Note: Descriptions are shown in the official language in which they were submitted.
~10(~3~3Z
C 792 t~)
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 formu-
lation is very difficult, since they should be physically
stable under a wide rangé of storage conditions, for
example from about -4C to +37C. Also they should have
satisfactory pouring properties despite containing
relatively high concentrations of detergent ingredients,
especially builder salts so that ideally they have per-
formances equivalent to the usual powdered detergent com-
positions.
The prior 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
acceptable compositions as far as their physical charac-
teristics are concerned, their detergency and other l~ash-
ing properties tend to be unsatisfactory. For exampl~, with
the alkali metal.pyrophosphates there are often depo.,its
formed on the clothes, especially when the products ~Ire
used at exceptionally low product concentrations or -t
-- 2
1~003~2
C 792 (R)
high temperatures. 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 compo-
sitions sufficiently high levels of the conventional deter-
gency builders such as sodium tripolyphosphate without
causing severe problems of separation or solidification
of the liquid compositions.
According to the present invention we have found
that satisfactory, relatively high,'leve]s of certain
mixtures of sodium tripolyphosphate and sodium or potassium
orthophosphate may be incorporated into aqueous hetero-
geneous stable liquid compositions, that is compositions
with a suspended solid phase, which have good physical
properties, with the aid of particular stabilising agents
as described hereinafter. Instead of the sodium tripoly-
phosphate the potassium salt may be used, but this is more
expensive and for convenience the use of the sodium salt
is described and illustrated in the specification.
Insofar as these two detergency builder materials
function normally in different ways i.e. by sodium tripoly-
phosphate acting as a sequestrant detergency builder and the
alkali metal orthophosphate functioning as a precipitant builder,
it is somewhat surprising that a mixture of ~he materials func-
tions so effectively. In particular, when sodium orthophosphate
38~
C 792 (R)
is used alone as a detergency builder it tends to cause
inorganic deposition on the washed fabrics, which is
accompanied by soil redeposition, but in the presence of
the sodium tripolyphosphate the soil redeposition is sig-
nificantly decreased whilst the detergency is apparently
boosted. Moreover, in comparison with the use of sodium tri-
polyphosphate alone as detergency builder, the same amount
of the mixed sodium tripolyphosphate and alkali metal ortho-
phosphate detergency builders shows improved detergency and
soil redeposition properties, especi~ally 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 con-
densed phosphates such as sodium tripolyphosphate tend tb
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 tripoly-
phosphate 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 fabric washing liquid
detergent compositions containing a suspended solid phase
according to the present invention. The formation of the
heterogeneous detergent compositons with r,luch higher
11~038Z
C 792 (R)
detergency builder levels than has hitherto been possible
is particularly advantageous. They can be made with good
physical properties without very expensive multiple stabil-
ising agent systems or complicated processing conditions.
The ratio of the sodium tripolyphosphate to the alkali
metal orthophosphate in the detergent composition is from
about 10:1 to about 1:10, particularly about 5:i 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
orthophosphate 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 5% to about 35% by weight
of the composition, preferably from about 10% to about
30%, 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 2%, preferably at least about 4%
by weight of the composition.
~hen higher levels of sodium tripolyphosphate a-~e used,
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C 792 (R)
i.e. above about 12% by weight of the composltion, it is
particularly advantageous to use a type of sodium tripoly-
phosphate which hydrates rapidly, as this aids its solubility,
particularly for use in compositions containing higher levels
of sodium tripolyphosphate. Suitable materials are commer-
cially available with a high, i.e. greater than 50~, phase I
content, and they may also be partially or fully prehydrated.
