Note: Descriptions are shown in the official language in which they were submitted.
~Z~4~
DETERGENT FO~M CONTROL AGENTS
This invention is concerned with foam control
agents and with detergent compositions comprising these
foam control agents.
Detergent compositions in powder form are used or
washing purposes in machines for washing dishes or for
laundering of textiles. These compositions generally
contain organic surfactants, builders, for example phos-
phates, bleaching agents and various organic and
inorganic additives. The surfactants usually employed in
domestic textile washing powders when agitated in an
aqueous medium during a washing cycle tend to yield
copious quantities of`foam. ~Iowever, presence of excess-
ive amounts of foam during a washing cycle in certain
washing machines tends to adversely affect the quality of
the wash.
It has become a practice to include in detergent
compositions materials which are intended to control the
amount of foam produced during a washing cycle. Various
materials have been proposed for this purpose, including
for example certain silicone antifoams. Silicone anti-
foams, especially those based on polydimethylsilo~anes,
~ave been found to be particularl.y useful foam controll-
ing agents in various media. ~owever, generally silicone
antifoams, when incorporated ln detergent compositions in
powder form , appear to lose their effectiveness after
prolonged storage in the detergent compositions.
G.B. Patent Specification 1 l~07 997 is directed to
detergent composit-Lons which contain as an essential
ingredient a silicone suds controlling agent which is
stable on storage. It discloses detergent compositions
including a suds controlling component comprising a
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silicone suds controlling agent and silica or a solid
adsorbent releasably enclosed in an organic material
which is a water soluble or water dispersible, substan-
tially non-surface active, detergent-impermeable carrier
material e.g. gelatin, agar or certain reaction products
of tallow alcohol and ethylene oxide. British S~iflca~ion No.
1 ~07 997 states that the carrier material contains with-
in its interior substantially all of the silicone suds-
controlling agent and effectively isolates i-t from, i.e.
keeps it out of contact with, the detergent component of
the compositions. The carrier material is selected such
that, upon admixture with water, the carrier matrix
dissolves or disperses to release the silicone material
incorporated therein to perform its suds-controlling
function.
Whilst these materials are satisfactory in many
respects it is desirable to enhance the range o~ mate-
rials which may be used to provide storage stable anti-
foam containing detergent compositions in powder form.
G.B. Patent Specification 1 523 957, which relates
to detergent compositions containing a silicone foam con-
trolling agent, discloses a powdered or granular deter-
gent composition containing from 0.5 to 20% by weight of
a foam control substance which comprises powdered or
granular sodium tripolyphosphate, sodium sulphate or
sodium perborate having on the surface thereof an organo-
polysiloxane antifoam agent, which is at least partially
enclosed within an organic material which is a mixture of
a water insoluble wax having a melting point in the range
from above 55C to below lOO~C and a water-insoluble
emulsifying agent. We. have found that the storage stabi-
lity of the exemplified detergent compositions disclosed
in G.B. Patent Specification 1 523 ~57 though better than
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that of detergent compositions where the silicone foam
controllin~ agen~ is replaced by an organopolysiloxanc
antifoam agent on its own, is not always satisfactory
especially when storage occurs at 40C over a longer
period of time. It is also desirable to reduce ~he
number of those constituents of the foam controlling
agent which contribute lit~le or no beneficial effect to
the detergent composition when used in a wash cycle.
It is an object of the present invention to provide
an improved silicone based foam control agent which is
suitable for use in a detergent composition in the form
of a inely divided powder and is capable of retaining
its foam controlling qualities during storage of the
detergent composition.
It is also an object of the present invention to
provide a Eoam control agent for inclusion in a detergent
composition in powder form, wherein the number of mate-
rials used ~o retain the foam controlling ability of the
silicone antifoam is kept to a minimum.
We have now found that foam control agents which
retain their foam controlling properties during storage
in a detergent composition may be wax ree and comprise a
silicone antioam and certain organic materials.
