Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1~13829
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FA~RIC WASHIN~.COMPOSI~IO~S CON~AINING A~IONIC
AND NON-ANIONIC SURFAC~AN~S I
~his in~en~ion relates to wa~hing composition~.
~here are now a number of constraint~ on the
formulation of wa~hing ~ompo~ition~. ~he~e inalude the '! ' '
intended u~e, whi¢h influences product form, and legal .: .
re~triction~, which may influence phosphoru~ content and
also the processing route taken. At a mare detailed level,
e~en after it ha~ been decided that a particular
composition is to be aimed at the fabric washing market,
consideration~ as to whether the main use is to be in hand- .
washing, in twin-tub or in automatic (front lo~ding) wa~hing
machine~, con~train the formulation options. For instance,
it is now widely recognised that the amount of suds
acceptable in a front-loading washing machine is
considerably les~ than that required in a top-loading twin-
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tub machine and a suitable low sudsing formulation must be
produced for this market.
~ he practical effect of these constrai~ts has been to
narrow the possible range of commercially acceptable
formulations, but this has placed a premium on optimisation
of particular compositions from the possible field in order
to obtain best performance.
We have now discovered that very good detergenc~ and a
suds level substantially higher than that produced by a low
sudsing formulation can be obtained at relatively high
concentrations of free calcium if the detergent active
species consists of a mixture of a calcium sensitive
anionic surfactant and a Cll 24 alcohol alkox~late in which
the proportion of the alcohol.alkoxylate is limited.
Accordingly, the pre~ent invention provides a high
~uds fabric washing powder comprising a weak detergency
builder as herein defined, characterised by the detergent
active apecies being a mixture consisting of from 20 to 2~/o
by weight of the powder of a calcium sensitive anionic
s.urfactant and from 1 to 3% by.weight of the powder of a
Cll 24 alcohol alkoxylate contai~ing from 5 to ~0 mole~ Or
' ethylene oxide or from 5 to 30 mole~ of a mix~ure of
ethylene oxide and propylene oxide, per mole of alcohol,
the presence of the Cll 24 alcohol alkoxylate serving to
increa~e the detergency of the powder in use.. '.'
~ he term 'weak detergency builder' as u~ed herei~
mean~ a compound or mixture o~ compounds which, when the
fabric wa~hing powder i~ di~olved at.a given concentration
in water of given hardnes~, leaves a sufficient free
30. calcium ion concentration in bhe solution for the calcium
~alt of the anionic surfactant to be precipitated, were it
not ~or the presence of the nonionic surfactant. ~hat is
to say, that if the nonionic surfactant is omi~ted from
the powder'formulation, the calcium ~alt of the ~nionic '.'
detergent active is precipitated. However, because ~pray-
dried powders normally produce a cloudy solution and`
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1113~Z9
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because some of the modern detergency builders are
precipitant builders (such as orthophosphates) or are in
any ca~e incompletely dissolved in the wash liquor
(alumino silicates) it is not a simple matter to tell
whether a precipitate of the calcium salt of the anionic
surfactant is being formed.
In practice, the best way of determining this is to
perform a detergency test since this provides a direct
measure of the effect of precipitation on the performance
of the wa~hing powder.
Consequently, in order to determine whether the builder
system in a particular formulation is a weak builder as
herein defined, and hence whether that formulation fall~
within the scope of this application, it is necessary to
perform te~ts to asse~s the detergency of the formulations
in the absence of nonionic surfactant at a number of
different concentrations of water hardness. ~rom the~e
tests it is within the competence of a chemist skilled in
the detergents art to extrapolate the concentration and
water hardnés~ at which the calcium salt of the anionic
surfactant is beginning to be precipitated.
A weak detergency builder-is defined aæ one which
permits prqcipitation of the calcium salt of the anionic
surfactant from water containing 300 ppm of water hardne~
ions, calculated as calcium ¢arbonate, at a product
concentration ~f 2 gm~
Preferably, the powder contains no more than 5% by
weight of phosphorus.
Examplqæ of calcium senæitive surfactants are salts,
preferably sodium salts of C9 16 linear or branched alkyl
benzene sulphonate~, Cl~ 22 primary alkyl sulphates or
C16 22 æecondary alkyl sulphates, and mixtures of C13 20
5econdar~ alkane gulphonateæ or C12 22 vinylidène olefine
~ulphonates and hydroxy alkane sulphonates. Of these, the
preferred mRterials are alkyl benzene sulphonates having
an average of 12 or 13 carbon atomæ in the alkyl subætituent,
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1~:138Z9
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C14_17 or C16_19 secondary alkane sulphonates and C14 20
primary alkane sulphates.
