Note: Descriptions are shown in the official language in which they were submitted.
~ W094/~009 21 S ~ 6 0 7 PCT~4/00822
LIOUID CLEANING PRODUCTS
FIELD OF INVENTION
The present invention relates to liquid non-aqueous
cleaning products, especially substantially non-aqueous
liquid detergent compositions containing partiGulate solid
materials. Substantially non-aqueous liquids are those
containing little or no water.
PRIOR ART AND BACKGROUND OF THE INVENTION
Non-aqueous detergent liquids have been proposed for a
number of uses, such as fabric washing and dishwashing.
They have advantages over powder products in that they are
more rapidly dispersed in water. Further advantages over
powder products are the possibility of automatic dosing and
higher obtainable product densities, resulting in lower
transportation and packaging costs.
Non-aqueous detergent liquids have advantages over aqueous
liquid products in that they are capable of including
water-sensitive ingredients such as bleaches.
With regard to the use in industrial washing machines of
non-aqueous liquid detergent compositions containing a
particulate solid phase dispersed in a liquid phase, it is
important that the viscosity of such compositions should be
as low as possible whilst still maintaining acceptable
stability against separation of the suspended particulate
solid material. The reason is that products used in
industrial washing machines are usually pumped through long
supply lines from the dosing equipment to the point of use
inside the washing machine.
It has been described in WO 91/12313 that non-aqueous
liquid detergent compositions comprising sodium
metasilicate, having an improved stability against
sedimentation of the particulate solid material suspended
W094/~009 PCT~4/00822
2 1 ~ 7 2
therein and having a reduced tendency to clear layer
separation upon storage, can be formulated by including
therein a metal oxide having a bulk density of 200 to 1000
g/l.
Furthermore, W0 91/12312 relates to a non-aqueQus liquid
cleaning product comprising particles of~olid material
dispersed in a solvent, a deflocculant material, and a
hydrophobically modified silica containing dispersant,
lo whereby the stability of the product is shown to be
improved by said dispersant. This patent document does,
however, not disclose non-aqueous liquid composit-ions
containing considerable amounts of alkaline material, such
as sodium metasilicate, which are contained in the non-
aqueous liquid composition according to the presentinvention.
Detergent compositions suitable for use in industrial
washing machines generally contain a considerable level of
material which gives a high alkalinity in the wash liguor.
This type of material is often referred to as either buffer
salt or alkalinity booster. It is known that sodium
metasilicate may effectively perform the function of both
builder material and alkalinity booster. Therefore, sodium
metasilicate is a preferred component of industrial
detergent products.
However, we have found that only anhydrous sodium
metasilicate as a constituent of a non-aqueous liquid
composition has resulted in a non-aqueous liquid with an
acceptable viscosity so that it can be dosed without having
to use complicated apparatus. Moreover, an acceptable
viscosity of such non-aqueous liquids containing anhydrous
sodium metasilicate could only be obtained at relatively
low levels of particulate solids dispersed therein.
W094l~009 21 5 9 6 D 7 PCT~4/00822
3
In this respect, it has been disclosed by European Patent
Application No. 92 203 446.7 that the incorporation of a
special type of anhydrous sodium metasilicate, i.e.
substantially amorphous metaslicate, results in a low
viscosity, pourable, easy-to-process formulation. It has,
furthermore, been described in this document that the use
of anhydrous substantially amorphous sodium metasilicate as
a component of non-aqueous liquids allows a larger amount
of solids to be incorporated for obtaining formulations
with a good viscosity and stability. Although the stability
improvement disclosed by this document is significant, a
further stability improvement is considered to be.desirable
because of the resulting better storage stability of the
non-aqueous liquid concerned.
In view of the foregoing, it is an object of the present
invention to provide a non-aqueous liquid detergent
composition having a good viscosity and stability against
se~i~entation, and containing considerable amounts of
anhydrous sodium metasilicate.
It has now, surprisingly, been found that this object could
be achieved by including in said non-aqueous liquid
composition, a hydrophobically modified silica containing
dispersant.
DEFINITION OF THE INVENTION
The present invention provides a substantially non-aqueous
liquid detergent composition comprising a liquid phase and
a particulate solid phase dispersed therein, said solid
phase comprising from 10 to 60% by weight of sodium
metasilicate and from 0.1 to 10% by weight of a
hydrophobically modified silica containing dispersant, both
concentration ranges being based on the total weight of the
composition, said sodium metasilicate containing less than
8% by weight of water.