The invention provides, in one of its aspects, a
particulate foam control agent in finely divided form for
inclusion in a detergent composition in powder form,
characterised in that the agent is wax-free and comprises
a silicone antifoam and an organic material having a melting
point ln the range 50 to 35C and comprising a monoester
of glycerol and a fatty acid having a carbon chain
containing from 12 to 20 carbon atoms.
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By the expression wax-free, where used herein, we
mean that the foam control agent does not contain any
monoesters of long chain unbranched fatty acids (C24 to
C36) and alcohols (C16 to C36).
A foam control agent according to the invention
is in finely divided form and comprises discrete elements
which may be mixed with a detergent composition in powder
form in quantities of about 0.1 to 25% by weight of the
composition and distributed throughout the composition.
During storage at ambient atmosphere conditions at room
temperature and at temperatures up to about the melting
point of the organic material these discrete elements
comprise the organic material and the silicone antifoam.
The organic material is selected for its ability to
preserve sufficient of the activity of the silicone anti-
foam during storage and until required to perform its
antifoam function during a washing cycle. Whilst not
wishing to be bound by any particular theory, we believe
that the organic material acts as a binder or coating to
preserve the constitution and disposition of at least a
substantial proportion of the discrete elements during
storage of the foam control agent in admixture with the
detergent composition in powder form. The binder effect
of the organic material is unaffected by heating to
temperatures lower than its melting point. However, the
organic material when heated to a temperature equal to or
higher than its melting point becomes liquid and no
longer detnonstrates the binder effect, thus permi~ting
the previously bound silicone antifoam to be released.
The organic material has a melting point in the
range 50 to 85C. The organic material may comprise a
single compound which has a melting point in that range,
or a mixture of compounds which has a melting point in
2~4~4
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that range. Organic materials having a melting point of
50C or more are chosen in order that the foam control
agent may be stable under routine conditions of storage
and transportation of a detergent composition in powder
form containing it. During summer months, or in warmer
countries, during transport or storage the ambient
temperature can easily rise to 40C or more. Also, many
housewives store the container of the detergent composi-
tion in a room where heat is often produced and tempera-
tures could be in excess of 40C. Organic materialshaving a melting point of 85C or less are selected in
order to ensure that any silicone antifoam which remains
bound by the organic material when the detergent composi-
tion is used in a washing cycle is released at a useful
stage in that washing cycle in order to control foaming.
Organic materials suitable for use in a foam con~
trol agent according to the invention comprise monoesters
oE glycerol and certain fatty acids. Particularly suit-
able are those organic materials which are at least to
some extent water dispersible. Preferred materials
include monoesters of glycerol and aliphatic fat~y acids
have a carbon chain containing 12 to 20 carbon atoms.
Examples of such materials, which are all water
insoluble ! include glyceryl monolaurate, glyceryl monomy-
ristate, glyceryl monopalmitate and glyceryl mono~stearate. More preferred organic materials suitable for
use in a ~oam control agent according to the invention
comprise glyceryl monostearate. These materials are
pre~erred because o~ thelr good perEormance, easy avail-
ability, degree of water dispersibility and suitablemelting point. Glyceryl monostearate, having in its pure
~orm a melting point of 82C (~ ester) or 74C (~-ester),
is commercially available in different grades which are
~ 7 ~45
believed to comprise mi~tures of -the monoester, diester
and triester alongside some free glycerol and free
stearic acid. Glyceryl monostearate is also available as
a non-emulsifying or a self-emulsifying material. The
self-emulsifying glyceryl monostearate comprises also a
certain amount of soap. A most preferred organic mate-
rial for use in a oam control agent according to the
invention comprises glyceryl monostearate (self-
emulsifying). This material is believed to comprise
about 30% by weight of the glyceryl monostearate and
about 5% by weight of a soap as well as mixtures of
diesters and triesters and has a melting point of about
about 58C. Glyceryl monostearate (self emulsifying) is
water dispersible at its melting point of 58C. Although
glyceryl monostearate is surface active it does not
appear to interfere with the effectiveness of the sili-
cone antifoam when it is released into the washing
liquor.
