Non-aqueous liquid cleaning products which contain modified silica

A non-aqueous liquid cleaning composition comprising a non-aqueous organic solvent, particles of solid material dispersed in the solvent and a dispersant, wherein the dispersant is a hydrophobically modified material.

The present invention relates to liquid non-aqueous cleaning products, 
especially non-aqueous liquid detergent compositions containing 
particulate solid materials. Non-aqueous liquids are those containing 
little or no water. 
In liquid detergents in general, especially those for the washing of 
fabrics, it is often desired to suspend particulate solids which have 
beneficial auxiliary effects in the wash, for example detergency builders 
to counteract water hardness, as well as bleaches. To keep the solids in 
suspension, generally some sort of stabilising system is necessary. 
Several different approaches have been used to provide solid-suspending 
properties in non-aqueous liquids. For example it has been proposed in GB 
1 600 981 to use dispersants, such as silica dispersants for the 
stabilisation of heavy duty liquid detergent compositions which contain 
builders dispersed in substantially water-free non-ionic liquid 
surfactants. Often, however, the use of silica dispersants for the 
stabilisation of non-aqueous liquid detergents, leads to the setting of 
the composition, possible resulting in an unacceptable high viscosity. 
FR-A-2 618 157 discloses non-aqueous liquid detergents comprising solid 
particles, a low density compound and an organophilic clay. 
EP 30 096 discloses non-aqueous liquid detergent compositions containing a 
dispersion of solids, which are free from dispersants, in particular free 
from silica containing dispersants. Applicants, however, have found that 
non-aqueous detergent compositions which are free from dispersants, in 
particular silica containing dispersants, sometimes suffer from physical 
instability. 
Surprisingly, it has now been found that the physical stability of 
non-aqueous liquid detergent compositions can be improved and the above 
described setting problems can be minimised, if hydrophobically modified 
dispersants are used. 
Accordingly the present invention relates to a substantially non-aqueous 
liquid cleaning product, comprising a non-aqueous organic solvent, 
particles of solid material dispersed in the solvent and a dispersant, 
wherein the dispersant is a hydrophobically modified material. 
Preferably hydrophobically modified (HM) silica containing dispersants are 
used. Preferred HM dispersant materials have a weight average particle 
size of from 0.005 to 5 micrometer, more preferred 0.01 to 3 micrometer, 
most preferred from 0.02 to 0.5 micrometer. The level of the HM dispersant 
material is preferably from 0.1 to 10% by weight of the composition, more 
preferred 0.3 to 5%, most preferred from 0.5 to 3%. 
PRODUCT FORM 
All compositions according to the present invention are liquid cleaning 
products. In the context of this specification, all references to liquids 
refer to materials which are liquid at 25.degree. C. at atmospheric 
pressure. 
Preferably compositions of the invention have a viscosity of less than 
2,500 mPa.s at 21 S.sup.-1, more preferred 100-2,000 mPa.s. 
They may be formulated in a very wide range of specific forms, according to 
the intended use. They may be formulated as cleaners for hard 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 
form of specialised cleaning products, such as for surgical apparatus or 
artificial dentures. They may also be formulated as agents for washing 
and/or conditioning of fabrics. 
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 
selected from surfactants, enzymes, bleaches, microbiocides, (for fabrics) 
fabric softening agents and (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. 
HYDROPHOBICALLY MODIFIED MATERIAL 
Compositions of the invention contain a hydrophobically modified dispersant 
material. For the purpose of the present invention, a dispersant material 
is a material, of which the main purpose is to stabilise the composition. 
Hydrophobically modified dispersant materials are particulate materials, 
of which the outer surface has chemically been treated to reduce the 
hydrophilic nature thereof. 
Preferably the number of hydroxy- and/or acid- groups at the surface of the 
particles is reduced by the hydrophobing treatment. Suitable reactions 
include esterification or etherification of the hydrophilic groups. 
Preferably the hydrophobing treatment involves at least 10% of the 
hydrophilic groups at the surface of the particle, more preferably from 40 
to 95%, most preferably from 50 to 90%. Partial hydrophobing is preferred 
over complete hydrophobation. 
Preferably HM silica containing dispersants are used. The hydrophobation of 
the silica particles preferably involves the substitution of the free 
hydroxy-groups at the outer surface of the silica particles by less 
hydrophilic groups. More preferably the surface hydroxy-groups are 
substituted by short alkyl groups e.g. by methyl groups. 
