Note: Descriptions are shown in the official language in which they were submitted.
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cC.~76
The invention relates to powdered detergent compositions
which are adapted for fabric washing, and in particular to such
compositions containing synthetic detergent active compounds
together with phosphate detergency builders.
- 5 The most commonly used detergency builders are the
condensed phosphates, especially sodium tripolyphosphate, but
it has been suggested that the use of phosphate detergency
builders can contribute to eutrophication problems. There have
been very many suggestions for alternative, mainly organic,
materials to be used as detergency builders instead of the
condensed phosphates, but most of these materials tend to be
unsatisfactory for one reason or another, for example they are
; less efficient or biologically unacceptable, or they may simply
be too expensive.
It has also been proposed to mitigate the problems of - -
eutrophication by using decreased levels of condensed phosphate
detergency builders, with or without the presence of other
detergency builders, but few of these proposals have approached
commercial acceptance. ~hus, when reduced levels of sodium
tripolyphosphate are used without supplemental builders, there
can be considerable problems when using the compositions in
hard water if there is insufficient phosphate to sequester all
the calcium ions present, as this causes the precipitation of
insoluble calcium phosphate salts which can be deposited on -the
washed fabrics, besides giving decreased detergency due to
inadequate softening of the water sometimes accompanied by
precipitation of insoluble calcium salts of anionic detergent
compounds.
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On the other hand, when a condensed phosphate builder is
used with so~e non-phosphate detergency builders,
the former may prevent the latter from functioning
effectively, especially in the case of other detergency builders
which act by precipitating the calcium salt, for example sodium
carbonate. Moreover, there are relatively few other detergency
builders which are completely environmentally acceptable and
which are good enough to be worth using even in part replacement
for a condensed phosphate builder.
In recent years a lot of effort and expense has been
directed to solving these problems, with the synthesis and
evaluation of great numbers of new materials. However, it
would inevitably take several years for any completely new
material to be cleared for domestic use, and therefore most
recent interest has centered on known non-phosphate materials
which act as builders by either sequestration, precipitation
or ion-exchange and which are known to be environmentally safe.
The present invention resides in the surprising discovery
that specific mixtures of the well known phosphate detergency
builders can themselves be chosen to give good fabric washing
detergencies at relatively low phosphorus levels. As mixtures
of such phosphates are in general well known in detergent
products, especially in products other than for fabric washing,
it is surprising that this benefit has not been previously
noticed and it`s importance understood. In a preferred aspect
the invention enables satisfactory detergent products to be
formulated at relatively low phosphate levels without the use
of supplementary non-phosphate builders.
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According to the present invention, a powdered alkaline
fabric washing detergent composition comprises from about 50,b
to about 30% of a synthetic anionic, nonionic, amphoteric or
zwitterionic detergent compound or a mixture thereof, and from
about 10% to about 30% of mixed sodium tripolyphosphate and
alkali metal orthophosphate in the ratio of from 10:1 to 1:5
parts by weight, wherein the amount of sodium tripolyphosphate
is at least about 5%~ and the amount of any alkali metal
pyrophosphate is not more than about 5%~ all these percentages
being by weight of the total detergent composition, and the p~
- of a 0.1% aqueous solution of the composition is from 9 to 11.
The invention includes a process for making these detergent
compositions. By the suitable choice of the amounts of the sodium
tripolyphosphate and alkali metal orthophosphate it is possible
to formulate effective detergent compositions containing lower
phosphorus levels than in comparable conventional sodium
tripolyphosphate-based detergent compositions with similar
detergency building capabilities. Insofar as the two essential
detergency builder materials function normally in different
2~ ways, ie by sodium tripolyphosphate acting as a sequestrant
detergency builder and by alkali metal orthophosphates
functioning as precipitant builders, it is somewhat surprising
that a mixture of the materials functions so effectively. In
particular, when alkali metal orthophosphates are used as
detergency builders, they normally tend to cause inorganic
deposition which promotes soil redeposition on the washed
fabrics, but in the presence of the sodium tripolyphosphate the
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soil redeposition is significantly decreased, but not by
inhibiting the calcium orthophosphate precipitation which would
detract from the detergency benefit. Moreover, in comparison
with the use of sodium tripolyphosphate alone as detergency
builder, the same amount of the mixed sodium tripolyphosphate
and alkali metal orthophosphate shows improved detergency
building capacity and low soil redeposition properties.
The alkali metal orthophosphate used is either potassium
or preferably sodium orthophosphate, as the latter is cheaper
and more readily available. Normally the tri-alkali metal
salts are used, but orthophosphoric acid or the di- or mono-
alkali metal salts, eg disodium hydrogen orthophosphate or
monosodium dihydrogen orthophosphate could be used if desired
to form the compositions. In the latter event other more
i5 alkaline salts would also be present to maintain a high pH in
the end product, with full neutralisation to the trialkali metal
orthophosphate salts. The use of a mixture of the monosodium
and disodium hydrogen orthophosphates in the ratio of about 1:3
to 2:3, especially about 1:2, is particularly advantageous, as
such a mixture is made as a feedstock for the production of
sodium tripolyphosphate and is therefore readily available.