W094/~009 PCT~4/00822
~IS 960~ 4
The present invention also relates to the use of
hydrophobically modified silica as a stabilising agent in a
substantially non-aqueous liquid detergent composition
comprising sodium metasilicate, said metasilicate
containing less than 8% by weight of water.
DETAILED DESCRIPTION OF THE INVENTION ~-
All compositions according to the present invention are
substantially non-aqueous liquid cleaning~roducts. In the
context of this specification, all referehces to li~uids
refer to materials which are fluid at 25C at atmospheric
pressure.
The compositions are substantially non-aqueous, i.e. they
contain little or no free water, generally less than 10% by
weight, preferably less than 3% by weight, more preferably
less than 1% by weight. 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. Setting is
characterised by an increase in product viscosity during
storage as a result of the reversible build-up of a
structure within the non-aqueous liquid with time. Setting
could eventually result in a product which cannot be poured
or pumped without prior shaking or stirring.
Preferably, compositions of the invention have a viscosity
of less than 2,500 mPa.s at a shear rate of 21 S-l, a
viscosity range of 500-2,000 mPa.s being more preferred (as
measured on a Haake rotoviscometer RV20 with a mv2p head at
25C after 5 minutes). Most preferably, the viscosity is in
between 1000 and 2000 mP.s at 21 S-l, as measured using the
same method.
The compositions according to the invention 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 twith or without abrasive) or as agents for
~ W094/~009 21 5 9 6 0 7 PCT~4/00822
warewashing either by hand or by mechanical means. They may
also be formulated as agents for washing and/or
conditioning of fabrics. Those last-mentioned products
constitute an especially preferred form of the present
invention because in that role there is a very great need
to be able to incorporate substantial amounts of various
kinds of solids. These compositions may be of the kind used
for pre-treatment of fabrics with the composition, neat or
diluted, before they are rinsed 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 fabrics are contacted.
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 presen~, as well as other
ingredients commonly used in the relevant product form.
The sodium metasilicate
The concentration of sodium metasilicate in a non-aqueous
liquid detergent composition according to the invention is
generally in the range of 10-60% by weight, preferably
25-5S% by weight, more preferably 30-55% by weight, of the
composition.
The type of sodium metasilicate applied in compositions of
the invention is substantially anhydrous sodium
metasilicate which most preferably consists of sodium
oxide, silicon dioxide, about 0-3 % by weight of carbon
dioxide, and about 2-3% by weight of water, whereby the
molar ratio of sodium oxide to silicon dioxide is in the
range from 0.8 to 1.2. This type of sodium metasilicate
W094/~009 215 9 ~ ~ 7 PCT~W4/00822 ~
typically consists of 50.5+2.0~ by weight of sodium oxide,
45.5+2.0% by weight of silicon dioxide, 1.5% by weight of
carbon dioxide and 2.5% by weight of water.
The water content of the sodium metasilicate (as analysed
by heating a sample up to 600C for 1 hou~) should not
exceed an upper level of 8% by weight, more preferably 5%
by weight, a maximum water content of ~% by weight being
most preferred.
The type of sodium metasilicate applied in the non-aqueous
liquid composition of the invention is, preferably,
substantially crystalline sodium metasilicate. This type of
sodium metasilicate may contain at most 10% by weight,
preferably 1% by weight of amorphous sodium metasilicate
having no crystalline order. In this context, substantially
crystalline sodium metasilicate is defined as material that
shows at most 10~ by weight of said material having no
crystalline order when applying X-ray crystallography
techniques.
The liquid and solid Phase
Preferably, the detergent compositions of the invention
contain the liquid phase 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% by weight, but in most cases the practical amount will
lie between 20 and 70% and preferably between 35 and 50% by
weight of the composition.
Preferably, the liquid phase comprises liquid nonionic
surfactant. For use in fabric washing and carpet washing,
the liquid phase preferably contains from 30 to 50% by
weight of liquid nonionic surfactant. For use in mechanical
dishwashing, lower liquid nonionic surfactant levels are
generally applied, typically less than 10% by weight,
preferably between 1 and 3% by weight of the total
~ W094/~009 215 9 6 0 7 PCT~W4/00822
formulation. The rest of the liquid phase may in this case
contain a solvent as described below.