SURFACTANT 
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. However, in some cases the surfactants 
may undergo a phase change in the composition. 
In general, surfactants for use in the compositions of the invention 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" published by the McCutcheon division of 
Manufacturing Confectioners Company or in "Tensid-Taschenbuch", H. Stache, 
2nd Edn., Carl Hanser Verlag, Munchen & Wien, 1981. 
In respect of all surfactant materials, but also with reference to all 
ingredients described herein as examples of components in compositions 
according to the present invention, unless the context requires otherwise, 
the term "alkyl" refers to a straight or branched alkyl moiety having from 
1 to 30 carbon atoms, whereas lower alkyl refers to a straight or branched 
alkyl moiety of from 1 to 4 carbon atoms. These definitions apply to alkyl 
species however incorporated (e.g. as part of an aralkyl species). Alkenyl 
(olefin) and alkynyl (acetylene) species are to be interpreted likewise 
(i.e. in terms of configuration and number of carbon atoms) as are 
equivalent alkylene, alkenylene and alkynylene linkages. For the avoidance 
of doubt, any reference to lower alkyl or C.sub.1-4 alkyl (unless the 
context so forbids) is to be taken specifically as a recitation of each 
species wherein the alkyl group is (independent of any other alkyl group 
which may be present in the same molecule) methyl, ethyl, iso-propyl, 
n-propyl, n-butyl, iso-butyl and t-butyl, and lower (or C.sub.1-4) 
alkylene is to be construed likewise. 
NON-IONIC SURFACTANTS 
Nonionic detergent surfactants are well-known in the art. They normally 
consist of a water-solubilizing polyalkoxylene or a mono- or 
di-alkanolamide group in chemical combination with an organic hydrophobic 
group derived, for example, from alkylphenols in which the alkyl 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), 
preferably 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 10 to about 20 carbon atoms 
and the alkyloyl group having from 1 to 3 carbon atoms. In any of the 
mono- and di- 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 preferably 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 the 
applicants' published European specification EP-A-225,654, especially for 
use as all or part of the liquid phase. 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.sub.11-13 alcohols with (say) 3 or 7 moles of ethylene oxide. These may 
be used as the sole nonionic surfactants or in combination with those of 
the described in the last-mentioned European specification, especially as 
all or part of the liquid phase. 
Another class of suitable nonionics comprise the alkyl polysaccharides 
(polyglycosides/oligosaccharides) such as described in any of 
specifications U.S. Pat. No. 3,640,998; U.S. Pat. No. 3,346,558; U.S. Pat. 
No. 4,223,129; EP-A-92,355; EP-A-99,183; EP 70,074, '75, '76, '77; EP 
75,994, '95, '96. 
Mixtures of different nonionic detergent surfactants may also be used. 
Mixtures of nonionic detergent surfactants with other detergent 
surfactants such as anionic, cationic or ampholytic detergent surfactants 
and soaps may also be used. 
Preferably the level of nonionic surfactants is from 10-90% by weight of 
the composition, more preferably 20-70%, most preferably 35 to 50% by 
weight. 
ANIONIC SURFACTANTS 
Examples of suitable anionic detergent surfactants are alkali metal, 
ammonium or alkylolamine salts of alkylbenzene sulphonates having from 10 
to 18 carbon atoms in the alkyl group, alkyl and alkylether sulphates 
having from 10 to 24 carbon atoms in the alkyl group, the alkylether 
sulphates having from 1 to 5 ethylene oxide groups, and olefin sulphonates 
prepared by sulphonation of C.sub.10-24 alpha-olefins and subsequent 
neutralization and hydrolysis of the sulphonation reaction product. 
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 in the liquid phase or they will be dissolved therein. 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. 
THE NON-AQUEOUS ORGANIC SOLVENT 
As a general rule, the most suitable liquids to choose as the liquid phase 
are those organic materials having polar molecules. In particular, those 
comprising a relatively lipophilic part and a 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, are one preferred class 
of material for the liquid phase. 
Non-surfactants which are suitable for use as the liquid phase 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 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- N-substituted 
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 trialkylcarboxylates (such as glyceryl 
tri-acetate), glycerol, propylene glycol, and sorbitol. 
Many light solvents with little or no hydrophilic character are in most 
systems, unsuitable on their own Examples of 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 materials. 