It is advantageous to provide foam control agents
in which not all the silicone antifoam is fully bound, as
this appears beneficial to the control of foaming of the
detergent composition in the early stage of the wash
cycle i.e. before the binding effect of the organic mate-
rial has been fully disrupted during the washing cycle.
In this way one may ensure that sufficient antifoam is
available in the early part of the washing cycle for the
antifoam to perform its function of controlling the foam
level at this stage. This is desirable because excessive
foam, even though only present during a part o~ the wash
cycle, usually results in a decrease of the laundering
eficiency of the surfactants, due to for example reduced
agitation.
12~45
The amount of organic material employed ln a :Eoam
control agent according to the invention is chosen so
that when the foam control agent has been added to a
detergent composition the composition remains stable
upon storage. It is, however, desirable to keep the
amount of organic material to a minimum because it is not
expected to contribute to the cleaning per~ormance of the
detergent composition during a washing cycle. It is also
desirable that it is removed from the laundered materials
for example with the washing liquor, without causing
unacceptable soiling or greying of the laundered
materials e.g. through soil redeposition. The amount of
organic material employed is best calculated in a weight
to weight ratio of organic material to silicone antifoam.
A foam control agent according to the invention may suit-
ably comprise organic material in a ratio of from 5:1 to
1:1 by weight of the silicone antifoam. Preferably the
ratio is from 2:1 to 2.5:1. Ratios below 1:1 may give
both manu~acturing problems and storage stability
problems, while ratios above 5:1 do not seem to contri-
bute any benefit over those obtained at a ratio 5:1 and
are commercially less attractive. Nevertheless, it is
expected that ratios above 5:1 will work equally well.
A foam control agent according to the invention
comprises a silicone antifoam. By the expression sili-
cone antifoam, where used herein, we mean an antifoam
compound comprising a polydiorganosiloxane and a solid
silica. The polydiorganosiloxane is suitably substan-
tially linear and may have the average formula
R R
R_ -SiO- - Si-R
R n R
where each R independently can be an alkyl or an aryl
~ 7~S
radical. Examples of such su~stituents are methyl,
ethyl, propyl, isobutyl and phenyl. Preferred polydior-
ganosiloxanes are polydimethylsiloxanes having trimethyl-
silyl endblocking units and having a viscosity at 25C of
from 5 x 10 5 m2/s to 0.1 m2/s i.e. a value of _ in the
range 40 to 1500. These are preferred because of their
ready availability and thelr relatively low cost. The
solid silica of the silicone antifoam can be a fumed
silica, a precipitated silica or a silica made by the
gelformation technique. The silica particles suitably
have an average particle size of from 0.1 to 50 ~, pref-
erably from 1 to 20 ~ and a surface area of at least 50
m2/g. These silica particles can be rendered hydrophobic
by treating them with dialkylsilyl groups and/or trial-
kylsilyl groups bonded directly onto the silica or bymeans of a silicone resin. We prefer to employ a silica
the particles of which have been rendered hydrophobic
with dimethyl and/or trimethyl silyl groups. Silicone
antifoams employed in a foam control agent according to
the invention suitably have an amount of silica in the
range of 1 to 30% (more preferably 2 to 15%) by weight of
the total weight of the silicone antifoam resulting in
silicone antifoams having an average viscosity in the
range of from 2 x 10 4 m2/s to 1 m2/s. Preferred sili-
cone antifoams may have a viscosity in the range of from5 x 10 3 m2/s to 0.1 m2/s. Particularly suitable are
silicone antifoams with a viscosity of 2 x 10 2 m2/s or
4.5 x 10-2 m2/S
Foam control agents according to the invention may
be made by any convenient method which enables contacting
the silicone antifoam and the organic material in their
liquid phase. The conven-tional procedures for making
powders are particularly convenient e.g. spray drying and
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fluid bed coating procedures. For example the organic
material in liquid form and the silicone antifoam in
liquid form may be passed into a tower and permitted to
form the foam control agent. In one method the silicone
antifoam and the organic materlal are sprayed simulta-
neously into a spray cooling tower. Upon spraying, sma]l
liquid droplets are formed containing the silicone anti-
foam and the organic material. The droplets cool down as
they make their way down the tower. Thus they solidify,