Both the alkali metal orthophosphate and the sodium tripolyphos--
phate can be used initially as the anhydrous or hydrated salts, ---
for example as trisodium orthophosphate dodecahydrate and penta-
sodium tripolyphosphate hexahydrate, but hydration normally takes
~ place during detergent powder production. The amounts of the
; salts are, however, calculated in anhydrous form. Potassium
tripolyphosphate could be used instead of sodium tripolyphosphate,
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if desired, but this would be much more expensive and of no
commercial benefit.
~ here have in the past been many suggestions for using
mixed phosphate detergency builders, for example mixtures of
sodium pyrophosphate and sodium tripolyphosphate, so as to give
improved detergency building properties, or other benefits
rather than to decrease the phosphorus content. ~oreover, it
is well known that the condensed phosphates such as sodium
tripolyphosphate tend to degrade to form other phosphates under
aqueous alkaline conditions at high temperatures, which are
commonly met during detergent processing. Sodium tripolyphos-
phate degrades to give a mixture of mainly sodium pyrophosphate
with a small amount of sodium orthophosphate, so that spray
dried detergent products contain amounts of all three of these
materials.
- However, to the Applicants' knowledge, it has not been ~--
proposed hitherto to use the specific mixtures of sodium tripoly-
phosphate and alkali metal orthophosphate in the proportions set
out in the powdered alkaline fabric washing detergent compositions
according to the present invention. When mixtures of these
materials have been proposed for use before, it has been at
unsuitable levels or in other types of compositions often
containing ingredients which are unsuitable for use in fabric
washing compositions. For example, the pE of powdered dish-
washing compositions is generally too high for fabric washingpurposes, and products which contact the skin, for example
detergent tablets, are generally about p~ 7-8 which is too low
for optimum detergency with the new mixed phosphate builder systems.
.
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~ hilst the ratio of the sodium tripolyphosphate to the
alkali metal orthophosphate can be varied from 10:1 to 1:5 parts
by weight, it is preferred to have a ratio of from 8:1 to 1:2,
especially with an excess of the sodium tripolyphosphate over
the alkali metal orthophosphate, within the ratio of from 5:1 to
l:i parts by weight, for example from about 4:1 to about 3:2,
and more especially from about 3:1 to about 2:1 parts by weight,
respectively. These ratios of sodium tripolyphosphate to
alkali metal orthophosphate are especially suitable for
detergent compositions used at relatively high product
concentrations, ie about 0.3/0 to about 0.8% by weight, as is
common practice in Europe, especially in front-loading automatic
washing machines, and where relatively high levels of phosphates
are allowed in the products, ie equivalent to about 4,/o to -
about 7% P.
However, for detergent compositions which are to be used -
at relatively low product concentrations, ie from about 0.1%
to about 0.3~o, as is common practice under North American
washing conditions, especially in top-loading automatic washing
machines, and where relatively low phosphate levels are
permitted in the products, ie equivalent to less than about
4h P, it may be desirable to increase the proportion of the
alkali metal orthophosphate in the products. The ratio of
sodium tripolyphosphate to alkali metal orthophosphate can then
be from 2:1 to 1:5 parts by weight, preferably from 1:1 to 1:5,
for example from about 1:1 to 1:2 or 1:3 parts by weight,
respectively. Alternatively, when especially low phosphate
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10~73 cC.776
levels are enforced it may be beneficial to have a supplementary
non-phosphate builder, whilst still achieving optimum detergency
building from the phosphate builders in the compositions
according to the invention.
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 in the detergent compositions or according to
the maximum permitted phosphorus content. Within the
requirements of a total sodium tripolyphosphate and alkali
metal orthophosphate level of about 10~/o to about 30~o by weight
of the product, it is preferable to have a sodium tripolyphos-
phate content of from about 10% to about 20%~ and an alkali
metal orthophosphate content of from about 3h to about 15%~
especially about 5% to about 10%~ by weight of the product.
The total amount of sodium tripolyphosphate and alkali metal
orthophosphate is preferably at least about 15%~ up to about
25% by weight of the composition.
It may be observed that as the mixed sodium tripolyphos-
phate and alkali metal orthophosphate detergency builders are
equivalent in detergency b`uilding properties, ie calcium
binding capacity, to larger amounts of sodium tripolyphosphate
used alone, this gives the choice of making detergent
compositions of either increased detergency building properties
25 by using the same total phosphate level, or with similar
detergency building properties at a lower total phosphate level.
The latter choice leaves some extra "room" in the compositions
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cC.776
which can either by taken up by cheaper fillers or by other
beneficial ingredients, for example extra amounts of b]eaching
agents such as sodium perborate or percarbonate, fabric
softening agents, or amounts of other detergency boosting
materials.