LEVEL OF LIQUID PHASE 
Preferably, the compositions of the invention contain the 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 liquid phase present 
in 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 35 and 
50% by weight of the composition. 
SOLIDS CONTENT 
In general, the solids content of the product may be within a very wide 
range, for example from 10-90%, usually from 30-80% and preferably from 
50-65% by weight of the final composition. The solid phase is preferably 
in particulate form and preferably has a weight 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. In order to control aggregation of the 
solid phase leading to unredispersible settling or setting of the 
composition, it is preferred to include a deflocculant therein. 
OTHER INGREDIENTS 
In addition to the components already discussed, there are very many other 
ingredients which can be incorporated in liquid cleaning products. 
There is a very great range of such other ingredients and these will be 
choosen according to the intended use of the product. However, the 
greatest diversity is found in products for fabrics washing and/or 
conditioning. Many ingredients intended for that purpose will also find 
application in products for other applications (e.g. in hard surface 
cleaners and warewashing liquids). 
METAL OXIDES 
For reducing the clear layer separation of liquid detergent compositions of 
the invention, surprisingly it has been found that the combined use of HM 
particles and particulate metal oxides is especially advantageous. 
Preferred suspended metal oxides have a bulk density of 200 to 1,000 g/l, 
more preferred 250 to 800 g/l, especially preferably 300 to 700 g/l, most 
preferably from 400 to 650 g/l. 
Preferably the metal oxide is selected from calcium oxide, magnesium oxide 
and aluminium oxide, most preferably magnesium oxide is used. 
The weight average particle size of the metal oxide is preferably from 0.1 
to 200 micrometer, more preferably from 0.5 to 100 micrometer, most 
preferred from 2 to 70 micrometer. The level of metal oxide is preferably 
from 0.1 to 7% by weight of the composition, more preferred from 0.5 to 
5%, most preferred from 1 to 4%. 
DETERGENCY BUILDERS 
The 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, the latter being preferred when environmental 
considerations are important. 
In general, the inorganic builders comprise the various phosphate-, 
carbonate-, silicate-, borate- and aluminosilicates-type materials, 
particularly the alkali-metal salt forms. Mixtures of these may also be 
used. 
Examples of phosphorus-containing inorganic builders, when present, include 
the water-soluble salts, especially alkali metal pyrophosphates, 
orthophosphates, polyphosphates and phosphonates. Specific examples of 
inorganic phosphate builders include sodium and potassium 
tripolyphosphates, phosphates and hexametaphosphates. 
Examples of non-phosphorus-containing inorganic builders, when present, 
include water-soluble alkali metal carbonates, bicarbonates, borates, 
silicates, metasilicates, and crystalline and amorphous aluminosilicates. 
Specific examples include sodium carbonate (with or without calcite 
seeds), potassium carbonate, sodium and potassium bicarbonates, silicates 
and zeolites. 
Examples of organic builders include the alkali metal, ammonium and 
substituted ammonium, citrates, succinates, malonates, fatty acid 
sulphonates, carboxymethoxy succinates, ammonium polyacetates, 
carboxylates, polycarboxylates, aminopolycarboxylates, polyacetyl 
carboxylates and polyhydroxsulphonates. Specific examples include sodium, 
potassium, lithium, ammonium and 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 include the higher molecular weight 
polymers and co-polymers known to have builder properties, for example 
appropriate polyacrylic acid, polymaleic acid and polyacrylic/polymaleic 
acid co-polymers and their salts, such as those sold by BASF under the 
Sokalan Trade Mark. 
Preferably the level of builder materials is from 0-75% by weight of the 
composition, more preferred 5-50%, most preferred 10-40%. 
THE DEFLOCCULANT 
Preferably compositions of the invention also comprise a deflocculant 
material. In principle, any material may be used as a deflocculant 
provided it fulfils the deflocculation test described in European Patent 
Specification EP-A-266199 (Unilever). The capability of a substance to act 
as a deflocculant will partly depend on the solids/liquid phase 
combination. However, especially preferred are acids. 
Some typical examples of deflocculants include the alkanoic acids such as 
acetic, propionic and stearic and their halogenated counterparts such as 
trichloracetic and trifluoracetic as well as the alkyl (e.g. methane) 
sulphonic acids and aralkyl (e.g. paratoluene) sulphonic acids. 
