Note: Descriptions are shown in the official language in which they were submitted.
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THICKENED BLEACHING COMPOSITIONS, METHOD OF USE AND
5PROCESS FOR MAKING THEM
20Technical field
The present invention relates to aqueous bleaching compositions, more
particularly to stable acidic thickened aqueous compositions comprising a
25 source of active oxygen. Said compositions find particular application in
the cleaning of hard-surfaces, especially inclined hard-surfaces, such as
toilet bowls and the like.
3 oBackground
A great variety of bleaching and cleaning compositions have been
described in the art. Bleaching/cleaning compositions comprising a source
- 35 of active oxygen and formulated at low pH are particularly interesting for
the cleaning of hard-surfaces, especially for the hygienic cleaning of
sanitary fittings such as toilet bowls and the like.
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Representative of this technical field is, for instancei EP-A-598 694 which
discloses acidic aqueous compositions comprising persulfate salts which
are preferably in the form of an emulsion of nonionic surfactants.
5 However, such compositions have not been found satisfactory as regards
their residence time on the surface to be cleaned in particular if the surface
is wet. Indeed, it is desired to formulate compositions having greater
residence time on non-horizontal surfaces such as inclined wall of a toilet
bowl when applied thereto, allowing thereby that said compositions
10 perform their cleaning action for longer periods of time. There are many
such compositions known in the art that have the requisite viscosity
characteristics. However, most of the thickeners known in the art, whilst
allowing to effectively increase the viscosity of aqueous acidic
compositions, do have some disadvantages in use. Indeed, thickeners like
15 nonionic surfactants (nonyl phenol ethoxylates) or quaternary ammonium
compounds have the disadvantage that they require to be used at high
levels to achieve satisfactory viscosity, thus making them expensive to
use. Also, some thickeners show significant instability in acidic medium,
especially in acidic medium with hydrogen peroxide, or a source thereof,
2 0 like monopersulfate. Indeed, some thickeners are easily oxidizable by
sources of active oxygen, like monopersulfate, in aqueous acidic
compositions, leading thereby to a loss of the total amount of active
oxygen which would otherwise be available to perform bleaching action on
the surface to be cleaned. In other words, some thickeners do not allow
25 to formulate acidic aqueous compositions comprising a source of active
oxygen with salisfactory chemical stability for long storage periods.
It is thus an object of the present invention to formulate acidic aqueous
compositions comprising a source of active oxygen having improved
30 thickening properties.
It is a further object of the present invention to formulate acidic aqueous
compositions comprising a source of active oxygen with high thickening at
low total thickening surfactant level.
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It is another object of the present invention to formulate thickened aqueous
acidic compositions comprising a source of active oxygen which are
chemically stable for long storage periods.
5 It has now been found that the above mentioned objects could be met by
formulating an acidic aqueous composition comprising a source of active
oxygen and, as the thickening system, a quaternary ammonium compound
together with a short chain amine oxide (C6-C10). More particularly, it has
unexpectedly been found that the addition of a small amount of a short
10 chain amine oxide to a quaternary ammonium compound, as the thickening
system, in an acidic aqueous composition comprising a source of active
oxygen allows to formulate highly thickened aqueous acidic compositions
as compared to the use of only said quaternary ammonium compound, as
the thickening system, i.e. a thickening system being free of any short
15 chain amine oxide. Allernali~ely, the present invention allows to use low
level of total thickening surfactant to achieve a given viscosity for an acidic
aqueous composition comprising a source of active oxygen. In other
words, to obtain a desired thickening effect for a given acidic aqueous
composition, a lower level of total thickening surfactants ~quaternary
20 ammonium compounds and short chain amine oxides) is sufficient in the
present invention, as compared to the level of quaternary ammonium
compound which would otherwise be required to obtain the same
thickening effect when used alone, in absence of any short chain amine
oxide. This thickening effect is even more noliceable in the preferred
2 5 compositions of the present invention wherein said source of active
oxygen is a persulfate salt such as monopersulfate salt. Indeed, it has been
found that said persulfate salt together with said quaternary ammonium
compound act as a thickening system.
3 0 It has further been found that the thickening system of the present
invention exhibits good stability in acidic medium and in presence of strong
oxidants like sources of active oxygen. Indeed, the decomposition of said
source of active oxygen, e.g. persulfate salt, is reduced with the thickening
system of the present invention as compared to other surfactant blends
35 like for instance alkylethoxylated alcohols. In other words, sources of
active oxygen in thickened aqueous acidic compositions of the present
invention are chemically stable for longer periods of storage.