This new freedom to detergent manufacturers is of
considerable commercial benefit. Thus, when some cheap filler,
for example sodium sulphate, is used with a lower total phosphate
level than used previously with sodium tripolyphosphate as the
sole builder, the result is a substantial cost saving which can
be passed on to the consumer. The same lower phosphate level
can also be used to meet governmental or other restrictions as
described previously, and if a cheap filler is not then used
the overall performance of the compositions may if desired be
boosted by some extra beneficial ingredients. Alternatively,
the same total phosphate level may be retained as the original
tripolyphosphate level alone, but in this case the overall -
detergency building capacity is boosted. The cost saving
aspect of the compositions of the invention is of particular
commercial benefit, especially when it can be achieved whilst
still meeting lower phosphate restrictions, and it is remarkable
that this has not been appreciated hitherto.
It is preferable that the only phosphate detergency
builders used to make the compositions of the invention should
be the sodium tripolyphosphate and alkali metal orthophosphate.
In particular, it is desirable to add no alkali metal, ie
sodium or potassium, pyrophosphates to the compositions as they
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cC.776
tend to increase inorganic deposition. ~oreover, the presence
of significant levels of the alkali metal pyrophosphates instead
of the sodium tripolyphosphate or alkali metal orthophosphate
leads to lower detergency building capacities within the limited
phosphate levels permitted. However, as mentioned earlier, some
sodium pyrophosphate is produced with a lesser amount of sodium
orthophosphate by hydrolysis of sodium tripolyphosphate under the
hot alkaline conditions met during spray drying, so low levels,
ie up to about 50,h, of sodium pyrophosphate are unavoidable in
- 10 spray dried powders. Preferably the total amount of phosphate
materials present in the detergent composi~ions is not
more than about 30% by weight of the compositions. It should
be noted that theamounts of the hydratable phosphate salts in
the compositions are to be determined on an anhydrous basis.
The detergent compositions of the invention necessarily
include from about 5% to about 30%~ preferably about 10% to
about 25%~ by weight of a synthetic anionic, nonionic,
amphoteric or zwitterionic detergent compound or mixture
thereof. Many suitable detergent compounds are commercially
20 available and are fully described in the literature, for --
example in "Surface Active Agents and Detergents", Volumes I
and II, by Schwartz, Perry and Berch.
The preferred detergent compounds which can be used are
synthetic anionic and nonionic compounds. The former are
25 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
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suitable synthetic anionic detergent compounds are sodium and
potassium alkyl sulphates, especially those obtained by
sulphating higher (C8-C18) alcohols produced for example from
tallow or coconut oil; sodium and potassium alkyl (C9-C20)
benzene sulphonates, particularly sodium linear secondary alkyl
(CiO-C15) 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 acid mono-
glyceride sulphates and sulphonates; sodium and potassium salts
of sulphuric acid esters of higher (Cg-Cl8) 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
15 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 by reacting 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
C10-C20 alpha-olefins, with S03 and then neutralising and
hydrolysing the reaction product. The preferred anionic
detergent compounds are sodium (C11-C15) alkyl benzene
sulphonates and sodium (C16-C18) alkyl sulphates-
Examples of suitable nonionic detergent compounds which maybe used include in particular the reaction products of alkylene
o~ides, usually ethylene oxide, with alkyl (C6-C22) phenols,
'
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i(38~';'3 cc .776
generally S to 25 EO, ie 5 to 25 units o~ ethylene oxide per
molecule; the condensation products of aliphatic (C8-C18)
primary or secondary linear or branched alcohols with ethylene
oxide, generally 6 to 30 EO, 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.
Mixtures of detergent compounds, for example mixed anionic
or mixed anionic and nonionic compounds may be used in the
detergent compositions, particularly in the latter case to
provide controlled low sudsing properties. This is beneficial
for compositions intended for use in suds-intolerant automatic
washing machines. We have also found that the use of some
nonionic detergent compounds in the compositions tends to
decrease the tendency of insoluble phosphate salts to deposit
on the washed fabrics.
- Amounts of amphoteric or zwitterionic detergent compounds
can also be used in the compositions of the invention but this
is not normally desired due to their relatively high cost.
If any amphoteric or zwitterionic detergent compounds are used
it is generally in small amounts in compositions based on the
much more commonly used synthetic anionlc and/or nonionic
detergent compounds. For example, mixtures of amine oxides
and ethoxylated nonionic detergent compounds can be used.