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 "Surface Active Agents and
Detergents", Volumes I and II, by Schwartz, Ferry and 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 s~lphonales 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 second-
ary alkyl sulphates, especially those obtained by sulphatingthe
higher (C8-C18) alcohols produced by reducing the glycerides of
tallow orcoconut oil;sodium and potassium alkyl (Cg-C20) benzene
sulphonates, particularly sodium linear secondary alky L' (C~o-C15)
benzene sulphonates; sodium alkyl glyceryl ether sulphates, es-
pecially those ethers of the higher alcohols derived frcm tall(~Jor coconut
-- 6
110~3~32
C 792 (R)
oil and synthetic alcQhols derived from petroleum;sodium coconut
oil fatty acid monoglyceride sulphates and sulphonates; sodium
and potassium salts of sulphuric acid esters ofhigher (Cg-Cl8)
fatty alcohol-alkylene oxide, particularly ethylene oxide, reac-
tion products; the reaction products of fatty acids such as
coconut fatty acids esterified with isethionic acid and neutral-
ised with sodium hydroxide; sodium and potassium salts of fatty
acids amides of methyl taurine; primary or secondary alkane mono-
sulphonates such as those derived by reacting alpha-olefins
(C8-C20) with sodium bisulphite and those derived by reacting
paraffins with S02 and C12 and then hydrolysing with a base to
produce a random sulphonate; and olèfin sulphonates, which term
is used to describe the material made by reacting olefins, par-
ticularly alpha-olefins, with S03 and then neutralising and
hydrolysing the reaction product.
Although in general the sodium salts of the anionic
detergent compounds are preferred for cheapness, the potas-
sium salts can sometimes be used to advantage, particularly
in compositions with high levels of other sodium salts such
as sodium tripolyphosphate and sodium orthophosphate.
Of the anionic detergent compounds, alkali metal alkyl
C10-Cl5) benzene sulphates are particularly preferred, both for ready avail-
ability a~d cheapness and also for their advantageous solubilityproperties.
If desired, nonionic detergent active compounds may be
used as the sole detergent compounds, or preferably in admix-
ture 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 E0; i.e. 5 to 25 units of
ethylene oxide per molecule; the condensation products
110C~3~32
C 792 (R)
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.
Another example of suitable nonionics are nonionics obtained
by first ethoxylating and subsequently propoxylating an or-
ganic hydroxyl-group containing radical, e.g. an aliphatic
primary or secondary C8-C18 alcohol. Other so-called non-
ionic detergent active compounds include long chain tertiary
amine oxides, long chain tertiary phosphine oxides and di-
alkyl sulphoxides. I
Mixtures of detergent active compounds, for example
mixed anionic or mixed anionic and nonionic compounds may
be used in the detergent compositions, particularly to im-
part thereto controlled low sudsing properties. This is
particularly beneficial for compositions intended for use
in suds-intolerant automatic washing machines. Mixtures
of amine oxides and ethoxylated anionic compounds can also
be beneficial.
Amounts of amphoteric or zwitterionic detergent
active compounds can also be used in the liquid detergent
compositions of the invention but this is not normally
desired due to their relatively high cost. If any am-
photeric 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 non-
ionic detergent active compounds. Soaps, i.e. alkali metal
salts such as sodium or potassium salts of C10-C22 fatty
acids such as coconut fatty acids and oleic acid, including
110(~38Z
- C 732 (R)
polyme~ic fatty acids such as dimerized oleic acid, may also
be used in the compositions of the invention, particularly
in ternary mixtures with synthetic anionic and nonionic
detergent active compounds, which have low sudsing properties.`
The amount of the detergent active compound or compounds
used is generally in the range of from about 2.0% 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 ~:5, preferably about 1:1 to about 1:3
parts by weight.
The alkali metal orthophosphate used may be sodium or
potassium orthophosphate. The former is cheaper and more
readily available but the latter may be advantageous:!y
used, particularly at high total phosphate levels in the
products. The potassium orthophosphate can be added as
such, or orthophosphoric acid may be neutralised by a
potassium salt such as potassium hydroxide during production
of the compositions. It should be noted that the term alkali
metal orthophosphate includes the mono-, di- and tri-ortho-
phosphates.
In the liquid detergent compositions of the invlntion
it is essential to have present a stabilising agent,
3~32
C 792 (R)
particularly in compositions containing higher phosphate levels,
to maintain stable suspensions of the solid phase an~/or to
avoid separation of different liquid phases, particularly
when nonionic detergent compounds are present. Suitable
stabilising agents for these compositions are polymeric stabil-
ising agents which are copolymers of maleic anhydride with
either ethylene, styrene or preferably vinyl methyl ether.
