Note: Descriptions are shown in the official language in which they were submitted.
~ W O 94/03580 21~1~ 5~:2 ~ PC~r/GB93/01636
DETERGENT COMPOSITIONS
Thls invention relates to detergent compositions and in particular
to non-aqueous laundry liquid detergent compositions.
Deter8ent compositions are known which comprise a suspension of a
builder and opt;on~ly other solids in an organic liquid which
comprises a surfactant. Non-aqueous compositions of this
type, of good~t~b;lity, are described in European Patent
Specifications Nos EP 0030096 B and EP 0120659 B. Such compositions
may contain phosphate b~ ers, for example alkali metal condensed
phosphates, for example sodium tripolyphosphate.
When a non aqueous composition comprising a condensed phosphate
builder is contacted with water it is possible with certain models of
washing ~ chine if used with certain washing programmes to form a
solid deposit comprising the builder which is slow to dissolve. If
access of water $o the deposit is limited the deposit may not dissolve
during the w~sh;ng process,
In some cases detergents are placed in containers which are
introduced into the ~ sh;ng zone. If the con~ainer has restricted
access solid deposits may be left in it especially if it was not dry
when detergent was placed in it.
We have now found that if a minor quantity of a water soluble salt
of a hydro~ycarboxylic acid, particularly of tartaric or citric acid,
is included in the composition this problem with condensed phosphate
builders can be substantially mitigated.
This invention accordingly provides a substantially non-aqueous
liquid laundry detergent composition which comprises a surfactant, a
condensed phosphate b~ er and a water soluble salt of a hydroxy-
carboxylic acid cont~in;ng 1 to 6 -COO~ groups and 1 to 5 -OH groups.
or a water soluble salt of such an acid.
By ~substantially non-aqueous n we mean that the amount of water in
the composition is sufficiently small that the tendency of the
condensed phosphate builder to hydrolyse and thus to cause the
viscosity of the detergent formulation to increase or the formulation
to gel during storage prior to use is overcome. In practice, it is
free water i.e. water that is not ch~ c~lly bound as in water of
crystallisation, in the formulation that is problematical and the
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amount of $ree water will usually be kept to less than ZZ, and very
desirably less than l~, by weight of the composition. Small
quantities of free water are typically present in various components
of the formulation e.g. non-ionic surfactants and polyethylene glycol,
and it is the concentration of water from such sources th~t should be
kept suitably low. Water of crys~llis~tion in material~s such as the
hydroxycarboxylic acid salt(s), as in sodium citrate dihydrate, is not
usually a problem.
The hydroxycarboxylic acid salt is desirably a salt of an acid
which contains a total of at least 3 hydrosyl and carboxyl groups.
Salts of tartaric and citric acids are particularly useful materials.
Mixtures of salts of these acids can be used if desired. The use of
salts of either or both of these acids forms a particularly
advantageous feature of this invention. The salt cation is desirably
an ammonium, substituted ammonium or alkali metal, particularly
sodium, salt. The salt is desirably present in an amount to give a
weight ratio of the condensed phosphate builder to the hydroxy-
carbosylic acid salt of 60:l to 5:l, and particularly 30:l to 7:l,
especially about 20:l. The amount of hydroxycarboxylic acid salt used
in compositions of this invention is relatively small. At relatively
high concentrations, hydroxycarboxylic acid salts can act as builders
in detergent formulations. In this invention, the amount used is
typically sufficiently small that the hydroxycarboxylic acid salt does
not provide significant effect as a builder over and sbove that
provided by the condensed phosphate builder.
The composition is preferably ~lk~line in reaction i.e.
when added to water, as in use, the laundry water is rendered
alkaline. It is preferred that normally acidic substances when
present in the composition are in a form neutralised with alkali,
particularly cont~;nin~ one or more of ammonium, substituted ammonium
or, and preferably, alkali metal ions. Specific additives can be
included to control the ~lk~linity of the laundry water in use, such
as sodium disiiicate or, especially if somewhat less ~lk~line
conditions are desired, sodium bicarbonate.