forming a particulate finely divided foam control agent
according to the invention. The silïcone antifoam and
the organic material may be mixed prior to spraying, or
by contacting the sprayed liquid droplets of both
materials, for example by spraying the materials via
separate nozzles. The finely divided Eoam control agent
is then collected at the bottom of the tower. Solidifi-
cation of the droplets may be encouraged, for example by
use of a cool air counterstream, thus reducing more
quickly the temperature of the droplets. If desired,
other ingredients of a detergent composition or component
thereof may be passed into the tower e.g. in advance of
the organic material and silicone antifoam, so that the
foam control agent formed includes carrier particles
formed from those ingredients. We prefer to produce the
foam control agent by contacting the organic material and
the silicone antifoam in their liquid form and passing
them onto a fluid bed in which are suspended solid
carrier particles. The oam control agent formed
includes carrier particles from the Eluid bed. These
carrier particles may comprise any suitable materi.al but
conveniently may be an ingredient or component part of a
detergent composition. The carrier particles utilised in
the ~oam control agent provide a solid basis on which the
~ Z ~ 5
silicone antifoam and the organic material may be depo-
sited and thus provide a dry basis for the silicone anti-
foam, so that the foam control agent may be a ~ree
flowing powder at room temperature and therefore can be
easily mixed into a detergent composition in powder form.
The carrier particles also bulk up the foam control agent
to facilitate the dispersibility of the foam control
agent in the powder detergent. Even distribu~lon of the
agen~ in the detergent composition is important since it
is desirable that every unit-measure of the detergent
composition used by the housewife contains sufficient
foam control agent to stop excessive foam formation even
though the foam control agent may be employed at levels
below 1% by weight of the total detergent composition.
Preferably the carrier particles are of water soluble
solid powder material which facilitate dispersion of the
silicone antifoam in the aqueous liquor during the wash
cycle. However, other materials which do not chemically
bond with the silicone antifoam may also be used as
carrier particles. It is most suitable to choose carrier
particles which themselves play an active role in the
laundering or washing process. Examples of such
materials are zeolites, sodium sulphate, sodium carbo-
nate, carboxymethylcellulose and clay minerals. Such
materials are useful as builders, soil suspenders,
di].uents, softeners etc. in the detergent composition.
Preferred carrier particles for use in a foam control
agent according to the invention are selected with a view
to avoiding settling of the foam control agent to the
bottom of a container of detergent composition. Most
preferred carrier particles comprise sodium ~ripolyphos~
phate (STPP) particles. STPP is preferred because it has
a low bulk density of around 0.5 g/cm3, is water soluble
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and does not appear to interfere ~ith the ef~ectiveness
of the silicone antifoam~ A foam control agent according
-to the invention may comprise carrier particles in an
amount of from ~0 to 90% by weight based on the total
weight of the ioam control agent. We prefer to use 70 to
~0% of carrier particles by weight of the total foam
control agent.
The invention provides in another of its aspects a
method of making a particulate wax free foam control
agent in finely divided form for inclusion in a detergent
composition in powder form characterised in that silicone
antifoam and an organic material having a melting point
in the range 50 to 85C and comprising a monoester of
glycerol and a fatty acid having a carbon chain
containing from 12 to 20 carbon atoms, are contacted
together in their liquid phase and are caused -to form a
solid in admixture.
In a preferred method according to the invention
the silicone antifoam and the organic material are mixed
and heated to a temperature above the melting point of
the organic material. They may be heated to such tempe-
rature before, during or after the mixing stage. The
temperature is chosen sufficiently high, for example
90C, so that the transport from the mixi.ng and/or heat-
ing vessel ~o a spray unit does not cause this tempera-
ture to fall below the melting pOillt of the organic
material. Any conventional mixing method may be used for
the mixing of the silicone antifoam and the organic
material for example paddle ~tirring or ribbon blending.