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An advantage of the present invention is that the stable thickened aqueous
acidic compositions comprising a source of active oxygen according to the
present invention are less sensitive to the presence of perfumes. Indeed,
5 the thickening system of the present invention allows to formulate stable
acidic aqueous compositions comprising a source of active oxygen and still
having high viscosity, despite the presence of perfumes, even at high
levels. In fact, high levels of perfume are known to have a general
tendency to significantly decrease composition viscosity by changing
10 micellar aggregation.
Another advantage of the present invention is that said stable thickened
aqueous acidic compositions are efficient on various surfaces to clean
15 various soils and stains. Additionally, said compositions when used to
treat hard surfaces, especially toilet bowls, exhibit outstanding soil
discoloration, soil solubilization and emulsification properties together with
a germicidal action, this when used both neat or diluted.
2 0 A further advantage is that the present invention allows to formulate
compositions which are clear, as opposite to clouded, and thus well
accepted from a consumer view point. Also the present invention allows
to formulate cG.nposilions that are Newtonian. By "Newtonian" it is meant
herein a composition which has the same viscosity within a very wide
25 range of applied shear stresses.
In the field of thickened aqueous acidic compositions the following patent
applications are representative of the prior art.
EP-A-275 043 discloses an acidic cleaner for aluminium surfaces
containing a peroxide, acids, a C12-C22 alkyl dimethylamine oxide. Said
cleaner has a pH at most 2. EP-A-275 043 discloses cationic surfactants
as optional ingredients but no specific compounds of this class of
surfactants are mentioned, let alone quaternary ammonium compounds.
EP-A-265 979 discloses acidic thickened aqueous cleaning composition
comprising a disinfecting and/or oxidizing agent, an organic anionic
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sulphonate and a surfactant selected from the group of ( 1 ) quaternary
ammonium compounds wherein at least one of the hydrocarbon groups
linked to the nitrogen is a linear or branched alkyl group containing at least
12 carbon atoms and of (2) tertiary amine oxides wherein at least one of
5 the hydrocarbon groups linked to the nitrogen is a linear or branched alkyl
group containing at least 16 carbon atoms. In contrast, the present
invention uses quaternary ammonium compounds together with short chain
amine oxides ~C6-C10) as the thickening system. Also, nowhere in EP-A-
265 979 a source of active oxygen is disclosed.
EP-A-188 025 discloses aqueous stable thickened low-pH bleaching
compositions comprising an inorganic peroxy compound, a strong acid and
a thickening surfactant. In EP-A-188 025 the thickening surfactant is
selected from (1) amine oxides wherein at least one of the hydrocarbon
15 groups linked to the nitrogen is a linear or branched alkyl group of C6 to
C18 carbon atoms, preferably C12 to C18, ~2) amines and (3) quaternary
ammonium salts wherein at least one of the hydrocarbon groups linked to
the nitrogen is a linear or branched alkyl group of C8 to C18 carbon atoms.
Indeed, EP-A-188 025 teaches to use as a thickening surfactant one of
20 these surfactants. And as rega~s-the amine oxides, this patent application
teaches to preferably use long chain amine oxides. Also none of the
compositions exemplified comprises, as the thickening system, a
quater"ar~/ ammonium compound together with an amine oxide, let alone a
quaternary ~-"."onium cG"")ound together with a short chain amine oxide.
Summarv of the invention
30 The present invention encorr~passes a stable thickened aqueous acidic
bleaching composition comprising a source of active oxygen and, as a
thickening system, a quaternary ammonium compound and an amine oxide
according to the formula R1R2R3N0 wherein R2 and R3 are independently
C1-C4 alkyl groups and wherein R1 is a C6 to C10 alkyl group.
In a preferred embodiment the stable thickened aqueous acidic
compositions of the present invention further comprise a perfume.
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The present invention also encompasses a process of treating hard-
surfaces wherein a stable thickened aqueous acidic composition, according
to the present invention, is used.
The present invention also encompasses a process for the manufacture of
a composition according to the present invention wherein:
- an acidic matrix is prepared which comprises at least water, a
source of active oxygen and an acid,
- then a quaternary ammonium compound is added to said matrix,
- then a perfume, if present, is further added and finally a short chain
amine oxide is added,
- the resulting composition is then stirred over at least three hours.
