Note: Descriptions are shown in the official language in which they were submitted.
1 330645
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LIOUID DEq~ERGENT COMPOSITIONS
The present invention is concerned with liquid
detergent compositions of the kind in which particles of
solid material can be suspended by a structur~e formed
from detergent active material, the active structure
existing as a separate phase dispersed within
predominantly aqueous phase. This aqueous phase usually
contains dissolved electrolyte.
Three common product forms of this type are liquids
for heavy duty fabrics washing and liquid abrasive and
general purpose cleaners. In the first class, the
suspended solid can be substantially the same as the
dissolved electrolyte, being an excess of same beyond
the solubility limit. This solid is usually present as
a detergency builder, i.e. to counteract the effects of
calcium ion water hardness in the wash. In addition, it
may be desirable to suspend substantially insoluble
particles of bleach, for example diperoxydodecandioic
acid (DPDA). In the second class, the suspended solid
is usually a particulate abrasive, insoluble in the
system. In that case the electrolyte is a different,
water soluble material, present to contribute to
structuring of the active material in the dispersed
phase. In certain cases, the ahrasive can however
comprise partially soluble salts which dissolve when
the product is diluted. In the third class, the
structure is usually used for thickening products
to give consumer-preferred flow properties, and some-
times to suspend pigment particles. Compositions of the
first kind are described, for example, in our patent
specification EP-A-38,101 whilst examples of those in
the second category are described in our specification
EP-A-104,452. Those in the third category are, for
example, described in US 4,244,840.
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The dispersed structuring phase in these liquids is
generally believed to consist of an onion-like
configuration comprising concentric bilayers of
detergent active molecules, between which is trapped
water (agueous phase). These configurations of active
material are sometimes referred to as lamellar droplets.
It is believed that the close-packing of these droplets
enables the solid materials to be kept in suspension.
The lamellar droplets are themselves a sub-set of
I lamellar structures which are capable of being formed
¦ in detergent active/aqueous electrolyte systems.
Lamellar systems in general, are a category of
structures which can exist in detergent liquids. The
degree of ordering of liquid detergent structures, from
simple spherical micelles, through disc and rod-shaped
micelles to lamellar droplets and beyond progresses with
increasing concentrations of the actives and
electrolyte, as is well known, for example from the
reference H A Barnes, 'Detergents' Ch. 2 in K Walters
(Ed.), 'Rheometry:Industrial Applications', J Wiley &
Sons, Letchworth 1980. The present invention is
concerned with all such structured systems which are
capable of suspending parti¢ulate solids, but especially
those of the lamellar droplet kind.
The present invention solves a problem of introducing
functional polymer ingredients into aqueous structured
liquids. Functional polymer ingredients are those
'` 30 polymers which have a beneficial effect in use. The
definition does not include those polymers, the sole
function of which is to modify the rheology of the
i product. A very common type of functional polymer
;~ ingredient is a polymer builder. Functional polymer
ingredients may also serve the wetting properties of
liquid abrasive cleaners.
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1 330645
CA 8 718 217 claims and discloses use of certain polymers
having a molecular weight of at least 1000 for reducing the
viscosity of concentrated structured aqueous liquid
detergents. Such viscosity reducing polymers may or may
not also be functional.
CA 587 957 relates to use of polyacrylates or poly(meth)-
acrylates having molecular weights from 500 to 3000 for
improving the wetting properties of a Gertain class of
liquid abrasive cleaners.
Polymers have also been used for viscosity control in
slurries intended for spray_drying, for example as
described in specification EP-A-24,711, published
March 11, 1981. ~owever, such slurries have no requirement
of stability and so there is no difficulty with how the
polymer should be incorporated.
Further, it is known that incorporation of 5~ or more of
fabric softening clays, (e.g. bentonites) in liquids can
give rise to unacceptably high viscosity. One approach to
mitigate this disadvantage has been to also incorporate a
small amount of a low molecular weight polyacrylate. This
is described in UK patent specification GB-A-2,168,717,
published June 25, 1986.