The heated mixture may then be transferred under pressure
to a spray nozzle. This can be achieved by any conven-
tional pumping system, but preferably a peristaltic pump
is used as this avoids any possible contamination of the
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mixture with materials from the pump. The pumping rate
may vary and can be adapted to the type o~ spray unit
used. The mixture may suitably be pumped at a rate of
for example 1.4 x lO 6 m3/s. The spray nozzle and
spraying pressure are chosen such that the liquid drop-
lets which are formed are small enough to enable even
distribution in a detergent composition. The liquid par-
ticles can then fall and deposit themselves in admixture
onto a fluid bed of a carrier material, such as the
preferred STPP. A foam control agent according to the
invention is then collected when the mixture has been
sprayed onto the carrier particles.
Foam control agents according to the present inven-
tion employ a novel combination of ingredients and enable
production of storage stable detergent compositions in
powder form without resort to water-soluble or water-
~ispersible substantially non-surface active, detergent
impermeable materials and without the need for adding a
water insoluble wax.
Foam control agents according to the invention do
not appear to give rise to deposits of the organic mate-
rial upon textiles laundered with detergent compositions
containing these foam control agents in amounts suffi-
cient to control the foam level during laundering opera-
tions. An additional advantage of the preferred foam
control agents according to the invention is that the
amount of organic material introduced into a detergent
composition is still acceptable even when a relatively
large amount of silicone antifoam is used in the deter-
gent composition.
The present invention also provides a detergentcomposition in powder form, comprising a detergent compo-
nent and a foam control agent according to the invention.
4~9LS
A foam control agent according to the invention may
be added to the detergent component in a proportion of
from 0.1 to 3% by weight based on the total detergent
composition weight if no carrier particles are included
in the foam control agent. The preferred foam control
agents, which include carrier particles, may be added in
a proportion of from 0.25 to 25% by weight based on the
~o~al de~ergent compo~ition weigll~.
Suitable detergent components comprise an ac~ive
detergent, organic and inorganic builder salts and other
additives and diluents. The active detergent may comp-
rise organic detergent surfactants of the anionic,
cationic, non-ionic or amphoteric type, or mixtures
thereof. Suitable anionic organic detergent surfactants
~Le alkali metal 80~ of higher r~" ~y nci~8, ~lkyl ~Iryl
sulphonates, for example sodium dodecyl benzene sulpho-
nate, long chain (fatty) alcohol sulphates, olefine sul-
phates and sulphonates, sulphated monoglycerides, sulpha-
ted ethers, sulphosuccinates, alkane sulphonates, phos-
phate esters, alkyl isothionates, sucrose esters andfluorosurfactants. Suitable cationic organic detergent
surfactants are alkyl-amine salts, quaternary ammonium
salts, sulphonium salts and phosphonium salts. Suitable
non-ionic organic surfactants are condensates of ethylene
oxide with a long chain (fatty) alcohol or fatty acid,
for example C14l,15 alcohol., condensed with 7 moles of
ethylene oxide (Dobanol l~5-7), condensates of ethylene
oxide with an amine or an amide, condensation products of
ethylene and propylene oxides, fatty acid alkylol amldes
and fatty amine oxides. Suitable amphoteric organic
detergent surfactants are imida~oline compounds, alkyl-
aminoacid salts and betaines. Examples of inorganic com-
ponents are phosphates and polyphosphates, silicates,
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such as sodium silicates, carbonates, sulphates, oxygen
releasing compounds, such as sodium perborate and other
bleaching agen~s and zeolites. Examples of organic comp-
onents are anti-redeposîtion agents, such as carboxy
methyl cellulose (CMC), brighteners, chelating agents,
such as ethylene diamine tetraacetic acid (EDTA) and
nitrilotriacetic acid (NTA), enzymes and bacteriostats.
Materials suitable for the detergent component are well
known to the person skilled in the art, and are described
in many text books, for example Synthetic Detergents,
A. Davidsohn and B.M. Milwidsky, 6th edition,
George Godwin (1978).