The total solids content of compositions according to the
invention is generally in the range of from 10 to 90%, but
in most cases the practical total solids conte~t will be in
the range of from 30 to 80% by weight of the total
composition, a range of from 50 to 65% by weight being more
preferred. Most preferably, the total solids content does
not exceed 40% by volume of the total composition.
The solid phase is generally in particulate form and
usually 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.
HYdrO~hObiCa 1 1Y modified silica
Compositions of the invention comprise hydrophobically
modified (HM) silica as a dispersant material. For the
purpose of the present invention, a dispersant material is
a material whose main purpose is to stabilise the
composition. Furthermore, HM-dispersant materials, such as
HM-modified silica, are particulate materials, of which the
outer surface has been chemically treated to reduce the
hydrophilic nature thereof.
Preferably, the number of hydroxy and/or acid groups at the
surface of the HM silica particles is reduced by a
hydrophobing treatment. Suitable reactions include
esterification or etherification of the hydrophilic groups
present at the outer surface of the particles. Preferably,
the hydrophobing treatment involves at least 10%, more
preferably from 40 to 95%, most preferably from 50 to 90%,
W094/~009 PCT~4/00822
215 9~ 8
of these hydrophilic groups. Partial hydrophobing is
preferred over complete hydrophobation.
The hydrophobation of the silica particles preferably
involves the substitution of the free hydroxy groups at the
outer surface thereof by less hydrophilic group~s. More
preferably, the surface hydroxy groups are substituted by
short alkyl groups, e.g. by methyl groups.L 2
Preferred HM silica-containing dispersant materials have a
weight average particle size of from 0.005 to 10 microns,
more preferably 0.01 to 5 microns, most preferably 0.01 to
3 microns.
The level of HM silica-dispersant material is suitably from
0.1 to 10% by weight, preferably 0.3 to 5% by weight, more
preferably 0.5 to 3% by weight of the composition.
Surfactant material
Particularly when intended to be used for fabric washing,
the non-aqueous liquids of the invention will generally
contain one or more surfactant agents. Where surfactants
are solids, they will usually be dispersed or dissolved in
the liquid phase. Where they are liquid, 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 1959), 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
~ W094l~009 9 ~ 21 ~ 9 6 ~ 7 PCT~4/00822
Hanser Verlag, Munchen & Wien, 1981.
In respect of all surfactant materials, but also with
respect 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 refer to alkyl species
however incorporated (e.g. as part of an aralkyl species).
Nonionic surfactants
The preferred type of detergent surfactant present in non-
aqueous liquids of the invention is nonionic surfactant.
Nonionic detergent surfactants are well known in the art.
They normally consist of a water-solubilising
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
2S having from 8 to 20 carbon atoms, monocarboxylic acids
having from 10 to about 24 carbon atoms in the alkyl group
and polyoxy propylenes. 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 alkyoyl group having from 1 to 3 carbon atoms. In any
of the mono- and di- alkanolamide derivatives, optionally
there may be a polyoxyalkylene moiety ~oining 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 ethylene oxide and propylene oxide
groups.
W094/~009 21 S 9 ~ 0 7 PCT~4/00822 ~
Among the latter class, particularly preferred are those
described in 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~ 3 alcohols with (say) 3 to 7
moles of ethylene oxide. These may be used as the sole
nonionic surfactant or in combination with those 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 US-A-3,640,998; US-A-3,346,558;
US-A-4,223,129; EP-A-92,355; EP-A-99,183.
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. Generally, the level of nonionic surfactants is from
lO to 90% by weight of the composition, preferably from 20
to 70%, most preferably from 35 to 50% by weight.
Anionic surfactants
Examples of anionic detergent surfactants suitable to be
included in compositions according to the present
invention, are alkali metal, alkaline earth metal, ammonium
or alkylol amine salts of alkylbenzene sulphonates having
from lO to 18 carbon atoms in the alkyl group, alkyl and
alkylether sulphates having from lO 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 Cl0_24 alpha-olefins and subsequent
neutralisation and hydrolysis of the sulphonation reaction
product. Preferably, the level of anionic surfactants is in
W094l~009 PCT~W4100822
11 2159~07
between 1 and 15% by weight of the composition, more
preferably between 2 and 10% by weight.
Before incorporation, all anionic surfactants will either
be liquid, in which case, in the composition they will
constitute all or part of the liquid phase, or,they will be
solid, 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.