Some soaps may also be used in the compositions of the
invention, but not as the sole detergent compounds. ~hey are
particularly useful at low levels in binary and ternary mixtures
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together with nonionic or mixed synthetic anionic and nonionic
detergent compounds, which have low sudsing properties. The
soaps which are used are the sodium, or less desirably potassium,
salts of C10-C2~ fatty acids- It is particularly preferred that
5 the soaps should be based mainly on the longer-chain fatty acids
within this range, that is with at least half of the soap having
a carbon chain length of 16 or over. This is most conveniently
accomplished by using soaps from natural sources such as tallow,
palm oil or rapeseed oil, which can be hardened if desired, with
lesser amounts of other shorter-chain soaps, prepared from nut
-- oils such as coconut oil or palm ~ernel oil. ~he amount of such
soaps can be varied between about 0. 5% and about 25% by weight,
with lower amounts of about 0.5% to about 5h being generally
sufficient for lather control. Amounts of soap between about
2% and about 20%~ especially between about 5~0 and about 15%~
are preferably used to give a beneficial effect on detergency.
Apart from the detergent compounds and detergency builders,
the detergent compositions of the invention can contain any of
the conventional additives in the amounts in which such materials
are normally employed in fabric washing detergent compositions.
Examples of these additives include lather boosters such as
alkanolamides, particularly the monoethanolamides derived from
palm kernel ~atty acids and coconut fatty acids, lather
depressants such as alkyl phosphates and silicones, anti-
. ~ 25 redeposition agents such as sodium carboxymethylcellulose and
polyvinyl pyrrolidone, oxygen-releasing bleaching agents such
as sodium perborate and sodium percarbonate, per-acid bleach
precursors, chlorine-releasing bleaching agents such as
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trichloroisocyanuric acid and alkali metal salts of dichloroiso-
eyanuric aeid, fabric softening agents, inorganic salts such as
sodium sulphate, sodium carbonate and magnesium silieate, and,
usually present in very minor amounts, fluorescent agents,
perfumes, enzymes such as proteases and amylases, germicides and
eolourants.
It is partieularly benefieial to inelude in the detergent
eompositions an amount of sodium perborate, preferably between
about 10% and 40%, for example about 15% to about 30%, by
weight. It has been found that the bleaching action of sodium
perborate is boosted under the higher alkaline conditions which
also give optimum detergency building action for the alkali
metal orthophosphate. Thus, it becomes possible to achieve
improved bleaching properties by using the same levels of sodium
perborate as normal; or decreased levels of sodium perborate
ean be used to give equal bleaching properties to those of
eonventional produets with higher levels of perborate but with
sodium tripolyphosphate as the sole detergeney builder. ~he
latter option can also be used to further decrease the raw
20 materials eosts of the eomposition if a eheap filler is used in
plaee of part of the sodium perborate.
It is desirable to include one or more antideposition
agents in the detergent compPsitions of the invention, to
- deerease any tendency to form inorganic deposits on washed
25 fabries. The amount of any such antideposition agent
is normally from about 0.~% to about 5% by weight, preferably
from about 0.2% to about 2% by weight of the composition. The
preferred antideposition agents are homo- and co-polymers of
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acrylic acid or substituted acrylic acids, such as sodium
polyacrylate, the sodium salt of copolymethacrylamide/acrylic
acid and sodium poly-alpha-hydroxyacrylate, salts of copolymers
af maleic anhydrlde with ethylene, vinylmethylether or styrene,
especially l:i copolymers, and optionally with partial ester-
ification of the carboxyl groups especially in the case of the
styrene-maleic anhydride copolymers. Such copolymers
preferably have relatively low molecular weights, eg in the
range of about 5,000 to 50,000. Other antideposition agents
include the sodium salts of polymaleic acid and polyitaconic
acid, phosphate esters of ethoxylated aliphatic alcohols,
polyethylene glycol phosphate esters, and certain phosphonates
-- such as sodium ethane-1-hydroxy-1,1-diphosphonate, sodium
ethylene diamine tetramethylene phosphonate, and sodium 2-
phosphonobutane tricarboxylate. Mixtures of organic phosphonic
aclds or substituted acrylic acids or their salts with
protective colloids such as gelatin as described in our
Netherlands application 7602082 may also be used. The most
preferred antideposition agent is sodium polyacrylate having a
20 MW of about 10,000 to 50,000, for example about 27,000.
~ It ls also possible to include ln the detergent
compositions of the lnventlon minor amounts, preferably not
more than about 20% by weight, of other non-phosphate detergency
bullders, whlch may be elther so-called preclpitant builders or
sequestrant builders. ~his is of particular benefit where
~t is desired to increase detergency whilst using particularly
low levels of the essential sodlum tripolyphosphate and alkali
metal orthophosphate builders, so as to achieve low phosphorus
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contents in the detergent compositions. Examples of such other
detergency builders are amine carboxylates such as sodium
nitrilotriacetate, sodium aluminosilicate ion-exchange materials,
sodium citrate and soap, which can function as a detergency
builder as discussed above. However, such other builder
materials are not essential and it is a particular benefit of
the compositions of the invention that satisfactory detergency
building properties can be achieved with only phosphate builders
at lower levels than hitherto considered necessary.