Satisfactory detergency properties æe obtained at as
little as 20% by weight of the anionic surfactant, based
on the total composition, and even better ones when the
minimum level is treated as 22%. ~he anionic surfactant
content cannot be increased indefinitely, since when
using amounts of nonionic surfactant of between l and 3%~
as proposed above, processing difficulties set in when the
anionic surfactant reaches 30-32%~ depending on the water
content of the crutcher slurry and also higher levels of
nonionic surfactant substantiaIly reduce the amount of foam
produced. ~hus, whilst the invention extends to compositions
containing between 20 and 30% of the calcium sensitive
15 anionic surfactant, it is preferred that the range should
be 22 to 27%. Particularly good results are obtained when
the level is 24.5 to 25.5% with a level of nonionic
surfactant of from 1.5 to 2.5% by weight.
As has been mentioned already, the formulations of the
invention are preferred to contain a maximum of 5% by weight
of pho~phoru8. ~his i8 believed to be the level to which
future legislation will settle. In our experienc.e, at
phosphorus levels of 5% or les8 in hard water, the free
calcium ion concentration in hard water will often be high
25 enoùgh to precipitate calcium sensitive.anionic surfactants
in the abse~ce of steps to pre~ent that.
~he detergenc~ builders which may be used in the ..
compositions of this invention may be any of the ~equestrant
or precipitant builders which have been suggested to replace
phosphate builders, or they may be phosphate salts, or
mixtures of any one of the~e, generally in amounts ~rom
10 to 30/0 by weight in the case of phosphate builders and
10 to 35% by weight in the case of non-phosphat`e.ones.
Examples of detergency builders which ma~ be used are.
ortho-, pyro- and tripolyphosphatesf aluminosilicates;
carbonates? especially the sodium carbonate/calcium
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carbonate combination; polyphosphonates such as ethane-l-
hydroxy-l,l-diphosphonate; amine carboxylates such as
nitrilotriacetates and ethylene diamine tetra acetates;
ether carboxylates such as oxydiacetates, oxydisuccinates,
carboxymethyloxysuccinates and malonates; citrates;
mellitates; and salts of polymeric carboxylic acids such
as polymaleates, polyitaconates and polyacrylates. These
salts will normally contain alkali metal or ammonium cations,
preferably sodium.
Mixtures of sodium ortho- and tri-polyphosphate are the
preferred detergency builders, particularly mixtures in the
ratio 10:1 to 1:5, preferably 5:1 to 1:1 tripolyphosphate
to orthophosphate, in amounts of 10 to 30% by weight.
~he nature of the nonionic surfactant is not especially
critical in the compositions of this invention provided tha~
it conforms to the definition given earlier, that is it is
an ethoxylate, or mixed éthoxylate/propoxylate of a Cll 24
alcohol containing from 5 to 30 moles per mole of alcohol,
of alkylene oxide.
~he alcohol may be straight chain or branched chain,
primary or secondary and may be made by one of the synthetic
processes, such as the 'Ziegler' or 'Oxo' processes, or may
be derived from naturally occurring materials such a~
tallow.
~he alkoxylation may be carried out by conventional
means using from 5 to 30, pr~ferably 15 to 25 and most
preferably 15 to 20 moles of ethylene oxide, or a mixture
of ethylene oxide and propylene oxide in the de~ired
proportions which will depend on the degree of hydrophobic
character required.
Examples of commercially available materials which
are ~uitable for use in this invention are:
~ ergitols (~rade Mark) which are a series `of
ethoxylates of secondar~ alcohols sold by the Union Carbide
Corporation, especially ~ergitol 15-S-7, 15-S-9, 15-S-12
and 15-S-15 which are ethoxylates of a mixture of C11 15
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alcohols and ~ergitols 45-S-12 and ~5-S-15 which are
ethoxylates of a mixture of C14 and C15 alcohols, the degree
of ethoxylation being shown by the postscript.
~thoxylates of primary alcohols made by the Oxo process
5 and containing about 20% of alpha branched material sold by
Shell Chemicals Ltd and Shell Chemicals Inc as Dobanols and
~eodols (registered Trade Marks) respectively, especially
Dobanol and ~eodol 25-7, 25-9, 25-12 and 25-15 which are
ethoxylates of a mixture of C12-C15 alcohols and Dobanol
10 45-7, 45-9, 45-12 and 45-15 which are ethoxylates of a
mixture of C14_15 alcohols-
Ukanils (~rade Mark) which æe a series of ethox~latesof Oxo alcohols containing about 25% of alpha methyl
branched and about 10% of ethyl branched material and
15 Acropols (~rade Mark) manufactured by Ugine Euhlman et Cie,
especially Acropol 35-7, 35-9, 35-11 and 35-15 which are
derived from a mixture of C13-C15 alcohols^
Synperonics (~rade Mark), a series of ethoxylates of
alcohols containing 45-55% of alkyl branchin~, mostl~ methyl
branching, sold by Imperial Chemical Industries Limited,
especially those based on a C13 15 mixture of alcohols and
ethoxylated to 7,9,11 and 15 units of ethylene oxide.
