Note: Descriptions are shown in the official language in which they were submitted.
~ 0381 c 789 (R)
The invention relates to liquid detergent compositions
which are suitable for fabric washing, and in particular to
such compositions containing phosphate detergency builders.
Aqueous built liquid detergent compositions are well
known in the art. Although they offer several advantages
over other forms of detergent compositions like powders,
such as improved solubility and easier dosing, their
formulation is very difficult, since they should be physical-
ly stable under a wide range of storage conditions, for
example from about -4C to 37C. Also they should have
satisfactory pouring properties despite containing relative-
ly high concentrations of detergent ingredients, especially
builder salts so that ideally they have performances
equivalent to the usual powdered detergent compositions.
The ~rior art mainly teaches the use of more water
soluble ingredients, such as tetrapotassium pyrophosphate,
usually with expensive stabilising agents, but even then
the amount which can be used is lower than would be
desired in comparison with powdered detergent compositions.
Although such prior liquid formulations may provide accept-
able compositions as far as their physical characteristics
are concerned, their detergency and other washing properties
tend to be u~satisfactory. F'or example, with the alkali
metal pyrophosphates there are cften deposits formed on the
clothes, especially when the products are used at excep-
tionally low product concentrations, or at high temperatures.
-- 2
11~0381
C 789 (R)
When attempts have been made to improve the detergency,
then the stability and pourability have become unsatisfactory.
In particular, it has not been possible to incorporate into
the liquid detergent compositions sufficiently high levels
of the conventional detergency builders such as sodium
tripolyphosphate without causing severe problems of
separation or solidification of the liquid compositions.
It has now been found, that homogeneous, clear,
built liquid detergent compositions can be obtained
by using certain mixtures of sodium tripolyphosphate and
sodium or potassium orthophosphate as builders, and using
a hydrotrope system which comprises at least two hydro-
troping agents 3 which will be defined hereinafter.
Insofar as the two detergency builder materials
function normally in different ways, i.e. by sodium
tripolyphosphate acting as a sequestrant detergency builder
and the alkali metal orthophosphate functioning as a
precipitant builder, it is somewhat surprising that a
mixture of the materials functions so effectively. In
particular, when sodium orthophosphate is used alone as
a detergency builder it tends to cause inorganic
deposition on the washed fabrics, which is accompanied
by soil red$position; but in the presence of the sodium
tripolyphosphate the soil redeposition is significantly
decreased whilst the detergency is apparently boosted.
Moreover, incomparison withthe use of sodiumtripoly~?hos-
~ 381 C 789 (R)
phate alone as detergency builder, the same amount of the
mixed sodium tripolyphosphate and alkali metal orthophos-
phate detergency builders shows improved detergency and
soil redeposition properties, especially in hard water.
There have in the past been many suggestions for using
mixed phosphate detergency builders, for example mixtures
of sodium pyrophosphate and sodium tripolyphosphate, in
liquid compositions, particularly those adapted for hard
surface cleaning. Moreover, it is well known that the
condensed phosphates such as sodium tripolyphosphate tend
to degrade in aqueous alkaline conditions at high
temperatures, which are often met during detergent
processing conditions, so as to form other phosphates; for
example sodium tripolyphosphate tends to break down to give
a mixture of sodium pyrophosphate and sodium orthophosphate.
However, to the Applicants' knowledge it has not been
proposed hitherto to use the specific mixtures of sodium
tripolyphosphate and alkali metal orthophosphate in the
proportions as set out below in homogeneous fabric washing
liquid detergent compositions according to the present
invention. The formation of the clear liquid detergent
compositions with much higher detergency builder levels
than has hi~herto been possible is particularly advanta-
geous. Apart from the consumer benefits of lower viscosity
and better storage properties than heterogeneous, suspended
liquid compositions~ they can generally be made more
easily.