It is also desirable to include in the compositions an
amount of an alkali metal silicate, particularly sodium ortho-,
meta- or preferably neutral of alkaline silicate. The presence
of such alkali metal silicates at levels of at least about 1%~
and preferably from about 5% to about i5% by weight of the
compositions, is advantageous in decreasing the corrosion of
metal parts in washing machines, besides giving processing
benefits and generally improved powder properties. The more
highly alkaline ortho- and meta-silicates would normally only
be used at lower amounts within this range, in admixture with
the neutral or alkaline silicates.
The compositions of the invention are required to be
alkaline, but not too strongly alkaline as this could result
in fabric damage and also be hazardous for domestic usage.
In practice the compositions should give a pH of from 9 to 11
in use in aqueous wash solution. It is preferred in particular
for domestic products to have a minimum pE of at least 9.25 -
and especially a pE of 9.5 or over, as lower pHs tend to be
less effective for optimum detergency building, and a maximum
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p~ of 10.5, as more highly alkaline products can be hazardous
if misused. We require the pH to be measured at the lowest
normal usage concentration of 0.1% w/v of the product in
water of 12~ (Ca), (French permanent hardness, calcium only)
at 50C so that a satisfactory degree of alkalinity can be
assured in use at all normal product concentrations. The p~
is controlled by the amount of alkali metal orthophosphate and
any other alkaline salts such as alkali metal silicate? sodium
perborate and sodium carbonate, the amount of the latter
preferably being not more than 20,~ by weight of the composition.
The presence of other alkaline salts, especially the alkali
metal silicates, is particularly beneficial because the
alkalinity of the alkali metal orthophosphates is diminished in
hard water due to precipitation of the calcium salt. The other
ingredients in the alkaline detergent compositions of the
invention should of course be chosen for alkaline stability,
-especially for p~-sensitive materials such as enzymes.
The detergent compositions of the invention should be in
free-flowing powdered form and can be produced by any of the
techniques commonly employed in the manufacture of such fabric
washing compositions, but preferably by slurry making and spray
drying processes. It is advantageous in the slurry making
step to be able to form the.alkali metal orthophosphate by
neutralisation of- orthophosphoric acid or by using so-called
"kiln-feed" which is a crude mixture of mono- and di-sodium
orthophosphates used in the preparation of sodium tripolyphos-
;phate. It has also been found that with the mixed sodium
-~ tripolyphosphate and alkali metal orthophosphate builders it
17
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is possible to use lower water levels than usual in the slurries
for spray drying purposes, which is of economic benefit. In
particular, slurry water conten-ts of about 50h tend to be
required for the conventional sodium tripolyphosphate powders,
whereas the slurry water content can be down to about ~0/0 or
even lower for making the mixed sodium tripolyphosphate and
sodium orthophosphate-based products of the invention.
The invention is illustrated by the following Examples in ~~~
which parts and percentages are by weight, and amounts of
ingredients are expressed on an anhydrous basis, except where
otherwise indicated.
Example 1
A spray dried powdered low sudsing detergent composition
was prepared to the following nominal formulation:
15 In~redient
Sodium (C -C15) alkyl benzene 7.0
sulphona~e
Tallow amide - 11 E0 condensate 1.5
Sodium hardened tallow soap 3.0
20 Sodium tripolyphosphate16.0
Sodium orthophosphate 6.0
Sodium alkaline silicate10.0
. Sodium sulphate 23.4
Sodium perborate 25.0
25 Sodium carboxymethylcellulose 1.5
Fluorescent agents and preservatives 0.5
Water 6.1
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~ his composltion was made by normal slurry making in a
turbo-mixer, using a slurry temperature of 80C and a final
slurry moisture content of 38% (which is significantly lower
than the usual moisture level of about 50% for sodium
5 trlpolyphosphate-based products), followed by counter-current
spray drying uslng an air inlet temperature of 300C and an
outlet temperature of 100C. The level of phosphate breakdown
by hydrolysis during processing under these condltlons was
- about 20%~ giving in the final product about 12.7% sodillm
10 tripolyphosphate, 6. 9% sodium orthophosphate and 204%
sodium pyrophosphate. ~he composition had good powder
properties and was stable during storage in laminated cartons
at temperatures up to 37C.
~his product, which had a phosphorus content of about 5%,
15 was compared for detergency against a commerclally available
heavy duty detergent composltlon (A) of similar nominal
formulation, except that it contained about 35% of sodium
tripolyphosphate (equivalent to about 9% phosphorus) instead
of the mixed sodium tripolyphosphate and alkali metal
orthophosphate ln the product of the invention, and consequently
lt had a decreased level of 9/0 sodium sulphate. The
detergency tests were undertaken using a product concentration
Of 0.6% in 40H water, using-a Lavamat Regina automatic washing
machine on the 95C cycle. Domestically soiled articles were
washed in 7 lb loads which included halved articles of varying
types lncludlng towels, tea-towels and pillowcases.