Surprisingly we have now found that a functional polymer
ingredient can be incorporated up to relatively high
levels, without unduly affecting viscosity and without
destabilising the liquid, if the ingredient has an average
molecular weight below 2000, provided that when the
composition comprises:
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(a) at least 15~ by weight of the detergent active
material and from 1 to 30% by weight of a
salting-out electrolyte; or
~b) contains 5% or more of a swelling clay;
then the average molecular weight of the polymer
ingredient is less than 1000; and
when the functional polymer material comprises 0.5%
by weight or less, relative to the total
composition, of an acrylate or methacrylate polymer
having a molecular weight of 500 or greater, the
detergent active material comprises a synthetic
anionic surfactant and a soap and the composition
is free from pentasodium triphosphate;
then the composition is also substantially free
from insoluble abrasive;
said composition yielding no more than 2% by volume
phase separation upon storage at 25C for 21 days.
' -
i 25 Suitable function polymer ingredients include
polyethylene glycols~ Dextran, Dextran sulphonates,
polyacrylates, polymethacrylates and
~3 polyacrylate/maleic acid co-polymers.
Depending on the other components of the composition
and the type and molecular weight of the particular
,i polymer, it may be included at typically from 0.5% to
12.5% by weight of the total composition, for example
from 1% to 10%. Most preferred are those functional
polymer materials having an average molecular weight of
1000 or less.
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The detergent active material may be selected from
one or more of anionic, cationic, nonionic, zwitterionic
and amphoteric surfactants, and mixtures thereof,
provided the material forms a structuring system in the
liquid. Most preferably, the detergent active material
comprises
(a) a nonionic surfactant and/or a polyalkoxylated
anionic surfactant; and
(b) a non-polyalkoxylated anionic surfactant.
Suitable nonionic surfactants which may be used include
in particular the reaction products of compounds having
a hydrophobic group and a reactive hydrogen atom, for
example aliphatic alcohols, acids, amides or alkyl
phenols with alkylene oxides, especially ethylene oxide
either alone or with propylene oxide. Specific
nonionic detergent compounds are alkyl (C6 - C22)
phenols-ethylene oxide condensates, the condensation
products of aliphatic (Cg-Clg) prima~ or secondary
linear or branched alcohols with ethylene oxide, and
products made by condensation of ethylene oxide with
the reaction products of propylene oxide and
ethylenediamine. Other so-called nonionic detergent
compounds include long chain tertiary amine oxides, long
chain tertiary phosphine oxides and dialkyl sulphoxides.
The anionic detergent surfactants are usually
water-soluble alkali metal salts of organic sulphates
and sulphonates having alkyl radicals containing from
¦ about 8 to about 22 carbon atoms, the term alkyl being
I used to include the alkyl portion of higher acyl
1 35 radicals. Examples of suitable synthetic anionic
~ detergent compounds are sodium and potassium alkyl
¦ sulphates, especially those obtained by sulphating
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higher (C8 -C18) alcohols produced for example from
tallow or coconut oil, sodium and potassium alkyl
(Cg-C20) benzene sulphonates, particularly sodium linear
secondary alkyl (C10 -C15) benzene sulphonates; sodium
alkyl glyceryl ether sulphates, especially those ethers
of the higher alcohols derived from tallow o~ coconut
oil and synthetic alcohols derived from petroleum;
sodium coconut oil fatty monoglyceride sulphates and
sulphonates; sodium and potassium salts of sulphuric
acid esters of higher (C8-C18) fatty alcohol-alkylene
oxide, particularly ethylene oxide, reaction products;
the ~eaction products of fatty acids such as coconut
fatty acids esterified with isethionic acid and
neutralised with sodium hydroxide; sodium and potassium
salts of fatty acid amides of methyl taurine; alkane
monosulphonates such as those derived by reacting
alpha-olefins (C8 - c20) with sodium bisulphite
and those derived from reacting paraffins with SO2 and
C12 and then hydrolysing with a base to produce a random
sulphonate; and olefin sulphonates, which term is used
to describe the material made by reacting olefins,
particularly C10 - C20 alpha-olefins, with S03 and then
neutralising and hydrolysing the reaction product. The
preferred anionic detergent compounds are sodium (Cll -
Cls) alkyl benzene sulphonates and sodium (C16 - Clg)
alkyl sulphates. The total amount of surfactant material
will typically be from 10-50%, preferably from 15 to 4Q~
and most preferably from 20 to 30~ by weight of the
total composition.