-- 4 --
llQ~381 c 789 (R)
~he ratio of the sodium tripolyphosphate to the alkali
metal orthophosphate in the detergent composition is from
about 10:1 to about l:lO,particularly about 5:1 to about
1:2 parts by weight, preferably from about 4:1 to about
2:3, and especially from about 3:1 to about 1:1 parts by
weight. These ratios of sodium tripolyphosphate to the
alkali metal orthophosphates are chosen to give optimum
detergency building and other washing properties in
relation to the maximum amount of these ingredients which
can be tolerated in the liquid compositions without loss
of stability.
It will be appreciated that the actual amounts of
sodium tripolyphosphate and alkali metal orthophosphate
are chosen according to the overall phosphate detergency
builder level which is desired or permitted in the liquid
detergent compositions. However, it is normal to use a
total amount of sodium tripolyphosphate plus alkali metal
orthophosphate within the range of from about 6%to about
35% by weight of the composition, preferably from about
10% to about 25%, and especially about 15% to about 25%
by weight. It is also preferred that the individual
amount of each of the sodium tripolyphosphate and the
alkali metal orthophosphate should be at least about 4~,
and 2% respectively, the latter preferably at least about
4% by weight of the composition.
When higher levels of sodium tripolyphosphate are
used, i.e. above about 12% by weight of the composition,
it is advantageous to use as the sodium tripolyr)ho phate
-
110C~381
C 789 (R)
a type of material which hydrates rapidly, as this aids its
solubility, particularly for use in compositions containing
higher levels of sodium tripolyphosphate. Suitable types of
sodium tripolyphosphate are commercially available with a
high, i.e. greater than 50%, phase I content, and they may
also be partially or fully prehydrated. Processing
conditions, including mixing temperatures, are of course
adjusted according to the type of sodium tripolyphosphate
employed.
Apart from the mixed phosphate detergency builders,
the liquid detergent compositions of the invention contain
a detergent active compound, which may be an anionic,
nonionic, amphoteric or zwitterionic detergent active
compound or mixture thereof. Many suitable detergent active
compounds are commercially available and are fully described
in the literature, for example in 'tSurface Active Agents and
Detergents", Volumes I and II, by Schwartz, Perry arld Berch.
The preferred detergent compounds which can be used
are synthetic anionic compounds. These 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 used to
include the alkyl portion of higher acyl radicals. Examples
of suitable synthetic anionic detergent compounds are sodium
and potassium primary or secondary alkyl sulphates,
especially those obtained by sulphating the higher ~C8-C18)
alcohols produced by reducing the glycerides of tallow or
coconut oil; sodium and potassium alkyl (Cg-C20) belzene
110~381 c 789 (R)
sulphonates, particularly sodium linear secondary alkyl
(C10-Cl5) benzene sulphonates, sodium alkyl glyceryl ether
sulphates, especially those ethers of the higher alcohols
derived from tallow or coconut oil and synthetic alcohols
derived from petroleum; sodium coconut oil fatty ac:id mono-
glyceride sulphates and sulphonates; sodium and potassium
salts of sulphuric acid esters of higher (C9-C18) fatty
alcohol-alkylene oxide, particularly ethylene oxide, reaction
products; the reaction 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 primary and
secondary monosulphonates such as those derived by reacting
alpha-olefins (C8-C20) with sodium bisulphite and those
derived byreacting paraffins with S02 and Cl2 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 alpha-
olefins, with S03 and then neutralising and hydrolysing the
reaction product.
Although in general the sodium salts of the anionic
detergent compounds are cheaper, the potassium salts may
be used to advantage, particularly in compositions with
high levels of other sodium salts such as sodiu~ tripoly-
phosphate and sodium orthophosphate.
Of the anionic detergent compounds, alkali ~et<~l alkyl(C10-Cl5) benzene sulphates are particularly preferred,
both for ready availability and cheapness and al~o 1or
110~381 c 789 (R)
their advantageous solubility properties.