Such materials are commercially available, for example under
the trade name "Gantrez", for 1:1 copolymers of maleic an-
~ hydride with vinyl methyl ether, whi'ch havè a specific vis-
cosity of about 0.1 to 4.5, preferably 0.1 to 0.6 (measured
in solution (1 g in 100 ml) of methyl ether ketone at 25 C).
Other copolymers of maleic anhydride with ethylene are avail-
able under the trade name "EMA". The copolymers are hydro-
lysed and neutralised in the compositions and they may also
be partially esterified with any nonionic compound used. It
should be noted that the presence of hydrotropes may be
undesirable in the compositions, particularly at higher
levels where they may detract from the stability of the
products.
The amount of such copolymeric stabilising agents is
preferably about 0.1% to about 2%, especially about 0.3%
to about 1.5~o~ by weight of the composition.
It is desirable to include one or more anti-depo-
sition 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 prefer~ed
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110~3~3Z
C ~S2 (R)
anti-de~position agents are homo- and copolyacrylates, e.g.
sodium polyacrylate, the sodium salt of copolymethacrylamide/
acrylic acid and sodium poly-alpha-hydroxyacrylate, 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. Other anti-
deposition agents include phosphate esters of ethoxylated
aliphatic alcohols, polyethylene glycol phosphate esters,
and certain phosphonates such as sodium ethane-1-hydroxy-
1,1-diphosphonate, ethylenediamine tetramethylene phosphonic
acid 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 about 5.0%, preferably about 0.2% to about 2% by
weight of the compositions.
It is also possible to include in the detergent com-
positions 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 achie-~e
particularly low phosphorus contents in the detergen~; com-
positions for environmental reasons. Examples of suc~
other detergency builders are amine carboxylates, su h as
sodium nitrilotriacetate. However, it is desirable t have
-- ~.1 --
11003~ c 792 (R)
no other phosphate detergency builders present othe~ 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 tripoly-
phosphate, 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 pyrophosphate present in the
compositions.
The liquid detergent compositions of the invention can
contain any of the conventional additives in the amounts in
which such additives are normally employed in liquid fabric
washing detergent compositions Examples of these additives
include lather boosters such as alkanolamides, particularly
the monoethanolamides derived from palm kernel fatty acids
and coconut fatty acids, lather depressants such as alkyl
phosphates, silicones and long chain soaps, anti-redeposi-
tion agents such as sodium carboxymethylcellulose, alkaline
salts such as sodium silicate, alkali metal carbonate or
alkali metal hydroxides, fabric softening agents , and,
usually present in very minor amounts, fluorescent agents,
perfumes, enzymes such as proteases and amylases, ger-
micides and colourants.
The ~alance of the compositions is water, which is
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`` 110~38Z
C 792 (R)
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 aqueous
solution of the composition at the recommended concentràtion.
To meet this requirement, the undiluted liquid composition
should also be of high pH, for example about pH 11 to about
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 composi-
tion should of course be chosen for alkaline stability, es-
pecially for pH-sensitive materials such as enzymes, and a
particularly suitable proteolytic enzyme in this respect
is available under the trade name "Esperase".
It is desirable to include in the compos1tion an alka-
line buffer, for example alkali metal carbonate, to main-
tain 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 orthophos-
phate is precipitated in the form of its calcium salt and
cannot itself then act as the alkaline buffer. Aiternatively,
alkali metal silicates, for example sodium ortho-~:meta- or
preferably neutral or alkaline silicates may be used. The
presence of such alkali metal silicates at low levels of,
for example about 1% to about 5% by weight, is also ad-
vantageous in decreasing the corrosion of metal part, in
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110~382
C 792 (R)
washing machines. An alkali metal hydroxide may alternatively
or additionally be used to provide an i~itially high pH.