The compositions preferably will contain a salting-out
electrolyte. This has the meaning ascribed to it in
specification EP-A-79j646. Optionally, some salting-in
electrolyte (as defined in the latter specification) may
¦ also be included, provided if of a kind and in an amount
compatible with the other components and the composition
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7 1 3 3 0 6 4 5 C 3277 (R)
is still in accordance with the definition of the
invention claimed herein. Some or all of the
electrolyte (whether salting-in or salting-out ) may
have detergency builder properties. In any event, it is
preferred that compositions according to the present
i~vention include detergency builder materiai, some or
all of which may be electrolyte. The builder material
is any capable of reducing the level,of free calcium
ions in the wash liquor and will preferably provide the
composition with other beneficial properties such as the
generation of an alkaline pH, the suspension of soil
removed from the fabric and the dispersion of the fabric
softening clay material. Typically the total amount of
electrolyte will be from 1 to 60%, preferably from 10 to
50%, most preferably from 20 to 45% by weight of the
total composition.
The compositions of the present invention have solid
suspending capability, and include those compositions
which actually contain particulate solids in suspension.
Such solids may be undissolved electrolyte or a
water-soluble or water-insoluble detergency builder
(whether or not the builder is also an electrolyte),
and~or a water-soluble or water-insoluble abrasive
(provided allowed according to the definition of the
present invention).
Examples of phosphorus-containing inorganic
detergency 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.
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1 330645
Examples of non-phosphorus-containing inorganic detergency
builders, when present, include water-soluble alkali metal
carbonates, bicarbonates, silicates and crystalline and
amorphous alumino silicates. Specific examples include
sodium carbonate (with or without calcite seeds), potassium
carbonate, sodium and potassium bicarbonate, silicates and
zeolites.
~xamples of organic detergency builders, when present,
include the alkaline metal, ammonium and substituted
ammonium polyacetates, carboxylates, polycarboxylates,
polyacetyl carboxylates and polyhydroxsulphonates.
Specific examples include sodium, potassium, lithium,
ammonium and substituted ammonium salts of
ethylenediaminetetraacetic acid, tartrate mono succinate,
tartrate di succinate, nitrilotriacetic acid, oxydisuccinic
acid, melitic acid, benzene polycarboxylic acids and citric
acid.
In the context of organic builders, it is also possible to
incorporate a viscosity reducing polymer according to our
aforementioned European patent application No. 301 883,
published February 1, 1989. Such polymers are
substantially totally soluble in the composition. It is
also possible to incorporate polymer ingredients which are
only partly dissolved, as related in our European patent
application No. 301 882, February 1, 1989.
The use of only partly dissolved polymers allows a
viscosity reduction (due to the polymer which is dissolved)
whilst incorporating a sufficiently high amount to achieve
a secondary benefit, especially building, because the part
which is not dissolved does not bring about the instability
that would occur if substantially all were dissolved.
Examples of partly dissolved polymers include many of the
polymer and co-polymer salts already knovn as
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detergency builders. For example, may be used
(including building an~ non-building polymers)
polyethylene glycols, polyacrylates with molecular
weights of at least 2000, polymaleates, polysugars,
polysugarsulphonates and co-polymers of any of these.