If desired, nonionic detergent active compounds may be
used as the sole detergent compounds, or preferably in
admixture with anionic detergent compounds, especially the
alkyl benzene sulphonates. Examples include the reaction
products of alkylene oxides, usually ethylene oxide, with
alkyl (C6-C22) phenols, generally 5 to 25 EO; i.e. 5 to 25
units of ethylene oxide per molecule; the condensation
products of aliphatic (C8-C18) primary or secondary
alcohols with ethylene oxide, generally 2 to 30 EO, e.g.
6-20 EO, and products made by condensation of ethylene
oxide with the reaction products of propylene oxide and
ethylenediamine. It is also possible to use such nonionics
which have been prepared by first ethoxylating and
subsequently propoxylating the hydroxyl-containing organic
radical, e.g. C8-C18 alcohols with EO and PO. Other so-
called nonionic detergent active compounds include long
chain tertiary amine oxides, long chain tertiary phosphine
oxides and dialkyl sulphoxides.
Mixtures of detergent active compounds, for example
mixed anlonic or mixed anionic and nonionic compounds may
be used in the detergent compositions, particularly to
impart thereto controlled low sudsing properties.
Mixtures of amine oxides and ethoxylated anionic compounds
can also be beneficial.
Amounts of amphoteric or zwitterionic deterger~t active
compounds can also be used in the liquid detergent
compositions of the invention but this is not n~rm.lly
1100381
desired due to their relatively high cost. If any
amphoteric or zwitterionic detergent active compounds are
used it is generally in small amounts in compositions
based on the much more commonly used anionic and/or nonionic
detergent active compounds.
The amount of the detergent active compound or com-
pounds used is generally in the range of from about 2% to
about 20%, preferably about 5% to about 15%, by weight of
the compositions, depending on the desired properties.
Lower levels of nonionic detergent compounds should be used
within this range, as they tend to form a separate liquid
phase if used at higher levels, that is over about 5% by
weight. The ratio of the total detergent active compounds
to the total of the amount of sodium tripolyphosphate and
alkali metal orthophosphate should generally be in the range
of from about 2:1 to about 1:5, preferably about 1:1 to
about 1:3 parts by weight.
In order to facilit~te the production of the homo-
geneous liquid detergent compositions with relatively high
levels of detergency builders present, it is preferred
to use potassium rather than sodium orthophosphate.
Potassium orthophosphate can be added as such, or ortho-
phosphoric acid may be neutralised by a potassium salt such
as potassium hydroxide during production of the compositions.
It should be understood that the term alkali metal ortho-
phosphate includes the mono-, di- and tri-orthophosphates.
Instead of the sodium tripolyphosphate the potassium salt
may be used, but this is more expensive.
g
1100381
It is essential to have a hydrotrope system in the
compositions, to reduce any tendency to separation into
different liquid phases. The hydrotrope system which has
been found effective for use in the homogeneous liquid
detergent compositions comprises a hydrotrope, selected
from the group consisting of alkalimetal or ammonium toluene-,
cumene- and exylene sulphonates, urea, lower aliphatic
alcohols such as ethanol which is commonly supplied as
industrial methylated spirit (IMS), and a hydrotrope selected
from the group consisting of lower (C8-C18) fatty acid
alkylolamides such as coconut ethanolamide, and readily
water-soluble soaps of C10-C22 fatty acids, including such
polymerized fatty acids, such as potassium coconut soap
and potassium oleate, potassium soap of dimerized oleic
acid and mixtures of these materials. The presence of
such soaps as hydrotropes is particularly beneficial in
homogeneous liquid compositions containing higher levels
of sodium tripolyphosphates, i.e. over about 15% by weight.
The fatty acid alkylolamides also functicn as lather boosters
and therefore should not normally be used in low sudsing
compositions.
The amount of each of the hydrotropes, constituting
the hydrotrope system is normally in the range from about
1% to about 15~, preferably about 5% to about 10% by weight
of the composition. It should be noted that an excess of
these hydrotropes can be deleterious just as well as too
little material, for optimum liquid compositions properties,
but satisfactory levels can be found readily within the
-- 10 --
1100381
range described.
