic/polymaleic acid 15 C.3239 co-polymers and their salts, such as those sold by BASF under the Sokalan Trade Mark.

Suitable bleaches include the halogen, particularly chlorine bleaches such as are provided in the form of alkalimetal hypohalites, e.g. hypochlorites. In the application of fabrics washing, the oxygen bleaches are preferred, for example in the form of an inorganic persalt, or a peroxy acid compound.

Typical examples of the suitable persalt bleach, compounds are alkalimetal peroborates, both tetrahydrates and monohydrates, alkali metal percarbonates, persilicates and perphosphates, of which sodium perborate is preferred.

0 The organic peroxyacid compound bleaches are preferably those which are solid at room temperatjre and most preferably should have a melting point of at least 50 0 C. Most commonly, they are the organic peroxyacids and 04 water-soluble salts thereof having the general formula C

II

S4 HO-O-C-R-Y t 46 25 wherein R is an alkylene or substituted alkylene group containing 1 to 20 carbon atoms or an arylene group containing from 6 to 8 carbon atoms, and Y is hydrogen, t halogen, alkyl, aryl or any group which provides an C anionic moiety in aqueous solution.

Another preferred class of peroxygen compounds which can be incorporated to enhance dispensing/dispersibility in water are the anhydrous perborates described for that purpose in the applicants' European patent specification EP-A-217,454.

16 C.3239 The preferred level of persalt bleach in the compositions of the invention is from 5% to 35% by weight, most preferably from 10% to 25% by weight.

When the composition contains abrasives for hard surface cleaning is a liquid abrasive cleaner), these will inevitably be incorporated as particulate solids. They may be those of the kind which are water insoluble, for example calcite. Suitable materials of this kind are disclosed in the applicants' patent specifications EP-A-50,887; EP-A-80,221; EP-A-140,452; EP-A-214,540 and EP 9,942, which relate to such abrasives when suspended in aqueous media. Water soluble abrasives may also be used.

°o0 00 a" The compositions of the invention optionally may also :o0 contain one or more minor ingredients such as tabric 0 0..

0 conditioning agents, enzymes, perfumes (including o 0 deoperfumes), micro-biocides, colouring agents, 0 20 fluorescers, soil-suspending agents (anti-redeposition agents), corrosion inhibitors, enzyme stabilizing agents, and lather depressants.

0 00 o 0 0 S" In general, the solids content of the product may be 25 within a very wide range, for example from 1-90%, usually from 10-80% and preferably from 15-70%, especially 15-50% by weight of the final composition. The components ot the 0i solid phase should be in particulate form and have an S 3t average particle size of less than 300 microns, preferably less than 200 microns, more preferably less than 100 microns, especially less than 10 microns. The particle size may even be of sub-micron size. The proper particle size can be obtained by using materials of the appropriate size or by milling the total product in a suitable milling apparatus.

t

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17 C.3239 The compositions are substantially non-aqueous, i.e.

they little or no free water, preferably no more than preferably less than especially less than 1% by weight of the total composition. It has been found by the applicants that the higher the water content, the more likely it is for the viscosity to be too high, or even for setting to occur. However, this may at least in part be overcome by use of deflocculants, especially in relatively high amounts.

Since the objective of a non-aqueous liquid will generally be to enable the formulator to avoid the negative influence of water on the components, e.g.

causing incompatibility of functional ingredients, it is 0o 15 clearly necessary to avoid the accidental or deliberate addition of water to the product at any stage in its life.

For this reason, special precautions are necessary in .0 manufacturing procedures and pack designs for use by the Sconsumer.

Thus during manufacture, it is preferred that all raw ~materials should be dry and (in the case of hydratable o salts) in a low hydration state, e.g. anhydrous phosphate builder, sodium perborate monohydrate and dry calcite 25 abrasive, where these are employed in the composition. In a preferred process, the dry, substantially anhydrous solids are blended with the liquid phase in a dry vessel.

In order to minimise the rate of sedimentation of the S solids, this blend is passed through a grinding mill or a combination of mills, e.g. a colloid mill, a corundum disc mill, a horizontal or vertical agitated ball mill, to achieve a particle size of 0.1 to 100 microns, preferably to 50 microns, ideally 1 to 10 microns. A preferred combination of such mills is a colloid mill followed by a horizontal ball mill since these can be operated under the conditions required to provide a narrow size distribution 18 C.3239 in the final product. Of course particulate material already having the desired particle size need not be subjected to this procedure and if desired, can be incorporated during a later stage of processing.