; The results showed a marginal preference for the
appearance of the articles washed using the composition of the
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07;~ Cc . 776
invention compared with the commercially available higher
phosphorus product. Similar results were achieved when the
tests were repeated using product concentrations of 0.4/0 and
0.8% in very hard water (40H), and when the product
5 concentration used was 0.6% in less hard water (25H), in
simulation of different practical washing conditions in
-- continental Europe. Further actual domestic washing tests
showed similar results for both products under these conditions
. . .
and also at low wash temperatures (30-40C) for washing mainly
synthetic fabrics. Replacement of the 7.00,h sodium alkyl
benzene sulphonate and 1.5% tallow amide - 11 EO condensate by
8.5% of sec-linear (C11-C15) alcohol - 9 EO condensate
(obtained as Tergitol 15-S-9) was found to improve the detergency
results for the composition of the invention.
Further tests were also carried out to determine the levels
of inorganic deposition on cotton terry towelling fabric at
produet coneentrations of 0.~/0 and 0.8% in 40H water (Ca:l~g,
~:1), under the same high temperature washing eonditions.
After 10 repeated wash eyeles the levels of the inorganie
deposits were as follows:
~0 deposits
Produet Coneentration Example 1 Product A
0.4% 1.3 2.0-
0.8% 2.6 0.2
These results show that the eomposition according to the
- invention is better at the lower produet eoneentration, but
gives more inorganie deposition at the higher produet
eoneentration under these harsh conditions. Other tests showed
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gellerally similar properties for the two products as regaIds
soil redeposition during washing and stain removal, but with
noticeably improved bleaching properties for the product of the
invention. It should be noted that the general similarity in
results between the product of the invention and comparative
composition (A) was achieved despite the much lower total
phosphate level in the former and a consequently decreased
materials cost.
Further tests were undertaken with a composition similar to
Example 1 to which 1% of ethane-1-hydroxy-1, 1-diphosphonate
and 1% of sodium polyacrylate (MW 27,000, sold under the trade
mark VERSICOL E7) were separately added as antideposition agents.
Both of these additives were found to lower the levels of
inorganic deposition on washed cotton terry towelling to 1.1%
and 1.2%, respectively under the same washing conditions
described above (at 0.8% product concentration in 40H water).
Decreased inorganic deposits were also found by using 0.5% of
1:1 copolymers of ethylene and maleic anhydride and of ethylene
and vinylmethylether, particularly when using higher levels of
nonionic detergent compounds in the products.
A further comparative test was undertaken with a product
having the same amounts of sodium tripolyphosphate and ortho-
phosphate as in Example 1 but with a decreased level of 6%
alkyl benzene sulphonate and 2% of nonionic detergent compound,
and with only 18% of the sodium perborate (with consequent
adjustment of the sodium sulphate level). ~his--product was
tested against a comparative conventional product having the
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same detergent compounds and 35~0 sodium tripolyphosphate and
- with 240,6 of sodium perborate.
The results of the comparative domestic washing machine
tests showed similar washing performance under the test
conditions using water of 35 and 15 German hardness, at 45C
and 95C. It was found in particular that the bleaching effect
of both powders was similar, despite the much lower perborate
,, _ . . .
content of the product according to the invention. In a
- further test, when the amount of the sodium perborate in a
comparative product was decreased to 18o/b~ the bleaching effect
of the product according to the invention was significantly
better than for the comparative sodium tripolyphosphate-based
product.
A further comparative test was undertaken using the --
formulation of Example 1 to which 0. 62% of proteolytic enzyme
"Alcalase" particles (activity 1 Anson unit) was addea. --
Washing machine evaluation tests showed generally equivalent
performance to a commercially available product containing 35%
of sodium tripolyphosphate with the same enzyme level.
..
Example 2
A powdered high sudsing detergent composition was prepared
to the following nominal formulation:
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Ingredient
Sodium (C -C15) alkyl benzene 20.0
-- sulphona~e
Sodium tripolyphosphate 16.0
Sodium orthophosphate 5.0
Sodium alkaline silicate 10.0
Sodium carbonate 10.0
Sodium sulphate 15 . 5
Borax (lOH20) 14.0
Sodium carboxymethylcellulose 1.0
Fluorescent agents, moisture to 100.0
The above detergent composition was evaluated against a
standard detergent product (B) having a similar formulation
except that the 5% of sodium orthophosphate was replaced by
15 16% of sodium tripolyphosphate to give a conventional level
of 32% o~ the latter material, whilst the amounts of borax and
sodium carbonate were also correspondingly decreased to 5% each
and the level of sodium sulphate increased from 15.5% to 18.5%
in the comparative product (B). In laboratory detergency tests
using soiled cotton vests the light reflectances of the washed
-- garments using the composition of ~xample 2 and comparative ---
product (B), respectively,-were found to be 75% and 80% Of the
light reflectances of the orlginal clean garments, which is not
a signiflcant dlfference. In the same test the fluorescent
agent deposltlon onto the washed garments was also measured and
found to be marginally better for the product accordlng to the
lnventlon. ~he products were also compared ln domestic washing
tests, when lt was found overall that both products were
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acceptable to the users with no significant preference for
either product. This general similarity in detergent
properties was again achieved despite the much lower phosphate
builder level, and consequent lower manufacturing cost, of the
product of the invention.