It is desirable to include one or more anti-
deposition agents in the liquid detergent compositions of
the invention, to decrease any tendency to form inorganic
deposits on washed fabrics, especially under conditions of
use at low product concentration. Examples of preferred
anti-doposition agents are homo- and copolyacrylates, e.g.
sodium polyacrylate, the sodium salt of copolymethacrylamide
acrylic acid and sodium poly-alpha-hydroxyacrylate, salts
of copolymers of maleic anhydride with ethylene, methyl
vinyl ehter or styrene, especially 1:1 copolymers, optionally
with partial esterification of the carboxyl groups, and the
sodium salts of polymaleic acid and polyitaconic acid.
Such copolymers preferably have relatively low molecular
weights, e.g. in the range of about 2,000 to 50,000. The
maleic anhydride copolymers can also have some stabilising
properties especially when nonionic detergent compounds are
used. Other, less preferred, anti-deposition agents in-
clude phosphate esters of ethoxylated aliphatic alcohols,
polyethylene glycol phosphate esters, and certain phos-
phonates such as sodium ehtane-l-hydroxy-l, l-diphosphonate,
ethylenediamine tetramethylene phosphonate and sodium
2-phosphonobutane tricarboxylate. The most preferred
anti-deposition agent is sodium polyacrylate having a MW
of about 2,000 to about 30,000, e.g. about 15 to 25,000.
The amount of such anti-deposition agents is generally about
0.1% to 5.0%, preferably about 0.2% to about 2% by weight
of the compositions.
X~
1100381 c 789 (R)
It is also possible to include in the detergent
compositions of the invention minor amounts, for example up
to about 10% by weight, of other detergency builders, which
may be either so-called precipitant builders or sequestrant
builders. This may be of particular benefit where it is
desired to increase detergency whilst using particularly low
levels of the essential sodium tripolyphosphate and alkali
metal orthophosphate builders, so as to achieve particularly
low phosphorus contents in the detergent compositions for
environmental reasons. Examples of such other detergency
builders are amine carboxylates, such as sodium nitrilo-
triacetate. However, it is desirable to have no other
phosphate detergency builders present other than the sodium
tripolyphosphate and alkali metal orthophosphate, and
in particular it is desirable to exclude pyrophosphates
from the compositions as they tend to increase inorganic
deposition and soil redeposition. Some pyrophosphate may
be present for example as an impurity in the sodium tri-
polyphosphate, or it may be produced by hydrolysis of the
sodium tripolyphosphate during detergent processing
particularly under alkaline conditions at elevated
temperatures~ so low levels of sodium pyrophosphate may
be unavoidable, but it is preferred to have no more than
about 5%, especially less than about 2% by weight of pyro-
phosphate present in the compositions.
The liquid detergent compositions of the inventioncan contain any of the conventional additives in t~e
amounts in which such additives are normally emr~loyed in
- 12 -
1100381 c 789(R)
liquid fabric washing detergent compositions. Examples of
these additives include lather depressants, anti-
redeposition agents such as carboxymethylcellulose (CMC),
alkaline salts such as alkali metal carbonate or alkali
metal hydroxides, and, usually present in very minor
amounts, fluorescent agents, perfumes, enzymes such as
proteases and amylases, germicides and colourants. When
CMC is used it has been found advantageous to incorporate
also a stabilising agent for this material, e.g. a hydro-
genated castor oil (castor wax), carnauba wax, b~eswax,etc.
The balance of the compositions is water, which is
usually present to the extent of about 40% to about 75% by
weight, preferably about 45% to about 65% by weight.