The liquid detergent compositions can be made relatively
easily. It is preferable, particularly for products with
lower sodium tripolyphosphate levels, to split the water
required into two parts and one part is heated and then mixed
with the inorganic builder salts and the other is mixed with
the other organic ingredients. The two parts are then blended
together to give a suspended liquid system. Alternatively,
compositions of higher sodium tripol'yphosphate content in
particular may be made by firstly dissolving a preformed
copolymeric stabilising agent in water and partly ester-
ifying the copolymer with some nonionic detergent active
compound, adding the anionic detergent active compounds, any
soap and any further nonionic compound to the resultant
mixture, and then adding the phosphate salts and any sodium
silicate. The heat of reaction between acidic and alkaline
ingredients may be used to raise the temperature and facili-
tate mixing of the ingredients.
The resultant compositions have viscosities in the range
from about 50 to 2,000 centipoise, especially about 100 to
about 1500 centipoise, as measured at room temperature in 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 1 ar.d 2
Two stable heterogeneous liquid compositions we~e made
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110038Z
C 792 (R)
to the-following formulations:
Ingredient Percentages
Ex 1 Ex 2
Sodium alkyl (C11-C15) benzene
sulphonate 6 6
Tallow alcohol - 18 EO 2 2
Alkyl phosphate 1
Dimerised oleic acid 2 - 2
Coconut ethanolamide
Sodium tripolyphosphate 10 10
Sodium orthophosphate 8 8
Stabilising agent 3
Water 72 71
Obtained as Hostaphat
Obtained as Empol, neutralised to the sodium salt
in processing
3 Copolymer of maleic anhydride with vinyl methyl
ether 1:1, obtained as Gantrez AN 119, hydrolysed
and neutralised in processing
The compositions of Examples 1 and 2 had low sudsing
properties due to the alkyl phosphate or the dimerised fatty
acid, and were suitable for use in front loading automatic
washing machines. In these examples, the combined amount
of sodium tripolyphosphate and sodium orthophosphate were
equivalent in~hard water detergency building properties
to a level of about 35% of sodium tripolyphospha~e alone,
which of course is more than could be included into .
stable aqueous liquid detergen~ composition.
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110~3~ C 792 (R)
Examples 3 to 5
T~ree stable, heterogeneous built liquid detergent
compositions were prepared to the following formulations:
Ingredient PercentageX
Ex 3 Ex 4 Ex 5
( 13 15 2.5 2.5 2.5
Potassium alkylbenzene 1
sulphonate 6.5 6.5 6.5
Sodium tripolyphosphate 11.0 16.0 18.0
Potassium tripolyphosphate - - 3.0
Potassium orthophosphate 7.0 5.0 ~.0
Copolymer of maleic anhydride
and vinyl methyl ether (1:1) 0.5 0.5 0.5
Dimerised oleic acid (K salt) 1 5.0 5 5.0
Sodium carboxymethylcellulose o.6 o.6 0.6
Sodium alkaline silicate 5.0 5.0 5.0
Fluorescent agents 0.3 0.3 0.3
Blue dye 0.02 0.02 0.02
Perfume o.3 0.3 0.3
Water to 100.0 tolOO.O tolOO.O
Calculated in acid form
These compositions were prepared by firstly reacting
the maleic anhydride copolymer with an equal amount of the
nonionic detergent compound in water at 80C. Then more
water was added with potassium hydroxide, followed by the
alkyl benzene sulphonate and dimerised oleic acid which
were neutralised by the potassium hydroxide. The remaining
nonionic detergent compound and minor ingredients were
then added, ~ollowed by the two phosphate salts and lastly
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110~3~z
C 792 (R)
the silicate. The products of these Examples had ac~eptable
viscosities of 450 cp, 700 and 950 cp at room temperature
(Brookfield Spindle No. 3, 30 rpm), and they were all about
pH 12.5 (undiluted). The detergencies of the compositions
were determined in a Terg-O-Tometer at 50C and it was found
that the compositions of Examples 4 and 5 were particularly
good, being superior to a comparative product which contained
21% sodium tripolyphosphate, i.e. about the maximum level
of that material which could be used in a stable aqueous
liquid composition as the sole dete~gency builder.
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