The present invention further encompasses the use of persulfate salt
together with a quaternary ammonium compound in an aqueous acidic
composition to increase the viscosity of said composition.
Detailed de--scriDtion of the invention
The compositions according to the present invention are stable. By
"stable~ it is meant herein that a composition comprising a source of active
25 oxygen or mixtures thereof, such as persulfate salt, preferably does not
undergo more than 30 % persulfate loss, in six months at room
te""~eral.lre (20~C-25~C). Persulfate concentration can be measured by
titration with potassium permanganate after reduction with a solution
containing ammonium ferrous sulphate. Said stability test method is well
30 known in the art and is reported, for example, on the technical information
sheet of Curox~ commercially available from Interox. Alternatively
persulfate concentration can a~so be measured using a chromatography
method described in the literature for peracids (F. Di Furia et al., Gas-liquid
Chromatography Method for Determination of Peracids, Analyst, Vol 113,
35 May 1988, p 793-795~.
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The compositions according to the present invention comprise, as an
essential element, a source of active oxygen or mixtures thereof. The
source of active oxygen according to the present invention acts as an
oxidizing agent, it increases the ability of the compositions to remove
5 colored stains and organic stains in general, to destroy malodorous
molecules and to kill germs. Suitable sources of active oxygen are
hydrogen peroxide or sources thereof. As used herein a hydrogen peroxide
source refers to any compound which produces hydrogen peroxide when
said compound is in contact with water. Suitable water-soluble inorganic
10 sources of hydrogen peroxide for use herein include persulfate, persulfuric
acid, percarbonates, metal peroxides, perborates and persilicate salts.
In addition, other cl~sses of peroxides can be used as an alternative to
hydrogen peroxide and sources thereof or in combination with hydrogen
peroxide and sources thereof. Suitable classes include dialkylperoxides,
15 diacylperoxide, performed percarboxylic acids, organic and inorganic
peroxides and/or hydroperoxides. Suitable organic
peroxides/hydroperoxides include diacyl and dialkyl
peroxides/hydroperoxides such as dibenzoyl peroxide, t-butyl
hydroperoxide, dilauroyl peroxide, dicumyl peroxide, and mixtures thereof.
20 Suitable preformed peroxyacids for use in the compositions according to
the present invention include diperoxydodecandioic acid DPDA, magnesium
perphthalic acid, perlauric acid, perbenzoic acid, diperoxyazelaic acid and
mixtures thereof.
Persulfate salts or mixtures thereof are the preferred sources of active
25 oxygen to be used in the compositions according to the present invention.
Plefer.~d persulfate salt to be used herein is the monopersulfate triple salt.
One example of monopersulfate salt commercially available is potassium
monopersulfate commercialized by Peroxide Chemie GMBH under the trade
name Curox@). Other persulfate salts such as dipersulfate salts
30 commercially available from Peroxide Chemie GMBH can be used in the
compositions according to the present invention.
The compositions according to the present invention comprise from 0.1%
to 30% by weight of the total composition of said source of active oxygen,
or mixtures thereof, preferably from 0.1% to 20%, and more preferably
35 fromO.1%to 15%.
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Persulfate salts are preferred to be used herein, as-it has been found that
they allow when used together with a quaternary ammonium compound to
increase the viscosity of an aqueous acidic composition. This is especially
noticeable in said aqueous acidic compositions in absence of perfumes.
5 Indeed, it has now been found that the addition of a persulfate salt such as
a monopersulfate salt, as the source of active oxygen, to an aqueous
acidic composition comprising a quaternary ammonium compound such as
C16 trimethyl ammonium methylsulfate improves the viscosity of said
composition as compared to the viscosity of the same composition but
10 without said persulfate salt. It is believed that (HS05-) anion coming from
persulfate salt like monopersulfate salt strongly interacts with the cation
head group of the quaternary ammonium compound displacing its own
counterion (e.g., methylsulfate). It is bclicvcd that the interaction of
persulfate salt like monopersulfate salt with a quaternary ammonium
15 compound plays a significant role in thickening the compositions of the
present invention, together with the thickening effect related to the
addition of short chain amine oxide to said quaternary ammonium
compound.
20 Thus in another aspect, the present invention further encorrpasses the use
of persulfate salt together with a quaternary ammonium compound in an
aqueous acidic composition to increase the viscosity of said composition.
The compositions of the present invention comprise as a further essential
25 01e.,.ent a thickening system. Said thickening system comprises a
quaternary ammonium co" Ipound, or mixtures thereof, together with a
short chain amine oxide, or mixtures thereof.