During this milling procedure, the energy input results in a temperature rise in the product and the liberation of air entrapped in or between the particles of the solid ingredients. It is therefore highly desirable to mix any heat sensitive ingredients into the product after the milling stage and a subsequent cooling step. It may also be desirable to de-aerate the product before addition of these (usually minor) ingredients and Soptionally, at any other stage of the process. Typical 4 15 ingredients which might be added at this stage are *404 perfumes and enzymes, but might also include highly to, temperature sensitive bleach components or volatile to° solvent components which may be desirable in the final rcomposition. However, it is especially preferred that volatile material be introduced after any step of aeration. Suitable equipment for cooling heat exchangers) and de-aeration will be known to those skilled o in the art.

Si o 25 It follows that all equipment used in this process should be completely dry, special care being taken after any cleaning operations. The same is true tor subsequent storage and packing equipment.

t t The present invention will now be illustrated by way of the following Examples.

19 C.3239 EXAMPLE 1 A control non-aqueous dispersion of 24% hydrated (18% H 2 0) Zeolite A4 and 15% sodium perborate monohydrate was prepared in nonionic surfactant (Plurafac RA30

C

13 15 fatty alcohol condensed with 4-5 moles ethylene oxide and 2-3 moles of propylene oxide). All percentages herein are by weight unless stated to the contrary.

Three identical compositions according to the invention was prepared as composition but with 5% by weight sodium metasilicate in place of an equivalent weight of the nonionic.

".15 The gas evolution was measured as the cumulative *volume released from 100g of product, after 1 day and 3 So days. For the 3 compositions the results were .so averaged.

S° 20 gas evolved ml/100g after Composition 1 day 3 days i C 17.0 27 av. 10.2 11.4 ii

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20 C.3239 EXAMPLE 2 The procedure of Example 1 was followed except that various alkaline materials were incorporated and the compositions consisted of: Zeolite 24% Sodium perborate monohydrate Plurafax RA30 56% Alkaline material The results obtained were as follows: Alkaline material Gas evolved ml/100g after o 1 day 3 days None* 17 27 Sodium tripolyphosphate 18.5 26 SSodium carbonate 15 26 0.5% Potassium hydroxide* 0 Sodium metasilicate 11.5 11.5 so balance made up by further nonionic surfactant.

25 These results show that the metasilicate was mo're capable of reducing the gas evolved after 1 day than any other alkaline material, with the exception of potassium hydroxide. After 3 days no further gas evolution had occurred in the metasilicate containing composition whereas all the other compositions had evolved further gas, even that containing the potassium hydroxide.

i 21 -C.3239 EXAMPLE 3 The following composition was prepared and the perborate therein was found to be acceptable stable on storage.

Ingredient bywt Plurafac RA30 42.95

ABSA

1 0.25 Sodium metasilicate 5.50 Partially hydrated zeolite 24.00 Polymer CP5 2 6.00 Sodium carboxymethyl cellulose 1.00 15 Sodium perborate monohydrate 15.00 SSodium carbonate (anhydrous) 4.00 0 Minors 1.30 0 0 0 Notes 1 Dodecyl benzene sulphonic acid in the free acid form.

0 2 Sokalan CP5 which is the sodium salt of a maleic acid/acrylic acid copolymer, ex BASF.

O t t

Claims (6)

1. A substantially non-aqueous liquid cleaning composition comprising solid particles of aluminosilicate builder dispersed in a liquid phase, said composition also comprising an alkalimetal metasilicate and being substantially free of bleach precursor.

2. A composition according to claim 1, wherein the alkalimetal metasilicate is sodium metasilicate.

3. A composition according to claim 1, comprising from 1% to 10% by weight of the alkalimetal metasilicate. 15

4. A composition according to claim 1, further comprising an inorganic persalt bleach. Io S'

5. A composition according to claim 1, further comprising a deflocculant. t 20

6. A composition according to claim 1, comprising: t 4 from 20% to 50% by weight of a liquid nonionic 1 surfactant; from 12% to 30% by weight of an aluminosilicate builder; from 10% to 2b% by weight of an inorganic persalt bleach; trom 0.1% to 15% by weight of an alkyl benzene sulphonic acid; and from 1% to 10% by weight of sodium metasilicate. DATED this 27th day of APRIL. 1989 UNILEVER PLC By its Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. L -j