The condensed phosphate builder may be an alkali metal, preferably
a potassium or sodium salt of a condensed phosphate. Linear condensed
phosphates are better builders than cyclic materials and are thus
W 0 94/~358~ 2~ 52 ~ P~r/GB93/UI636
preferred._ Typically the condensed phosphate will be a di-phosphate
~pyrophosphate) for example sodium pyrophosphate Na4P207, or
tri-phosphate (tripolyphosphate), for example potassium
tripolyphosphate, or, and particularly desirably, sodium
~ripolyphosph~ate. The total builder content of the composition
~including the condensed phosphate b~;ld~r) will generally be from 25
to 60Z by weig~t. Other b~ ers e.g. sodium carbonate and sodium
bicarbonate, can be included if desired, but the amounts of such
builders, when present, are usually relatively small for example from
1 to lOZ by weight of the composition.
The composition can include a bleach such as a perborate or
percarbonate e.g. as an alkali metal, particularly sodium, salt.
When used, the amount o the bleach will typically be from 1 to 25Z,
particularly 2 to 20~, more particularly 5 to 20~, and especially
about 10 to about l5Z, by weight of the composition. Further, a
bleach activator such as tetra-acetyl ethylene ~;~mine~ can also be
included in the composition.
The surfactant will typically include at least one non-ionic
surfactant. Suitable non-ionic surfactants include alkylene oxide
derivatives, particularly where the alkylene oxide is ethylene and/or
propylene oxide, especially ethylene oxide. Particularly suitably
materials include reaction products of an amine, alkyl phenol or
alkanol with ethylene andlor propylene oxide, especially ethylene
oxide. When amine reaction products are used, the amine will usually
be an alkyl amine in which the alkyl group can be straight or branched
chain and can contain from 6 to 20, particularly 10 to 16, carbon
atoms. When alkyl phenol reaction products are used, the alkyl group
can be straight or branched chain and can contain from 6 to 20,
particularly 6 to 12, carbon atoms. When alkanol reaction products
are used, the alkanol is preferably a primary or secondary alkanol
having a linear or mono brnnr~ed alkyl chain and the alkanol can
contain 6 to 20, preferably 10 to 16, carbon atoms. Suitably the
(poly)oxyalkyle~e chain in the ncn-ionic surfactant has from 1 to iO,
preferably 3 to 8, alkylene oxide residues. Of course, the number of
alkylene oxide residues given is an average value. The amount of
non-ionic surfactant is typically from 5 to 25~, particularly 7 to
20~, by weight of the composition.
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Although non-ionic surfactants are generally the preferred
surfactants in this invention, the surfactant may alternatively be or
include one or more anionic or cationic surfactants. Such anionic or
cationic surfactants may be of known type for example the anionic
detergents may be soaps, alkylben~ene or olefin sulp~ohates, alcohol
sulphates or alcohol alkoxylate sulphates; the cat~o~ic surfactants
are suitably di-C10_22 and preferably di-Cl6_1g ar~yl, di-lower alkyl
ammonium salts or hydroxides for example chlorides or sulphates or for
example fabric softeners of the Cl0-l6 alkyl, di-lower alkyl (for
example methyl), substituted ethyl Ammnnium salts. The substituent on
the ethyl group msy be an -OOCR group where R is a C13_22 alkyl group,
and the anion of the salt may be a RS04- group where R is lower alkyl
for example methyl. The lower alkyl groups are suitably methyl
groups.
The composition desirably also includes a polyalkylene glycol, for
esample a polyethylene/polypropylene glycol or and particularly
advantageously a polyethylene glycol. This enhances the fluidity of
the compositions and, partlcularly where the polyalkylene glycol is a
polyethylene glycol, is readily biodegradable. The polyalkylene
glycol, particularly a polyethylene glycol, desirably has a molecular
weight of 100 to 1500 D, especially 100 to 500, and for example 150 to
400, D. Polyalkylene glycols, particularly polyethylene glycols, of
a~erage molecular weight lO0 to 400 and preferably 150 to 300 are
especially useful as they can act to reduce the pour point of the
liquid laundry detergent compositions thus making them more easily
usable in a cold environment. When present the polyalkylene glycol,
particularly polyethylene glycol is typlcally present as 5 to 55~,
particularly lO to 502 and especially 25 to 452, by weight of the
composition.
The composition may also contain additives conventionally found in
detergent compositions, for example fabric conditioners, anti-
redeposition sids such as carboxymethyl cellulose tsee below), pH
adjusters (see above), anti-corrGsion additives e.g. sodium disilicate
(which also acts as a pH adjuster), optical brighteners, sequestrants
e.g. ethylene ~;~m;n~ tetra-acetic acid, dyes, perfumes and/or
enzymes.