Example 3
A powdered detergent composition was prepared to the
following nominal formulation:
In~redient ~ -
Sodium alkyl benzene sulphonate 4.0
Tallow alcohol - 18 E0 condensate 4.0
Sodlum tripolyphosphate17.0
Sodium orthophosphate 8.0
Sodium silicate 10.0
Sodium tallow soap 5,0
Sodium hardened tallow soap 3.0
Sodlum perborate 25.0
- Sodium sulphate, waterto 100.0
. This formulation was evaluated in washlng machine tests
witb cotton halved artlcles and found to be equal in overall
detergent performance to a commercially avallable product
contalnlng the same detergent compounds and the sodium hardened
tallow soap but with a much ~igher level of 35~ sodium
trlpolyphosphate as the sole phosphate builder.
.~ , . . . .
-- 25 Examples 4 and 5
- :
: Two powdered detergent compositions were prepared to the
following nominal formulations:
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In~redient Example ~ Example 5
Sodium alkyl benzene sulphonate13.00 i3.00
Sodium tripolyphosphate23.65 9.50
Sodium orthophospbate2.50 6.70
Sodium sulphate 23.60 33.55
Tallow ethanolamide 1.00 1.00
Sodlum toluene sulphonate 0.50 0.50
Sodium carboxymethylcellulose 0.50 0.50
Sodium perborate 19.00 19.00
Fluorescent agents, perfume,to 100.00 to 100.00
moisture
These powders were each produced by spray drying, with
the sodium perborate being added to the spray dried powders,
15 using a slurry temperature of about 70C, a slurry water
content of about 42%~ an air lnlet temperature of about 330C
and an air outlet temperature of about 110C.
The two mixed phosphate products according to the invention _
were evaluated in domestic washing tests against a commercially
20 available product of similar formulation except that it
contained 32% sodium tripolyphosphate as the only phosphate
builder, with a consequent-reduction in the sodium sulphate
level. The overall result of the various attributes assessed
~- by the testers gave no significant preference for any one of the ~ -
, 25 products over the others despite the lower phosphate contents
of the products according to the invention. Detailed analysis
of the results showed slight inferiority in soft water
detergency for the products of the invention, which could be
improved by the addition of about 5% of soap.
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Examples 6 to 11
In order to confirm the compatibili-ty of various detergent
compounds with the mixed phosphate bullder system according to
the invention, a series of detergent formulations were prepared
and tested in testing apparatus sold under the trade mark
~ERG-O-~OMETERS. The amounts of the ingredients used were
as follows:
n~redient %
Detergent compound 10.0
Sodium tripolyphosphate 20.0
Potassium orthophosphate 8.0
Sodium aIkaline silicate 10.0
Sodium sulphate, waterto 100.0
~he results using different detergent compounds were as
follows (using a test procedure with 15 minute wash at 60C
at a product concentration of 0.6% in hard water (25Ca,
5 Mg, French hardness)), which showed good compatibility
. for all the detergent compounds tested.
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Examples 12 and i3
Two detergent compositions were prepared to the following
nominal formulations:
In~redient Example 12Example 13
Sodium alkyl (C -C 5) 8.0 8.0
benzene sulpho~ate
Sodium tripolyphosphate16.0 16.0
Sodium orthophosphate 6.0 6.0
Sodium tallow soap 10.0
Sodium nitrilotriacetate - 10.0
Sodium alkaline silicate10.0 10.0
~:odium sulphate, waterto 100.0to 100.0
These products were evaluated for detergency in a -
Terg-0-Tometer at a product concentration of 0. 6% in soft water
(5H Ca) at 40C. ~he results using artificially soiled test
cloths showed both products to have good detergencies under
these conditions, comparable with a conventional product of
much higher phosphate level (35% sodium tripolyphosphate), and
noticeably better than a similar product which did not contain ,
the added sodium tallow soap or sodium nitrilotriacetate.
Example 14
Two detergent compositions were prepared to the following
nominal formulations:
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In~redient A B
Sodium alkyl benzene sulphonate 15.0 15.0
Sodium tripolyphosphate 15.0 10.0
5 Sodium orthophosphate 5.0 5.0
Sodium pyrophosphate - 5.0
Sodium sulphate, water to 100.0 to 100.0
Pieces of clean cotton terry towelling were washed in 0. 6%
solutions of these products in 40H Ca water at 60C, and then
dried, and then the procedure was repeated up to 20 complete
wash cycles. The levels of inorganic deposits on the fabrics
were determined after 10 and 20 wash cycles by incinerating the
cloths at 600C and weighing the resultant ash. The results
were as follows:
/0 ash
10 washes 20 washes
Product A 0.~9 0.81
Product B 0.90 1.28
These results show that the presence of 5% pyrophosphate
in replacement for 5% of the sodium tripolyphosphate
increased inorganic deposition on the fabric.