Preferably, the partly dissolved polymer comprises a
co-polymer which includes an alkali metal sa~t of a
polyacrylic, polymethacrylic or maleic acid or
anhydride. Preferably, compositions with these
co-polymers have a pH of above 8Ø In general, the
amount of such viscosity reducing polymer can vary
widely according to the formulation of the rest of the
composition. However, typical amounts are from 0.5 to
4.5~ by weight.
The optional polymer which is substantially totally
soluble in the aqueous phase must have an electrolyte
resistance of more than 5 grams sodium nitrilotriacetate
in lOOml of a 5% by weight aqueous solution of the
polymer, said second polymer also having a vapour
pressure in 20% aqueous colution, equal to or less than
the vapour pressure of a reference 2% by weight or
greater aqueous solution of polyethylane glycol having
an average molecular weight of 6000; said second polymer
having a molecular weight of at least 1000.
The incorporation of the soluble polymer permits
formulation with improved stability at the same
viscosity (relative to the composition without the
soluble polymer) or lower viscosity with the same
stability. The soluble polymer can also reduce
viscosity drift, even when it also brings about a
viscosity reduction.
It is especially preferred to incorporate the soluble
polymer together with a partly dissolved polymer which
has a large insoluble component, although the latter may
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I 330645
C 3277 (R)
be used without the former. That is because the
building capacity of the partly dissolved polymer will
be good (since relatively high quantities can be stably
incorporated), the viscosity reduction will not be
optimum (since little will be dissolved). Thus, the
soluble polymer can usefully function to reduce the
viscosity further, to an ideal level.
The soluble polymer can, for example! be incorporated at
from 0.05 to 20% by weight, although usually, from 0.1
to 2.5% by weight of the total composition is
sufficient, and especially from 0.2 to 1.5% by weight.
Levels above these may cause instability. A large
number of different polymer may be used as such a
soluble polymer, provided the electrolyte resistance and
¦ vapour pressure requirements are met. The former is
¦ measured as the amount of sodium nitrilotriacetate
(NaNTA) solution necessary to reach the cloud point of
lOOml of a 5% solution of the polymer in water at 25{C,
with the system adjusted to neutral p~, i.e. about 7.
This is preferably effected using sodium hydroxide.
~ost preferably, the electrolyte resistance is lOg
NaNTA, especially 15g. The latter indicates a vapour
pressure low enough to have sufficient water binding
rapability, as generally explained in the applicant's
specification GB-A-2 053 249. Preferably, the
measurement is effected with a reference solution at 10%
by weight aqueous concentration, especially 18~.
Typical classes of polymers which may be used as the
soluble polymer, provided they meet the above
requirements, include any of those specified above as
examples of the functional polymer materials, but having
instead, an average molecular weight of at least 2000.
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11 C 3277 (R)
The soluble polymer must have an average molecular
weight of at least 1000 but a minimum average molecular
weight of 2000 is preferred.
Compositions of the invention preferably have a
viscosity at 21s~l of less than 1,500 mPas, more
preferred less than 1,000 mPas. The pH of the
compositions is preferably from 7.5 to 12.5.
Apart from the ingredients already mentioned, a
number of optional ingredients may also be present, for
example lather boosters such as alkanolamides,
particularly the monoethanolamides derived from palm
kernel fatty acids and coconut fatty acids, lather
depressants, oxygen-releasing bleaching agents such as
sodium perborate and sodium percarbonate, peracid bleach
precursors, chlorine-releasing bleaching agents such as
tricloroisocyanuric acid, inorganic salts such as sodium
sulphate, and, usually present in very minor amounts,
fluorescent agents, perfumes, enzymes such as proteases
and amylases, germicides and colourants.
The invention will now be illustrated by the following
non-limiting examples.
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Table 1 Composition of the reference sample
1 5 Component Composition (~ w/w~
NaLAS (1) 10.4
j Synperonic A7 t2) 6.7
! NaCl 4.6
Water up to 1
~ 10 Polymer if added, on top of
¦ formulation
(1) Sodium dodecyl benzene sulphonate
(2) C12-13 fatty alcohol alkoxylated with an average of
~ 15 7 moles of ethylene oxide per molecule.