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The li~uid composition will generally take the form of a
dispersion of solid particles in a liquid medium.
Typically the solids will include the condensed phosphate builder,
other inorganic builders, when present, the hydroxycarboxylic acid
salt(s), the bleach, when present, and other solid minor components
not soluble in ~the liquid medium. Usually, the laundry liquid
composition will comprise 25 to 70Z and particularly 30 to 65Z, for
example 40 to 65Z, by weight of total solids. Desirably, to reduce
the tendency of the solid to separate from the liquid cnmponent, the
solids will be finely divided solids and in particularly the solids
have an average particle size of at most 10 ~m and very particularly
from 1.2 to 8 ~m. To avoid the composition having a 'gritty'
appearance or feel, the proportion of relatively large particles will
usually be kept small and, thus, it is very desirable that at least
90Z of the solid particles have a size of less than 10 ~m. Stated
partlcle sizes are the diameters of particles of equal volume.
Desirably, the particle size distribution is relatively narrow so that
average particle sizes e~pressed as number average or weight average
sizes are similar. Particle sizes can be measured, for e~ample, using
Coulter counters or laser particle size measuring equipment such as
that sold under the Malvern name.
Typically, the liquid medium will include the liquid surfactant
such as non-ionic surfactant(s), when present, the polyoxyalkylene
glycol, when present, other minor liquid components and solid
components solubie in the liquid medium. Corresponding to the solids
content of the laundry liquid composition, the liquid medium will
comprise 75 to 30Z and particularly 70 to 35Z, for example 60 to 35Z,
by weight of the composition.
Cationic and anionic surfactants when present will, depending on
their properties either form part of the solids or will be wholly or
partly liquid or dissolved in the liquid medium.
The formulation can include anti-redeposition aids. These include
t polycarbo~ylic acids having at least 10, usually at least 100,
particl-lPl ry 150 to 2000 and especially 200 to 1000, COOH groups.
Carbo~ymethyl cellulose is a suitable anti-redeposition aid.
The composition suitably has a pour point (ASTM D 97-66, 1971) of
less than 10C and particularly less than 5C. The pour point may be
W O 94/03580 ` PC~r~GB93/01636 -
2141~52
.,
adjusted by- varying the liquid phase composition, for example, by
including surfactants andlor poLyethylene glycol of low pour point.
In compositions according to the invention the dispersion of the
solids in the non-ionic surfactant is remarkably stable especially if
the particle size of the solids is at most 10 ~m. If the solids
separate at all then the resulting phase is usu~lly loosely
flocculated and is readily redispersible while i~ the relative amounts
of the solids, polyethylene glycol and surfa~t~nt in the composition
are correctly chosen there is little phase separation as the liquid
fills the space between the loosely packed solid particles.
An especially useful substantially non-aqueous liquid laundry
detergent composition which forms a particular feature of the invention
is one which comprises:
from 25 to 60Z by weight of condensed phosphate builder;
from 5 to 25% by weight of at least one non-ionic surfactant;
from 5 to 55Z by weight of polyethylene glycol having a molecular
weight of from 100 to 500;
optionally
from 1 to 25% by weight of sodium perborate or percarbonate
ble~ch; and
a water soluble ammonium, substituted ammonium and/or alkali metal
salt of tartaric and/or citric acid in an amount to give a weight
ratio of condensed phosphate builder to acid or salt of from 60:1
to 10:1,
and wherein the composition comprises from 65 to 40% by weight of
solid particles having an average size of less than 10 ~m
dispersed in a liquid medium which is correspon~ingly from 35 to
60% by weight of the cQmposition.
Compositions according to the invention may suitably be made by a
process which comprises milling ingredients together for example by
bead m;ll;ng.
~ WO 94/03580 2 1 41 g s ? PC~rtGB93/0l636
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The invention is illustrated by the following Examples. All parts
and percentages are by weight and in the Examples weight percentages
are based on the total weight of the composition unless otherwise
specified.
. .
Materials
Tripolyphosphate
is sodium tripolyphosphate.
Sodium EDTAte
is the tetrasodium salt of ethylene ~;~m;ne tetra-acetic acid.
Optical brightener
is "Leucophor DUK" optical brightener from Sandoz.