Detergency builders
In addition to the above-described sodium metasilicate, the
detergency builder present in compositions according to the
invention may include any material capable of reducing the
level of free calcium and magnesium ions in the wash liquor
and will preferably provide the composition with other
beneficial properties such as the generation of an alkaline
pH and the suspension of soil removed from the fabric. The
level of the total amount of detergency builder including
sodium metasilicate present in compositions according to
the invention may be from lO to 70% by weight, preferably
from 30 to 60% by weight.
Suitable builders comprise both inorganic and organic
builders. They may also be subdivided 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
aluminosilicate-type materials, particularly the alkali
W094t~009 PCT~4100822 ~
~5~0~ 12
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. Spèc~fic ~mn~ es of
inorganic phosphate builders inc~l~de sodium and potassium
tripolyphosphates, phosphates à~d hexametaphosphates.
Examples of non-phosphorus-containing inorganic builders,
when present, include water-soluble alkali metal
carbonates, bicarbonates, borates, silicates, and.
crystalline and amorphous silicates. Specific examples
include sodium carbonate (with or without calcite seeds),
potassium carbonate, sodium and potassium bicarbonates, and
zeolites.
Examples of suitable organic builders include the alkali
metal, ammonium and substituted ammonium, citrates,
succinates, malonates, fatty acid sulphonates,
carboxymetoxy succinates, ammonium polyacetates,
carboxylates, polycarboxylates, aminopolycarboxylates,
polyacetyl carboxylates and polyhydroxy sulphonates.
Specific examples include sodium, potassium, lithium,
ammonium and substituted ammonium salts of ethylene diamine
tetraacetic 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.
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
~ W094l~009 PCT~4/00822
13 2159~07
copolymers and their salts, particularly those sold by BASF
under the Sokalan Trade Mark. Other examples of suitable
organic builders of this type are acrylate/methacrylate
copolymers and homopolymers which may also be added as
stabilisers against sedimentation and for anti-ashing and
anti-redeposition purposes.
The bleach system
It was found that very stable bleach-containing,
substantially non-aqueous liquid detergent compositions
could be obtained when applying the afore-described
hydrophobically modified silica as a constituent thereof.
Bleaches which are suitable for non-aqueous compositions of
the invention include the halogen, particularly chlorine
bleaches such as provided in the form of alkali metal
hypohalites, e.g. hypochlorites. Particularly 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 temperatures
to about 60C, so that such bleach systems are commonly
known as low-temperature bleach systems. They are well
known in the art. The inorganic persalt, such as sodium
perborate monohydrate, 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 temperature than the
peroxybleach compound alone.
The ratio by weight of the peroxybleach compound to the
bleach activator is generally from about 20:1 to about 1:1,
preferably from about lO:l to about 2:1, most preferably
W094/~009 PCT~4/00822
7 14
from 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 non-
aqueous liquid, it is preferred to use from about 6% to
about 30% by weight of the lngredients forming the bleach
system. Thus the preferred~ltevel of the peroxybleach
compound in the composit`ion is between about 5.5% and about
27% by weight, while the preferred level of the activator
is between about 0.5~ and 14% by weight, most preferably
between about 1~ and about 5~ by weight.
Typical examples of suitable peroxy bleach compounds are
alkali metal perborates, both tetrahydrates and
monohydrates, alkali metal percarbonates, persilicates and
perphosphates, of which sodium perborate and, particularly,
sodium percarbonate are preferred. Preferred activator
materials are TAED and glycerol triacetate.
It is particularly preferred to include in the compositions
of the invention containing a bleach or bleach system, 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 magnesium, calcium, zinc
or aluminium salt form. The stabiliser may be present at a
level of up to about 1% by weight, preferably between about
O.1 and about 0.5% by weight.
The deflocculant
Preferably, compositions of the invention also comprise a
deflocculant material. In principle, any material may be
used as a deflocculant provided that it fulfils the
deflocculation test described in EP-A-266,199 (Unilever).
The capability of a substance to act as a deflocculant will
partly depend on the solids/liquid phase combination.
~ W094/~009 215 9 6 0 7 PCT~4/00822
Especially preferred deflocculants are acids.
Some typical examples of deflocculants include the alkanoic
acids such as acetic, propionic and stearic acid and their
halogenated counterparts such as trichloroacetic 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.
Other organic acids may also be used as deflocculants, for
example formic, lactic, amino acetic, benzoic, salicylic,
phthalic, nicotinic, ascorbic, ethylene diamine
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.
"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+-cation, i.e. proton).