Suitable qualer"ary ammonium compounds to be used according to the
3 0 present invention are quaternary ammonium compounds wherein one or
two of the hydrocarbon groups linked to nitrogen are a linear or branched
alkyl group of 6 to 30 carbon atoms, preferably of 10 to 25 carbon atoms
and more preferably 12 to 20 carbon atoms, saturated or unsaturated, and
wherein the other hydrocarbon groups (i.e. three when one hydrocarbon
35 group is a long chain hydrocarbon group as mentioned hereinbefore or two
when two hydrocarbon groups are long chain hydrocarbon groups as
mentioned hereinbefore) linked to the nitrogen are independently
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substituted or unsubstituted, linear or branched, alkyl chain of from 1 to 4
carbon atoms, preferably of from 1 to 3 carbon atoms and more preferably
are methyl groups. In the embodiment of the present invention where
persulfate salts or mixtures thereof are used as sources of active oxygen
the quaternary ammonium compound is preferably a non-chloride
quaternary ammonium compound. The counterion used in said quaternary
ammonium compounds are compatible with any source of active oxygen
and are selected from the group of fluoride or methyl sulfate, or
methylsulfonate, or hydroxide and the like.
Particularly preferred to be used in the compositions of the present
invention are trimethyl quaternary ammonium compounds like myristyl
t-i-"t:lt-ylsulfate, cetyl trimethylsulfate a-nd/or tallow trimethylsulfate. Such
trimethyl quaternary ammonium compounds are commercially available
from Hoechst, or from Albright & Wilson under the trade name EMPIGEN
CM~.
The compositions according to the present invention comprise from 0.1%
to 20% by weight of a quaternary ammonium compound, or mixtures
thereof, preferably of from 0.1% to 15%, more preferably of from 0.1% to
10% and most preferably of from 1% to 5%.
Suitable short chain amine oxides to be used according to the present
invention are amine oxides having the following formula R1 R2R3N0
wherein R1 is a C6 to C10 alkyl group, preferably a C8 to C10 alkyl group
and wherein R2 and R3 are independently substituted or unsubstituted,
linear or branched alkyl groups of from 1 to 4 carbon atoms, preferably of
from 1 to 3 carbon atoms and more preferably are methyl groups. R1 may
be a linear or branched alkyl group, being saturated or unsaturated.
Suitable short chain amine oxides for use herein are preferably compatible
with any source of active oxygen. Preferred short chain amine oxides for
use herein are for instance natural blend C8/C10 amine oxide available
from Hoechst.
The compositions according to the present invention comprise from 0.01%
to 15 % by weight of a short chain amine oxide, or mixtures thereof,
-
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preferably of from 0.1% to 10% more preferably of from 0.1% to 5% and
most preferably of from 0.1 % to 3%.
The total level of thickening system, i.e. of quaternary ammonium
compound and of short chain amine oxide, to be used in a given aqueous
acidic composition comprising a source of active oxygen depends on the
thickening desired for said composition, said level being lower than 20%,
preferably between 1% and 15%, more preferably between 1% and 10%
and most preferably between 1 % and 6%.
The compositions of the present invention have a viscosity of more than
250 cps at 20~C, preferably of from 250 cps to 1500 cps and more
preferably of from 250 cps to 900 cps, when measured with a Brookfield
viscometer at 60 rpm with a spindle n~ 2 or with the Carri-med rheometer
at 50 dyne/cm2.
Furthermore, the stable thickened aqueous acidic compositions of the
present invention comprise a quaternary ammonium compound and a short
chain amine oxide, as the thickening system, the weight ratio of said short
chain amine oxide to said quaternary ammonium compound being from 1 :2
to 1:100, preferably from 1:4 to 1:30 and more preferably from 1:10 to
1:20.
In an embodiment of the present invention the compositions as described
hereinbefore further comprise a perfume or mixtures thereof . It is well
known that perfumes have a general tendency to significantly decrease the
viscosil~ of cG,~posilions in which they are introduced. An advantage of
the thickened acidic compositions of the present invention is, that they are
less sensitive to the presence of perfume, even the presence of high levels
of perfumes. Suitable perfumes to be used herein are all the perfumes well
known in the field per se or blend of such perfumes.
The compositions according to the present invention comprise up to 3% by
weight of the total composition of a perfume or mixtures thereof,
preferably of from 0.1 % to 2% and more preferably of from 0.2% to 1 %.