CMC is carboxymethyl cellulose sold as "Courlose" A610, degree of
substitution 0.5 to 0.7, molecular weight believed to be 60000
to 100000.
A3 is ~Synperonic~ A3 which is the product of condensing an
average of 3 moles ethylene oxide with a mixture of two parts
C13 primary alkanol to one part Cls pr;m~ry alkanol, both
having some 2-methyl br~nch;n~.
2Q 87K is "Synperonic~ 87K which is the product of condensing an
average of 7 moles of a mixture of 92~ ethylene oxide and 8
propylene oxide with a mixture of two parts C13 primary
alkanol to one part Cls primary alkanol, both having some
2-methyl br~nrh;ng.
PEG 200 is Polyethylene glycol of average molecular weight Z00 D
EXAMPLES 1 to 7
Liquid formulations A - ~ (Control sample Cl - formulation A and
Examples 1 to 7 - formulations B - H) were produced by m;~;ng together
the components in the amounts given in Table 1 below in a homogeniser
and then bead m; I 1 ;ng ~he mixtu 2S until the solids had an ~verage
particle size of 3 ~m.
W O 94/03580 PC~r/GB93/01636
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TABLE 1
Components by weight percent
Formulation A B C D E F G H
Example Cl 1 2 3 4 5 6 7
Tripolyphosphate41.5 41.0 40.5 39.5 37.~'41.0 40.5 39.5
Sodium citrate - O.5 1.0 2.0 4.0 - - -
Sodium tartrate - - - - -0.5 1.0 Z.0
Sodium disilicate 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0
Sodium EDTAte 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2
Optical brightener 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3
CMC 1.0 1.0 l.0 1.0 1.0 l.0 1.0 1.0
Titanium dioxide 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Sodium carbonate 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0
A3 2.5 2.5 2.5 ~.5 2.5 2.5 2.5 2.5
87~ 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5
PEG 200 39.75 39,75 39 75 39.75 39 75 39 75 39 75 39 75
The dispensability of each formulation was assessed by weighing
60g of the laundry liquid into a commercially available rectangular
plastic dosing device measuring ca. 6.5 x 5 x 3.5 cm which was placed
in the drum of a Philips 036 washing machine on top of 3.5 kg of
laundry (laboratory coats and towels). The machine was started on
programme No 5 which has a 27 minute wash cycle with cold water fill,
taking 10 minutes to reach the 40C wash temperature. 10 minutes
after the drum had started to roll the machine was stopped, drained
and the dosing device removed. The amount of any residues left in the
dosing device was recorded. This procedure was carried out at least 3
times for each formulation. The test results are set out in Table 2
below.
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_ g _
TABLE 2
Residues (g) after 10 mins Mean Std. Dev.
A 7.09, 2.24, 4.95 4.8 2.43
B 4.89, 9.36, 11.03 8.4 3.17
C 1.38,32.24*, 2.56 2.0 0.85
D nil, 2.46, nil, 25.35* 0.8 1.42
E nil, nil, 0.04 0.01 0.02
F 0.75, 3.07, nil 1.3 1.60
G nil, 8.88, nil 3.0 5.13
H nil, 0.17, nil 0.06 0.10
* On these occasions the dosing device was blocked by fabric falling
into it and these results were ignored in the calculation of the mean
and standard deviation.
The performance at 40C of 60 g of formulations A, D, E and H were
compared in wash tests using a Zanussi FL1030 washin~ machine and Tees
Valley Water (90 ppm Ca hardness) using standard detergency test
cloths from EMPA and Krefeld. The washing ch;ne was filled with
four test ~ieces ~10 x 10 cm) of each different type of test cloth
together with 2 kg of clean cloth as ballast for each wash. Each test
cloth was measured before and after washing in 10 different places to
assess the increase in reflectance of the cloth. The results are set
out in Table 3.
TABLE 3
KREFELD 10 CEMPA 101 KREFELD 20 CEMPA 104
Formulation A 26.5 33.0 27.0 35.1
Formulation D 29.3 31.9 22.5 33.6
Formulation E 23.6 30.1 16.2 31.0
Fonmulation ~ 27.3 33.5 20.8 32.1
The above results indicate that the optimum ratio of the condensed
phosphate builder to hydroxycarborylic acid salt is probably in the
range 40:1 to 20:1.