¦ Table 2 Product properties of composition of Table 1
with added Poly ethylene glycol. Variation in
¦ molecular weight.
~ 20
¦ Polymer Product
~ Mol.weiqht % Stability Vicosity (mPas)**
¦ - 0 Stable1060
¦ 25600 4.8 Stable990
1,000 4.8 Stable760
2,000 4.8 Unstable 120
4,000 4.8 Unstable 480
6,000 4.8 Unstable 440
3010,000 4.8 Unstable 190
* Stable means no more phase separation than 2% by
volume after two months storage at room temperatur~.
** measured at a sheàr rate of 21s-1
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13 C 3277 (R)
Table 3 Product properties of compositions of Table 1
with added Poly ethylene glycol. Variation in
level and mol. weight.
Polymer Product
Mol.weiaht % Stability Viscosity (mPas) **
- 0 Stable 940
_______________________________________________________
600 3.8 Stable 930
600 7.6 Stable 1020
600 ll.S 5table 770
15600 15 3 Stable 560
1,000 2.9 Stable 800
1,000 5.7 Stable 820
1,000 8.6 Stable 590
201,00011.5 Stable 380
____________________________________~___________________
2,000 1.0 Stable 700
2,000 1.9 Stable 540
2,000 2.9 Stable 280
252,000 3.8 Unstable 110
¦ 2,000 4.8 Unstable 120
________________________________________________________ ,
1 4,000 1.0 Stable 210
¦ 4,000 1.9 Unstable 300
1 30 ----------------____________________
1 6,000 0.5 Stable 340
6,000 1.0 Unstable 170
6,000 1.4 Unstable 370
____________________,___________________________________
10,000 0.5 Stable 210
10,000 1.0 Unstable 430
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14 C 3277 (R)
Table 4 Product properties of compositions of
Table 1 with added Sodium poly acrylate.
Variation in level and mol. weight.
Polymer Product
Mol. weight % StabilitY *** Viscosity (mPas~**
- 0 Stable 710
1,200 0 Stable 730
1,200 0.50 Stable 520
1,200 1.00 Stable 450
______________________________________________________ , .
2, 500 0 Stable 630
2, 500 0 . 50 Stable 410
_____________________________________________________
4, 000 0 Stable 150
4,000 1.00 Unstable 130
------_____________________________
8,000 0 Stable 380
8,000 0.50 Stable 130
8,000 1.00 Unstable 110
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*** Stable means no more phase separation than 2% by
volume after 21 days storage at 25"C.
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C 3277 (R)
Table 5 Composition of reference sample 2.
Component Composition (%w/w)
NaLAS (1) 7.2
Synperonic A3 (3) . 2.4
10 LES (4) 2.4
Zeolite 4A (anhydrous) 20.0
Citric acid 1.5
Glycerol 8.0
Borax 5.7
15 NaOH to adjust the pH to 8.5
Polymer var
see Table 6
Water up to 100
(1) Sodium dodecyl benzene sulphonate.
(3) C12-13 fatty alcohol alkoxylated with an average of
3 moles of ethylene oxide per molecule.
(4) Lauryl Ether Sulphate (Approx 3EO).
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Table 6 Product properties of composition of Table 5
with added Sodium Poly Acrylate. Variation in
level and mol. weight.
Polymer Product
Mol. weiqht % Stabilitv *** Viscositv (mPas) **
- 0 Stable 1250
________________________________________________________
1,200 0.2 Stable 1190
1,200 0.5 Stable 1030
_________~______________________________________________
2,500 0.2 Stable 1250
2,500 0.5 Unstable 500
_______________________________________________________
4,000 0.2 Stable 360
4,000 0.5 Unstable 100
______________ _______________________________________
** At 21s-1
*** Stable means no more phase separation than 2% by
volume after 21 days storage at 25 C.
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