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The compositions of the present invention are acidic compositions. In
order to obtain appropriate stability of the source of active oxygen in the
compositions according to the present invention, said compositions are
formulated at a pH between 0 to 6, more preferably at a pH between 0 and
5 4 and most preferably at a pH between 0 and 2. Acidity further contributes
to formulate compositions according to the present invention which exhibit
good limesc~le removing performance while having also good disinfecting
properties. Accordingly, the compositions of the present invention further
comprise organic and/or inorganic acids. Particularly suitable organic acids
10 to be used herein are aryl and/or alkyl sulfonate, such as methane sulfonic
acids, citric acid, succinic acid, sulphamic acid and the like. Particularly
suitable inorganic acids are sulfuric, phosphoric, nitric acids and the like.
15 The compositions according to the present invention are aqueous. The
compositions according to the present invention comprise from 40% to
99% by weight of the total composition of water, preferably from 60% to
95%, most preferably from 70% to 90%. Deionized water is preferably
used.
As an optional but highly preferred ingredient the co,-"~ositions according
to the present invention further comprise an alkali metal sulphate or
mixtures thereof. Plefer,ed alkali metal sulphates to be used herein include
~,olassium sulphate, sodium sulphate or mixtures thereof. We have now
25 found that the addition of an alkali metal sulphate in the compositions of
the present invention comprising persulfate salt such as monopersulfate
salt, as the source of active oxygen, improves the chemical stability of said
compositions. Indeed the percentage of monopersulfate lost upon storage
time in a liquid composition according to the present invention comprising
30 a given amount of monopersulfate and an alkali metal salt of sulphate is
reduced as compared to the percentage of monopersulfate lost upon
storage time in the same composition but without said alkali metal
sulphate. Monopersulfate concentration can be measured as already
defined herein before. It is believed that the addition of an alkali metal
35 sulphate stabilises monopersulfate salts by shifting the following
equilibrium to the left hand side:
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H20+KHS04+KHS05 - K2S04+H2S04+H202
Accordingly the compositions according to the present invention comprise
up to 10% by weight of the total composition of said alkali metal sulphate
5 or mixtures thereof, preferably from 1% to 10% and more preferably from
2% to 7%.
In another aspect, the present invention further encorr~passes the use of an
alkali metal sulphate in an aqueous composition comprising a persulfate
10 salt, preferably monopersulfate salt to improve the chemical stability of
said composition.
Depending on the end use envisioned, the compositions according to the
present invention may further comprise a variety of other ingredients
15 including other surfactants of all types to boost the performance over a
wider range of soils/encrustations, organic or inorganic alkalis, dyes,
optical brighteners, builders, chelants, pigments, enzymes, dye transfer
inhibitors, solvents, buffering agents, stabilizers and the like.
2 0 The present invention further encompasses a process of treating hard-
surfaces, especially non-horizontal surfaces, wherein a composition
according to the present invention is used in its neat or diluted form.
By "in its diluted form" it is meant herein that said compositions may be
25 diluted with water up to 99% of water. Said dilution may occur either
before, after or while said composition is applied to a hard-surface.
The co"-posiliGns herein find a preferred application in the cleaning of toilet
bowls and bath tubs. While cleaning toilet bowls compositions according
30 to the present invention may be diluted while or after they are applied to
the surface to be cleaned. For example, said compositions may be
dispensed from a container onto said hard-surface, then diluted in water
and left to act onto said surfaces, then removed by rinsing or flushing.
35 As used in the foregoing paragraphs, the expression "treating" includes
washing as the compositions used in the process according to the present
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invention comprise surfactants and bleaching agents as said compositions
also comprise a source of active oxygen, preferably persulfate salts.
The compositions according to the present invention may be manufactured
5 by adding the different ingredients in any order. However, the desired
initial viscosity of an aqueous composition Df the present invention is
obtained immediately, when following a preferred mixing order for the
incorporation of the different ingredients in said composition. Accordingly,
the present invention further encompasses a process for the manufacture
10 of the compositions of the present invention, wherein said process
comprises the steps of:
- preparing an acidic matrix comprising at least water, a source of active
oxygen and an acid,
- adding to said matrix the quaternary ammonium compound,
15 - then adding the perfume if present and finally the short chain amine
oxide,
- and as a final step the resulting composition is stirred over at least three
hours.