To ensure effective detergency the liquid detergent
compositions should be alkaline, and it is preferred that
they should provide a pH within the range of about 9 to 12,
preferably about pH 9.5 to about 11 when used in a~ueous
solution of the composition at the recommended concen-
tration. To meet this requirement, the undiluted liquid
composition should also be of high pH, for example about
pH 12 to 13, preferably about pH 12.5. It should be noted
that an excessively high pH, e.g. over about pH 13 is less
desirable for domestic safety. The ingredients in any such
highly alkaline detergent composition should of colrse be
chosen for alkaline stability, especially for pH-sensitive
materials such as enzymes, and a particularly suitable
proteolytic enzyme in this respect is available unler the
- 13 -
llQ~3~ C 789 (R)
trade name "Esperase". ~
It is desirable to include in the compositions an
alkaline buffer, for example alkali metal carbonate, to
maintain the pH of at least 9 during use, particularly under
conditions of use, for example in hard water or at low
product concentrations, when the alkali metal orthophosphate
is precipitated in the form of its calcium salt and cannot
itself then act as an alkaline buffer. Alkali metal
silicates, for example sodium ortho-, meta- or preferably
neutral or alkaline silicates, which are commonly used as
alkaline buffers are more difficult to incorporate in the
homogeneous liquid compositions, especially at higher sodium
tripolyphosphate levels. An alkali metal hydroxide,
preferably potassium hydroxide, may alternatively or
additionally be used to provide an initially high pH.
The liquid detergent compositions can be made easily
by adding the ingredients to water in conventional detergent
processing equipment. It is preferred for higher levels of
phosphate builders to heat the water first, e.g. to about
60C to 80C, and then to add the inorganic detergency
builders, followed by the detergent active compoun~ or
compounds and then other organic materials. Alternatively,
if desired, the heat of reaction between acidic and alkaline
ingredients may be used to raise the temperature and
facilitate mixing of the ingredients.
The resultant compositions have viscosities in the
range from about 20 to 2,000, especially about 50 to
about 1,000 centipoise, as measured at room temperature in
~ 1~
~1003~ (~ 789 (R)
a Brookfield viscometer (Spindle No.3, 30 rpm).
The invention is illustrated by the following
Examples in which parts and percentages are by weight except
where otherwise indicated.
Examples I to X
A series of stable homogeneous liquid detergen~
compositions were made to the following formulations:
3~
~;
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oo o
1~ ~1 ' rl
1~ rl rl
r~,U)
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C~ ~ rl)~
X U~ ir~ 1 rl O
C~
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o ~ a,
o~ Lr~
. . ~ O 1'
X ~ I O ~ ~ ~ I u~ c~
~1 ~_, ~, L~ r-l 5~
~ a~ r
~ o r-l J~ ~:
~) O
x ~ I ~ ~ ~ I r~
u~ ~ ~ ~ ^ a~ r
a~ Lr~u~ a~
~D
c~
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a~ ~ ~ ~ ~ ~ Q
c~ c~
h _- a
a~ L~ ~ ~ a
o u~
X ~ C rl
L~ ~ O C r-l
~ S C~ ~
~ r-lE~ ~ I
a~
X ~ ~ O O L~ J~ ~ U~r~ a~ ~D
u~ ~ u~
~ a~u~
S a~ ~ r~
C~ N O O
X ~ ~ O O t~J ~ (~1 CO r-l S O
~ ~ ~ u~ ~ a) ~
tq P ~ rO
a~-- C ~
x ~ ~ o o I~ ~ Lr~ ~I ~ a) ~ ~,
NV O a~
s~ I
a,
P
~ O r~
X ~ J O O I(-\.1 (~J Lr~ I ~ r~ `~
,~ r-l a~
r-l
O
~:1 r-l
a) a) a) ~t;~ a
O ~ ~ ,5: 0 t
~ S ~ ,r ~ a)