The ~ollowing examples are selected to illustrate
the invention by way of example. All parts and percent-
ages are expressed by weight unless otherwise stated.
l. Foam control agent production.
All example foam control agents were prepared bystirring 50g of a silicone antifoam into molten organic
material. The mixture thus formed was heated to 85 or
90C. This hot liquid mixture was then pumped with a
peristaltic pump, via a heat-traced transport line, to
the spray head of a fluid bed 'Aeromatic' coating equip-
ment, where it was sprayed at a pressure of 1.2 x 105 Pa
through a no~.le of l.lmm at a rate of 1.~2 x 10 6 m3/s
onto a fluid bed of 500g o STPP (Albright and Wilson,
Marchon division). The STPP was kept in the fluid bed by
an air pressure at a relative setting of 8 to 10. When
all the mixture was sprayed onto the STPP a particulate
example foam control agent according to the invention was
collected.
Details of the composi~ion (in parts) of each of
the example foam control agents are given in Table I.
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TABLE I
Exam~le Foam Control Agents
Ingredients 1 2 3 4 5 6 7 8
AF A 5
S AF B 5 5 5 5
AF C 5 5 5
OM l 12 12 25 12
OM 2 12
OM 3 12
OM 4 12
OM 5 12
AF A was a silicone antifoam consisting of a
mixture of polydimethylsiloxanes and about 13% by weight
of the antifoam of hydrophobic silica. Antifoam A had a
viscosity at 25C of about 2 x 10 2 m~/s.
AF B was a silicone antifoam consis~ing of a
mixture of polydimethylsiloxanes and about 4.5% by weight
of the antlfoam of hydrophobic silica. Antifoam B had a
viscosity at 25C of about 4.5 x 10 2 m2/s.
AF C was a silicone antifoam consisting of a
mixture of polydimethylsiloxanes and about 5% by weight
of the antifoam of hydrophobic silica. Antifoam C had a
viscosity at 25C of about 2 x 10 2 m2/s.
OM 1 was glyceryl monostearate (self-emulsifying)
GE*0~02 s/e from Croda Chemicals Limited, which is
believed to comprise about 30% glyceryl monostearate, a
maximum of 7~ free glycerine, about 5% soap and a maximum
of 2% water. It had a saponiication value of about 152
to 160 and a melting point of about 58C.
OM 2 was glyceryl monostearate GE 0803 (n/e) from
Croda Chemicals Limited, which is believed to comprise
about 30% glyceryl monostearate, a maximum of 5% free
glycerine and a maximum of 2% water. It had a saponifi-
cation value of about 165 to 175 and a melting point of
about 58C.
* Trademark
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*
OM 3 was glyceryl monostearate GE 3546 (n/e) from
Croda Chemicals Limited, which is believed to comprise
about 90% glyceryl monostearate, a maximum o 1% free
glycerine and a maximum of 2% water. It had a saponi~i-
cation value of about 150 to 165 and a melting point of
about 65C.
OM 4 was glyceryl monomyristate Grindtek MM 90 from
Grindsted Products A/S 9 which is believed to comprise a
minimum o~ 90~ glyceryl monomyristate, a maximum of 4%
free glycerol, a maximum of 5% of glyceryl monolaurate
and of glyceryl monopalmitate. It had a saponification
value of about 180 to 190 and a melting point of about
65C.
OM 5 was glyceryl monolaurate Grindtek ~L 90 from
Grindsted Products A/S, which is believed to comprise a
minimum of 90% glyceryl monolaurate, a maximum of 4% free
glycerol, a maximum of 5% of glyceryl monocaprate and of
glyceryl monomyristate. It had a saponification value of
about 200 to 210 and a melting point of about 56C.