~ thoxylates of primary Ziegler alcohols sold as AIfo~s
(~rade Mark) derived by polymerisation of ethylene,
manufactured by Cono~o-Condea, especiall~ Alfol 12/14-7,
12/14-9, 12/14-12, 12/14-15 and Alfol 14/12-7, 14/12-9,
14/12-12, 14/12-15 which are ethox~lates of mixtures of
C12 and C14 alcohols, Alfol 16/18-10, 16/18-18 and
16/18-25, and Alfol 16/20-10, 16/20-18. and 16/20-25 which
are ethox~lates of mixtures of C16 and C18 alcohols and
mixtures of C18 and C20 alcohols respectively.
Ethoxylates of primary O~o alcohols containing about
60% branched material, sometimes called Lials ~rade Mark)
produced from olefins manufactured by ~iquichimica.
~astly, ethoxylates of natural alcohols, such as tallow
alcohol can be used.
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Other conventional components of detergent compositions
may be present in conventional amounts. Examples of these
include powder flow aids such as finely divided silicas and
aluminosilicates, antiredeposition agents such as sodium
5 carboxymethylcellulose, oxygen-releasing bleaching a~ents :-
such as sodium perborate and sodium percarbonate, per-acid
bleach precursors such as tetraacetylethylenediaminé,
chlorine-releasing bleaching agents such as trichloroiso-
cyanuric acid and alkali metal salts of dichloroisocyanuric .
acid, fabric softening agents such as clays of the smectite
and illite types, anti-ashing aids, starches, slurry
stabilisers such as copolyethylene maleic anhydride and
copolyvinylmethylether maleic anhydride, usually in salt
form, inorganic salts such as ~odium silicates and sodium
sulphate, and usually present in very minor amounts,
fluorescent agents, perfumes, enzymes such as proteases and
amylases, germicides and colourants. lhe detergent
compositions usually have an alkaline pH,.generally i~ the
region of pH 9-11, which is achieved by the presence of
alkaline salts, especially sodium silicates such as the
meta-, netural or alkaline silicates, preferably at levels
up to about 15% by weight~ - .
~ h0 invention will be further described in the
following Examples.
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~xample 1
% by welght
Component A B
Sodium C12 alkyl benzene sulphonate 20.0 27
5 ~allow alcohol ethoxylate (25 ~0) 7
Sodium tripolyphosphate (STPP)13.6 13.6
~risodium orthophosphate 5.0 5.0
Alkaline sodium silicate 9.0 10.0
Sodium sulphate 25.3 31.9
10 Coloured STPP speckles 3.0 ~.0
Sodium polyacr~late 3.0 3.0
Enzymes 1.2 1.2
Water & minor ingredients to 100 to 100
~hese two formulations were mixed in various
proportions in order to obtain fabric washing powders
containing amounts of nonionic surfactant var~ing from
0 to 7% of the powder. ~he suds performance o~ the
resultant powder was then assessed using a Ross-Miles
dynamic foam meter, which is an instrument-well known in
the detergents art. (~he results are shown in ~able l).
~ he time taken for the lather to collapse was also
measured. -
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1~38Z9
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N O O O 0
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~13829
- 10 - cC.1028
As can be seen from the ~able, products containing
more than 3% nonionic surfactant had a suds stability of
less than 5 minutes, which is considered unsatisfactory.
~he detergency of some of the products obtained by
mixed ~ormulations A and B was also tested. A handwashing
procedure was used and the detergency was assessed using-a
reflectance method. ~he results are shown in ~able 2.
Table 2
R460 Reflectance (proportional to detergency)
2.5 gms/l produc.t,.concentration.in..water..of..30.
hardness f~rench~ '.
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. % nonionic. . 0 1. . 3 7
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/0 a,nionic 27 26, 24 20 . ~ .
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ER~C" 42.3 49.3 . 53.2 55.0 .'
. . AS 12+ ," 47-9, 50.2 52.1 53-8 ¦ , .. .
- It can be seen that there is a general trend towards
increasing detergency with increasing percentage of . ~ -
nonionic surfactant. ~he difference between the deterge,ncy
of the composition containing 26% by weight of anionic and
. 1% by weight of ~onionic surfactant and that of the ,~
composition.containing no nonionic surfactant at all i9
more substantial than the differen¢e between the
compo~ition~ containing 3 and ~/o of nonio~ic surfactant
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respectiVel~. .
'~A cotton test piece soiled with a ~ynthetic sebum ,: .
and inorganic materials. , -.
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~A cotton test piece soiled with an organic. ,
synthetic soil.
~he conclusion to be drawn from these two~experiments ;~
is that there is a heavy fall-off in foaming powe~ when . -
the amount of nonionic surfactant ~eaches 3%, but that
detergency increases rapidly with additions of ver~ small
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amounts of nonionic surfactant, increasing more slowl~ -
therea~ter. ~he op-timum of .oaming and detergency appears
to be reached at 25% alkyl benzene sulphonate and 2% tallow
alcohol ethoxylate, acceptable levels being obtained at
24% and 3% respectively.
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