a) I S ~ ~ o co ~ ^
Q, Uq ~ a,~ rl S ~
a) a) tq o ~ ~ C~ o~ o ~ uq O
N '~ O S rlrl ~ r~
rl S 0~ C~ X
a) ~ o ~ o c~ u~ p ~1
P ~ ~ S ~ rl
r~ ~ a) a) tq ~ uq
r~l ~ ~ O ~ r-l ~ a) a~ a)
~ ) 0~ 0 ~) S O a) r 1 uq
J~ .~ J~ ~ rl ~ r~ Uq ~
rl ~J ~3 h ~: ~ a r- a
a~~ ~ t~ i a~ X ~3r~ ~ ~
rl O rl J_> rl tq H X 0~ r
tq ~ Uq r~ E~ O L~ ~ J~ (r
a~~ o~ o ~ uq ~ uq S,
h rl r~ r-l rl ~ O ~ al ri ~d a~ ~ X a P
r-l ~ J~ C~ ~ ~ ~ 5 ~ H L~l Z O
~r,O U~ t~ O O O O rl O ~
H ~ L~ 3
~1003~1 c 789 (R)
All these formulations had good detergency properties
due to the relatively high detergency building properties of
the sodium tripolyphosphate and potassium orthophosphate. -;-
Example XI :
A clear, homogeneous low-sudsing liquid detergent
composition was made to the following formulation:
Ingredient %
Sodium alkyl (C1 -C12) 6.0
benzene sulphonate
Tallow fatty amide - 11 EO 2.0
Dimerised oleic acid 5.0
Sodium tripolyphosphate 10.0
Potassium orthophosphate 6.0
Sodium xylene sulphonate 5.0
Potassium hydroxide 1.0
Potassium carbonate 5.0
Water 60.0
This liquid composition was readily pourable and was
stable on storage down to about -10C. Replacement of the
potassium carbonate by sodium carbonate also gave a clear
stable liquid but of higher viscosity. In both cases the
alkaline buffering effect of the carbonate improved the
detergent properties of the composition.
Example XII
A homogeneous clear built liquid composition was
prepared to the following formulation:
- 17 -
.
~ 38~ C 789 (R)
Ingredient %
Potassium alkyl benzene sulphonate 7.50
Alkyl (C16 C18) 5 1.45
Alkyl (C -C 5) - 11 E0 o.80
Dimerised oleic acid 5.50
Sodium tripolyphosphate 13.00
Potassium orthophosphate 7.70
Sodium xylene sulphonate 6.10
Fluorescent agent 0.15
Water 57.80
1 Made by reaction between orthophosphoric acid and
pot,assium hydroxide during production of the
composition.
This composition had a low viscosity and was found to
be stable down to -4C.
~xample XIII
A clear isotropic high-sudsing built liquid detergent
composition was prepared to the following formulation:
In~,redient %
Potassium alkyl benzene sulphonate1 8.0
Alkanol (Cg-Cll) - 8 E0 2.0
Potassium hydroxide 4.5
Sodium tripolyphosphate 16.5
Potassium orthophosphate 5.0
Coconut fatty diethanolamide 2.0
Potassium coconut soap 1.0
~odium xylene sulphonate/toluene 6 0
sulphonate (4~
Water 55.9
- 18 -
C 789 (R)
lla~3sl -
Calculated in acid form
2 Formed from dipotassium hydrogen orthophosphate by
reaction with the potassium hydroxide
This product was found to have good stability (-5C to
52C) and a low viscosity of about 100 to 200 centipoise at
room temperature (Brookfield Spindle No.3, 30 rpm) at pH
12.5. Replacement of the nonionic detergent compound with r
other similar materials, e.g. alkanol (Cg-Cll) - 6 EO,
alkanol (C12-C15) - 7 EO or alkanol (C12-C15) - 3 F.O was
found to be equally satisfactory.
Example XIV
A homogeneous clear built liquid composition was
prepared to the following formulation:
Ingredient %
Potassium alkylbenzene sulphonate 6
(C11-C12) (as acid)
C -C linear primary alcohol,
co~de~ed with 7 moles of ethylene/
propylene oxide (mole ratio 88:12) ?.5
Oleic acid 5.0
Sodium tripolyphosphate 16.5
Potassium orthophosphate 6.o
KOH 4.0
Sodium toluene sulphonate 6.o
CMC (s~dium salt) 0.25
Castor wax 0.25
Fluorescer, dyes, perfume etc. 0.3
Water 53.2
- 19 -
11003~1 C 789 (R)
The viscosity was 300 cp, the pH 12.5, and the product
was stable over prolonged standing periods at -5 and + 37C.
- 20 -