These anionic surfactants include all those classes, sub-
classes and specific forms described in the afore-mentioned
general references on surfactants, viz. Schwartz & Perry,
Schwartz Perry and Berch, McCutcheon's, Tensid-Taschenbuch.
W094/~009 PCT~4/00822
2 ~ 5 ~ 16 ~
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 C1O_C22 fatty acids and dimers thereof, the C8_cl8
alkylbenzene sulphonic acids,the C1O-~ alkyl or
alkylether sulphuric acid monoesters~;the C12-C18 paraffin
sulphonic acids, the fatty acid su ~honic acids, the
benzene, toluene, xylene, and cum-e~e sulphonic acids and so
on.
The level of the deflocculant material in the composition
can be optimised by the means described in the afore-
mentioned EP-A-266,199, but in very many cases this level
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 1-12%,
preferably from 2-6% by weight, based on the total non-
aqueous composition.
The antifoaminq aqentIn view of the foaming behaviour of compositions according
to the invention, good results with respect to foam
reduction were obtained when using a combination of a
hydrocarbon wax and an alkyl phosphate as an anti-foaming
agent. It appeared that good defoaming characteristics can
be obtained after both separate and combined addition of
these compounds to a composition of the invention.
Alternatively, silicone oil based compositions containing
high and low viscosity oil, particularly high-viscosity
silicone oil with a viscosity greater than lOOOO Mp.s at
25C and a shear rate of 21 S-l, may be effectively used as
antifoaming agents.
~ W094/~009 21 5 9 6 0 7 PCT~4/00822
17
Miscellaneous other inqredients
Other ingredients which may be present in compositions of
the invention comprise those remaining ingredients which
may be used in liquid cleaning products. Examples are
fabric conditioning agents, enzymes, perfumes (including
deoperfumes), microbiocides, coloring 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 may be used in non-aqueous liquids according
to the present invention include proteolytic enzymes,
amylolytic enzymes and lipolytic enzymes (lipolases).
Various types of proteolytic enzymes and amylolytic enzymes
are known in the art and are commercially available. They
may be incorporated for instance as "prills", "marumes" or
suspensions.
The fluorescent agents which may be used in the non-aqueous
liquid detergent 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 composition of the
invention is generally from 0.02-2% by weight.
When it is desired to include anti-redeposition agents in a
non-aqueous liquid of the invention, 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
W094l~009 ~ 7 PCT~4/00822
18
composition. Preferred antiredeposition agents include
carboxy derivatives of sugars celluloses, e.g. sodium
carboxymethyl cellulose, anionic polyelectrolytes,
especially polymeric aliphatic carboxylates, or organic
phosphonates.
Use
Compositions according to the present invention may be used
for several detergency purposes, for example the cleaning
lo of surfaces and the washing of fabrics. For the washing of
fabrics, preferably an aqueous liquor containing from 0.1
to 10% by weight, more preferably 0.2 to 2~ by weight, of
the non-aqueous detergent composition of the invention is
used.
Processinq
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 non-aqueous 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 minimize 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 ~m, preferably 0.5 to 50 ~m, ideally 1 to 10 ~m, as
calculated by the D3 2 measure. 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 particle size distribution in
the final non-aqueous liquid product. Of course,
particulate material already having the desired particle
~ W094/~009 ~ 2 ~ 5 9 6 D 7 PCT~4/00822
19
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 liber~ation 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 the 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 is further illustrated by the following non-
limiting Examples, in which parts and percentages are by
weight unless otherwise stated. In the Examples the fol-
lowing abbreviations are used:
Vista Novel 1012.62: Nonionic surfactant, C10 5 ethoxylated
alcohol containing on average 6 EO
groups per molecule, ex Vista
Chemical
W094/~009 PCT~4/00822
~l~ 9G~7 20
Synperonic A3 : Nonionic surfactant, C11 ethoxylated
alcohol containing on average 3 EO
groups per molecule, ex ICI
Marlon AS-3 : The acid form of C12 alkyl benzene
sulphonic acid, ex Huls
Alfl6/Wax 2:1 : Defoaming agent consistin~ of alkyl
phosphate and hydrocarbon wax, in a
weight ratio of 2.1, ex Harcros/Ter
Hell
10 MgO : Magnesium oxide, ex Merck
SCMC : Sodium Carboxy methyl cellulose, ex
AKZO
Sokalan CP7 : Acrylic acid/maleic acid copolymer in
the sodium salt form, ex BASF
15 CaO : Calcium oxide, ex 8aker Chemical Co.
Crystalline SMS : crystalline sodium metasilicate, con-
taining at most 4% of water, Simet AG,
ex Rhone Poulenc
Amorphous SMS : amorphous sodium metasilicate, con-
taining about 2-3% by weight of water,
Vegomet, ex Montedison
Sypernat D17 : HM silica, ex Degussa
~ W094/~009 PCT~4/00822
21 _ 2I 596~ 7
Comparative Example A, Examples 1-3
The following non-aqueous detergent compositions (see
Table 1) were prepared by mixing the ingredients in the
order stated. It can be noted that the total solid phase
level was slightly reduced when more HM silica (i.e.
Sypernat D17) was included in the liquid compo~ition.
This is caused by the significantly lower density, and
consequently higher specific volume of the Sypernat Dl7 as
compared to crystalline sodium metasilicate. Sypernat D17
has a density of about 150 kg/m3, whereas the density of
the crystalline applied SMS is roughly 1200 kg/m3.
The ingredients were milled to give a mean particle size of
8 ~m (by the D3 2 measure). The tendency of the composition
to give clear layer separation was determined by filling a
500 ml tall polyethylene closable container with the
composition, allowing it to stand without agitation for 4
weeks at 37C and then measuring the height of any visible
distinct upper layer. As can be noticed, this measure of
the stability of each composition is shown in Table 1.
The viscosities, as measured after one week using a Haake
rotoviscometer at a shear rate of 21 s-1 at 25C after 5
minutes, of each composition are also given.
W094/23009 215 9 6 07 22 PCT~4/00822 ~
TABLE 1
EXAMPLE No: A 1 2 3
~wt %wt %wt%wt
Vista Novel 1012.6220.020.5 21.021.5
Synperonic A3 20 ~0 20.5 2~1.021.5
Alf-16/Wax 2:1 ~ .5 1.5 1.51.5
Marlon AS3 3.0 3.0 3.03.0
MgO 0.17 0.17 0.170.17
10 Crystalline SMS 46.03 44.03 42.0340.03
SCMC 1.5 1.5 1.51.5
Sokalan CP-7 5.0 5.0 5.05.0
CaO 1.0 1.0 1.01.0
Minor ingredients 1.8 1.8 1.81.8
15 Sipernat D17 0.0 1.0 2.03.0
Clear layer seP. (mm)
After 4 weeks, at 37C 18 8 6 3.5
Viscosity ( mPa.s)
(measured at 21 S-l)17001693 19841836
~ W094/23009 2 ~ 5 9 fi ~ ~ PCT~4/00822
23
These results clearly show that the incorporation of
hydrophobically modified silica increases the stability of
non-aqueous liquid detergent formulations containing
crystalline sodium metasilicate, without an unacceptable
rise in the viscosity of such formulations.
Comparative ExamPle B, Example 4
In a similar manner to Examples A, 1-3, the following
compositions were prepared. It can be seen from Table 2
that these compositions contain amorphous instead of
crystalline sodium metasilicate.
Thereafter, their stability as measured by their tendency
to give clear layer separation and their viscosity were
tested using the procedure described in Examples A, 1-3.
The test results are shown in Table 2.
W094/~009 PCT~4/00822
2~ 9 6~ 24
TABLE 2
EXAMPLE No: B 4
%wt %wt
Vista Novel 1012.6220.0 21.0
Synperonic A3 20.0 21.0
Alf-16/Wax 2:1 1.5 1.5
Marlon AS3 3.0 3.0
MgO 0.17 0.17
Amorphous SMS 46.03 42.03
SCMC 1.5 1.5
Sokalan CP-7 5.0 5.0
CaO 1.0 1.0
Minor ingredients 1.8 1.8
Sipernat D17 0.0 1.0
Clear laver se~. (mm)
After 4 weeks, at 37C11 6
Viscosity ( mPa.s)
(measured at 21 S-1)1260 1663
It can be seen that in this case a lower viscosity of the
non-aqueous liquid product was found than when crystalline
sodium metasilicate is applied.
Furthermore, these results clearly indicate that a
significant stability improvement (albeit slightly less
pronounced than the improvement found in Examples A, 1-3),
can also be obtained when incorporating HM silica in a non-
aqueous liquid detergent composition containing amorphous
sodium metasilicate.