Examples of suitable inorganic mineral acids and their salts are 
hydrochloric, carbonic, sulphurous, sulphuric and phosphoric acids; 
potassium monohydrogen sulphate, sodium monohydrogen sulphate, potassium 
monohydrogen phosphate, potassium dihydrogen phosphate, sodium 
monohydrogen phosphate, potassium dihydrogen pyrophosphate, tetrasodium 
monohydrogen triphosphate. 
Other organic acids may also be used as deflocculants, for example formic, 
lactic, amino acetic, benzoic, salicylic, phthalic, nicotinic, ascorbic, 
ethylenediamine tetraacetic, and aminophosphonic acids, as well as longer 
chain fatty carboxylates and triglycerides, such as oleic, stearic, lauric 
acid and the like. Peracids such as percarboxylic and persulphonic acids 
may also be used. 
The class of acid deflocculants further extends to the Lewis acids, 
including the anhydrides of inorganic and organic acids. Examples of these 
are acetic anhydride, maleic anhydride, phthalic anhydride and succinic 
anhydride, sulphur-trioxide, diphosphorous pentoxide, boron trifluoride, 
antimony pentachloride. 
"Fatty" anions are very suitable deflocculants, and a particularly 
preferred class of deflocculants comprises anionic surfactants. Although 
anionics which are salts of alkali or other metals may be used, 
particularly preferred are the free acid forms of these surfactants 
(wherein the metal cation is replaced by an H.sup.+ cation, i.e. proton). 
These anionic surfactants include all those classes, sub-classes and 
specific forms described in the aforementioned general references on 
surfactants, viz, Schwartz & Perry, Schwartz Perry and Berch, 
McCutcheon's, Tensid-Taschenbuch; and the free acid forms thereof. Many 
anionic surfactants have already been described hereinbefore. In the role 
of deflocculants, the free acid forms of these are generally preferred. 
In particular, some preferred sub-classes and examples are the C.sub.10 
-C.sub.22 fatty acids and dimers thereof, the C.sub.8 -C.sub.18 
alkylbenzene sulphonic acids, the C.sub.10 -C.sub.18 alkyl- or alkylether 
sulphuric acid monoesters, the C.sub.12 -C.sub.18 paraffin sulphonic 
acids, the fatty acid sulphonic acids, the benzene-, toluene-, xylene- and 
cumene sulphonic acids and so on. Particularly are the linear C.sub.12 
-C.sub.18 alkylbenzene sulphonic acids. 
As well as anionic surfactants, zwitterionic-types can also be used as 
deflocculants. These may be any described in the aforementioned general 
surfactant references. One example is lecithin. 
The level of the deflocculant material in the composition can be optimised 
by the means described in the aforementioned EP-A-266199, but in very many 
cases is at least 0.01%, usually 0.1% 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. 
THE BLEACH SYSTEM 
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, preferably with a bleach 
precursor, or as a peroxy acid compound. 
In the case of the inorganic persalt bleaches, the activator makes the 
bleaching more effective at lower temperatures, i.e. in the range from 
ambient temperature to about 60.degree. C., so that such bleach systems 
are commonly known as low-temperature bleach systems and are well-known in 
the art. The inorganic persalt such as sodium perborate, both the 
monohydrate and the tetrahydrate, acts to release active oxygen in 
solution, and the activator is usually an organic compound having one or 
more reactive acyl residues, which cause the formation of peracids, the 
latter providing for a more effective bleaching action at lower 
temperatures than the peroxybleach compound alone. 
The ratio by weight of the peroxybleach compound to the activator is 
preferably from about 20:1 to about 1:1, preferably from about 10:1 to 
about 2:1, most preferably 5:1 to 3.5:1. Whilst the amount of the bleach 
system, i.e. peroxybleach compound and activator, may be varied between 
about 5% and about 35% by weight of the total liquid, it is preferred to 
use from about 6% to about 30% of the ingredients forming the bleach 
system. Thus, the preferred level of the peroxybleach compound in the 
composition is between about 5.5% and about 27% by weight, while the 
preferred level of the activator is between about 0.5% and about 14%, most 
preferably between about 1% and about 5% by weight. 
Typical examples of the suitable peroxybleach compounds are alkalimetal 
perborates, both tetrahydrates and monohydrates, alkali metal 
percarbonates, persilicates and perphosphates, of which sodium perborate 
and sodium percarbonate are preferred. 