2. Storage stability testing.
A detergent composition was prepared by mixing 9
parts sodium dodecyl benzene sulphonate, 4 parts Dobanol
45-7, 40 parts sodium tripolyphosphate and 25 parts
sodium perborate. This composition is regarded as a
basis for a detergent powder composition which may be
made up to 100 parts with other ingredients, for example
diluents, builders and additives; as these ingredients do
not usually tend to contribute significantly to the foam
generation o~ the composition they were not included in
the detergent test composition.
The detergent test composition was divided in lots
of 78g to which the foam control agent was then added and
mixed in, in proportions sufficient to give, based on the
* Trademark
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weight o~ the detergent test composition, the level of
silicone antifoam mentioned in Table II or Table III in
ord~r to provide sample detergents. Sample detergents 1,
2, 3, 4, 5, 6, 7 and 8 contain respectively first,
second, third, fourth, fifth, sixth, seventh and eighth
example foam control agent. Also first and second compa-
rative detergents were prepared consisting of 78g o~ the
detergent test composition and the silicone antifoam AF A
and AF B respectively, as referred to hereinabove in
proportions mentioned in Table II.
In a ~irst test method a convelltional au~omatic
washing machine (Miele 427) of the front loading type
having a transparent door through which clothes may be
loaded to the machine was loaded with 3.Skg of clean
cotton fa~ric. A wash cycle with a prewash and a main
wash (95C) was carried out using one lot of sample
detergent for each of the prewash and the main wash, each
lot containing 78g of the detergent test composition.
The door of the washing machine was divided in its height
by a scale from 0 to 100% with 10% intervals. The level
of the top of the foam during the wash cycle was compared
with the scale after about 40 minutes of the main wash,
when the temperature had reached 90C, when the rotation
drum of the washing machine was stationary and the scale
values were recorded.
In a second test method a conventional automatic
~ 11*
washing machine (Miele W 433 de lu~e) was used which had
a more severe agitation than the machine used in the
first test method. This means that a larger amount o
foam was generated than in the first method. The test
was carried out as in the first method apart from the
fact that the prewash was left out.
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Sample detergents l, 2, 3, 5 and 6 and first and
second comparative detergents were tested according to
the first test method while sample detergents 4, 7 and 8
were tested according to the second test method.
One set of sample detergents or comparative deter-
gents was tested immediately after admixture of the foam
control agent or of the silicone antifoam to the deter-
gent test composition (initial test), and a second set
was stored in closed glass containers at 40C for 30 days
be~ore testing (test after storage). The results are
recorded in Tables II and III.
TABLE II: FIRST TEST METHOD
FOAM HEIOEIT RECORDED (%)
% Si-Antifoam Initial Test After
15 Detergents Added Test Storage
Comparative 0.19 20%
detergent 1 0.26 NIL Overflow
(9 min) *
Sample 0.19 60% 70%
detergent 1 0.26 30% 70%
0.32 NIL 30%
Comparative 0.19 30%
25 detergent 2 0.26 NIL Overflow
(7 min) *
Sample 0.19 40% 20%
detergent 2 0.26 NIL 10%
0.32 NIL NIL
Sample 0.19 30% 20%
detergent 3 0.26 NIL NIL
0,32 NIL NIL
,..... ... .. .
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Sample 0.19 NIL 30%
detergent 5 0.26 NIL NIL
Sample 0.19 10% ~10%
5 detergent 60.26 NIL NIL
-~ By overflow we mean that the foam came out of the
washing machine through a vent at the top. The time at
which this occurred, measured from the beginning of the
prewash, is given in between brackets.
TABLE III: SECOND TEST METHOD
FOAM HEIGHT RECORDED %
Detergents % Si-~ntifoam InitialTest After
Added Test Storage
Sample 0.19 50%
detergent 4 0.26 30% 100%
0.32 50% 50%
0.38 - 25%
Sample 0.26 100%
detergent 7 0.38 25% 100%
0.51 30% 75%
Sample 0.26 100%
detergent 8 0.38 40% 100%
0.51 30% 35%
As can be seen from -the results shown in Tables II
and III the compositions contalning a foam control agent
according to the invention retain a slgn-Lficant propor-
tion oE their foam control ability a-fter prolonged
storage.