Example 15 -~
; A spray dried detergent composition was prepared to the
following nominal formulation:
- 29 -
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In redient
Sodium alkyl (C16-C18) sulpLate 8.0
Sodium tripolyphosphate17.0
Sodium orthophosphate 8.0
Sodium hardened tallow soap 15.0
Sodium alkaline silicate10.0
Sodium perborate 27.0
Sodium sulphate, waterto 100.0
This composition was evaluated against a product with 31%
of sodium tripolyphosphate and found to give superior detergency
in washing machine tests at 0.6% product concentration at both
60C and 90C in 15, 25 and 35 (French) hard water
(Ca:Mg, ~:1).
Example 16 -
A dry mixed powdered high sudsing detergent composition
was prepared to the following nominal formulation:
Ingredient
Sodium linear seC-(cll-cl5) alkyl 16.0
benzene sulphonate
20 Sodium tripolyphosphate 8.0
Sodium orthophosphate 10.0
Sodium alkaline silicate 5.9
Sodium sulphate 3g.0
Water .to 100.0
This product which had a phosphorus content of 4% was
~ evaluated against a comparative product of similar formulation
< except that the sodium orthophosphate was replaced by an
additional 25% of sodium tripolyphosphate, to give a conventional
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total level of 330,b of the latter detergency builder, ie a
phosphorus level of about 8% in the comparative product, with a
consequent decrease in the sodium sulphate level. Detergency
tests were undertaken in Whirlpool Supreme 80 automatic washing
machines using a product concentration of 0.1% at 48C in 8H
water (6 Ca, 2 Mg), when it was found that both products gave
similar overall performance despite the much lower phosphate
level for the product of the invention. When the tests were
repeated at 0.2% there was an overall small preference for the
comparative product with the much higher detergency builder
content.
Further tests were undertaken in which the amounts of
sodium tripolyphosphate and sodium or-thophosphate were changed
to 4% and 15%~ respectively, ie still an overall phosphorus
. . .
content of only 4/Or Comparative detergency tests under the
same conditions then showed a marginal, non-significant ~
preference for the mixed builder product according to the --
invention at 0.1% product concentration, whereas at 0.20k
product concentration the comparative product was preferred.
Examples 17 and 18
Two detergent compositions were prepared to the following
nominal formulations:
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~o
redient Example 17 Example 1
Sodium alkyl (C -C 5) 10.0
benzene sulph~ate
Sec-linear (C -C15) alkyl - - 10.0
9 E0 condensl~te
Sodium tripolyphosphate 5.0 - 5.0
Sodium orthophosphate 15.0 15.0
Sodium alkaline silicate 10.0 10.0
Sodium sulphate, water to 100.0 to 100.0
These products were evaluated in a Terg-0-Tometer detergency
testing apparatus at a concentration of 0.15% in water of 6H
(French hardness 5 Ca, 1 Mg) and 12H (French hardness 10 Ca,
2 Mg) at 40C, against a comparative product of similar
formulation to Example 17 except in having 35% of sodium
tripolyphosphate as the sole phosphate builder. The results
using an artificially soiled cotton polyester test cloth showed
generally acceptable results for all three detergent products
despite the much lower phosphate content of the products of
the invention, but with a small preference for the comparative
product under the soft water conditions. Substantially
- similar detergency results are achieved for all three products
in hard water.
Further tests were done using the same formulations as
; 25 Examples 17 and 18 but with different detergent compounds,
namely, hydroxyalkyl methyl taurine, sodium olefin sulphonate,
sodium (C12-C14)alkyl - 9 E0 sulphate, sodium C16-C18 alkyl
sulphate and lauryl dimethyl ammoniopropane sulphonate. The
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results on washing artificially soiled test cloths under the
same cond~tions as previously except using hard water (25H Ca,
and 5H Mg, French hardness), showed all the detergent compounds
to be compatible with the mixed phosphate builder system, with
the better overall results being achieved using the sodium
(C12-C14)alkyl - 9 E0 sulphate.
Example 19
A spray dried detergent powder was prepared to the
following nominal formulation:
In~redient
Sodium alkyl benzene sulphonate 16.0
Sodium tripolyphosphate14.0
Sodium orthophosphate14.5
Sodium alkaline silicate 8.0
Sodium sulphate, waterto 100.0
This formulation had good physical properties and good
detergent properties at low dosage levels in comparison with
a conventional sodium tripolyphosphate-built product with a
. higher total phosphate content.
.
-
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