It is particularly preferred to include in the compositions, a stabiliser 
for the bleach or bleach system, for example ethylene diamine 
tetramethylene phosphonate and diethylene triamine pentamethylene 
phosphonate or other appropriate organic phosphonate or salt thereof, such 
as the Dequest range hereinbefore described. These stabilisers can be used 
in acid or salt form, such as the calcium, magnesium, zinc or aluminium 
salt form. The stabiliser may be present at a level of up to about 1% by 
weight, preferably between about 0.1% and about 0.5% by weight. 
Preferred activator materials are TAED and glycerol triacetate. The 
applicants have also found that liquid bleach activator, such as glycerol 
triacetate and ethylidene heptanoate acetate, isopropenyl acetate and the 
like, also function suitably as a material for the liquid phase, thus 
obviating or reducing any need of additional relatively volatile solvents, 
such as the lower alkanols, paraffins, glycols and glycolethers and the 
like, e.g. for viscosity control. 
MISCELLANEOUS OTHER INGREDIENTS 
Other ingredients comprise those remaining ingredients which may be used in 
liquid cleaning products, such as fabric conditioning agents, enzymes, 
perfumes (including deoperfumes), micro-biocides, colouring agents, 
fluorescers, soil-suspending agents (anti-redeposition agents), corrosion 
inhibitors, enzyme stabilising agents, and lather depressants. 
Amongst the fabric conditioning agents which may be used, either in fabric 
washing liquids or in rinse conditioners, are fabric softening materials 
such as fabric softening clays, quaternary ammonium salts, imidazolinium 
salts, fatty amines and cellulases. 
Enzymes which can be used in liquids according to the present invention 
include proteolytic enzymes, amylolytic enzymes and lipolytic enzymes 
(lipases). Various types of proteolytic enzymes and amylolytic enzymes are 
known in the art and are commercially available. They may be incorporated 
as "prills" or "marumes", suspensions etc. 
The fluorescent agents which can be used in the liquid cleaning products 
according to the invention are well known and many such fluorescent agents 
are available commercially. Usually, these fluorescent agents are supplied 
and used in the form of their alkali metal salts, for example, the sodium 
salts. The total amount of the fluorescent agent or agents used in a 
detergent composition is generally from 0.02-2% by weight. 
When it is desired to include anti-redeposition agents in the liquid 
cleaning products, the amount thereof is normally from about 0.1% to about 
5% by weight, preferably from about 0.2% to about 2.5% by weight of the 
total liquid composition. Preferred anti-redeposition agents include 
carboxy derivatives of sugars and celluloses, e.g. sodium carboxymethyl 
cellulose, anionic poly-electrolytes, especially polymeric aliphatic 
carboxylates, or organic phosphonates. 
WATER LEVEL 
The compositions are substantially non-aqueous, i.e. they contain little or 
no free water, preferably no more than 5%, preferably less than 3%, 
especially less than 1% by weight of the total composition. It has been 
found that the higher the water content, the more likely it is for the 
viscosity to be too high, or even for setting to occur. 
USE 
Composition in accordance with the present invention may be used for 
several detergency purposes, for example the cleaning of surfaces and the 
washing of fabrics. For the washing of fabrics, preferably an aqueous 
liquor containing 0.05 to 10%, more preferably 0.1 to 2%, of the 
non-aqueous detergent composition of the invention is used. 
PROCESSING 
During manufacture, it is preferred that all raw materials should be dry 
and (in the case of hydratable salts) in a low hydration state, e.g. 
anhydrous phosphate builder, sodium perborate monohydrate and dry calcite 
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. If deflocculant materials are used, these 
should preferably--at least partly--be mixed with the liquid phase, prior 
to the addition of the solids. In order to minimise the rate of 
sedimentation of the 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 0.5 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 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 
optionally, at any other stage of the process. Typical ingredients which 
might be added at this stage are perfumes and enzymes, but might also 
include highly temperature sensitive bleach components or volatile solvent 
components which may be desirable in the final composition. However, it is 
especially preferred that volatile material be introduced after any step 
of de-aeration. Suitable equipment for cooling (e.g. heat exchangers) and 
de-aeration will be known to those skilled in the art. 
It follows that all equipment used in this process should preferably be 
completely dry, special care being taken after any cleaning operations. 
The same is true for subsequent storage and packing equipment. 
The invention will further be illustrated in the examples.