20 The present invention is further illusl(ated by the following examples.
Example I
Compositions are made which comprise the listed ingredients in the listed
25 proportions (weight %).
C~ osili~.. s #1 #2 #3 #4 #5
C16 t,imell,yl ammonium 4.0 4.2 5.0 0.0 0.0
methylsulfate
C16/18 I,i",ell,yl 0.0 0.0 0.0 4.0 4.0
ammonium methylsulfate
C8/C10 amine oxide 0.2 0.0 0.0 0.2 0.0
Curox~9 ~ 6.0 6.0 6.0 6.0 6.0
Methane sulfonic acid 5.0 5.0 5.0 S.0 5.0
Perfume 0.7 0.7 0.7 0.7 0.7
Water and mlnors up to 100
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14
pH
Initial viscosity~ (cps) 300 20 300 960 30
Appearance clearnot clear clearnot
clear clear
Rheological Behaviour Newt.Pseud. Newt. PseudNewt.
Curox~9 is one of the commercial names of monopersulfate salts
~Viscosity grows with time; therefore, those are the lowest achievable
viscosities with the above indicated compositions.
The initial viscosity of the above compositions were measured by a Carri-
Med Rheomoter at fixed shear stress (50 dyne/cm2) at 20~C. It has been
chosen a standard value of the shear stress to compare the viscosity of the
above mentioned compositions, some of which showing a pseudoplastic
10 behaviour. 50 dyne/cm2 as shear stress value is representative of a fluid
flow occurring on a inclined surface when the product thickness is around
1mm and the only external force is due to the gravity field as per toilet
cleaning application.
Compositions #1 and #4 are representative of the stable thickened
aqueous acidic compositions according to the present invention, i.e. they
comprise a quaternary ammonium compound and a short chain amine
oxide as the thickening system. Compositions #2, #3 and #5 are taken as
20 reference, they are free of short chain amine oxides.
The above data surprisingly show that the addition of a small amount of a
short chain amine oxide (0.2% by weight) to a quaternary ammonium
25 compound (4% by weight) in an acidic composition comprising a source of
active oxygen, like monopersulfate, allows to formulate a composition
having a higher viscosity as compared to the same composition wherein
the thickening system used is only a quaternary ammonium compound.
(See composition #1 with a viscosity of 300 cps versus composition #2
30 with a viscosity of 20 cps as well as composition #4 with a viscosity of
960 cps as compared to composition #5 with a viscosity of 30 cps).
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Also the above data show that the addition of a small amount of short
chain amine oxide (0.2% by weight) to quaternary ammonium compound
(4% by weight) in an acidic composition comprising a source of active
5 oxygen, like monopersulfate, allows to decrease the level of total
thickening surfactant needed to formulate an aqueous acidic composition
with a desired viscosity as compared to the use, as a thickening system, of
a quaternary ammonium compound alone without any short chain amine
oxide (see composition #1 with a level of 4.2% of thickening system
10 according to the present invention versus composition #3 with a level of
5% of thickening system in order to obtain compositions having the same
viscosity, i.e. 300 cps). In other words, the present invention allows to
formulate thickened aqueous acidic compositions at low total level of
thickening surfactants, i.e. to achieve the same viscosity, the thickening
15 system of the present invention used in composition #1 allows a reduction
of 16% by weight of the total level of thickening surfactant needed as
compared to the level required with composition #3 .
2 0 The data also show that the compositions according to the present
invention were clear compositions, as opposite to clouded (i.e. not clear)
compositions and Newtonian compositions.
ExamDle ll
Compositions are made which further illustrate the present invention and
30 which comprise the listed ingredients in the listed proportions (weight %).
ComDositions #1 #2 #3 #4 #S
C16 trimethyl ammonium 4.00 4.00 4.00 4.00 4.00
methylsulfate
C8/C10 amine oxide 0.00 0.00 0.30 0.30 0.30
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Curox~) } 6.00 6.00 0.00 6.00 4.00
Sulfuric acid 6.00 6.00 4.00 6.00 6.00
Perfume 0.00 0.70 0.70 0.70 0 70
Water and minors Jp to 10 ~
pH < 2 < 2 < 2 < 2 < 2
Initial viscosity~' ~cps) 5000 <50 50 300 250
Appearance clear cloud clear clear clear
Rheological Behaviour Newt. Pseud. Newt. Newt. Newt.
~ Curox~) is one of the commercial names of monopersulfate salts
*~Viscosity grows with time; therefore, those are the lowest achievable
5 viscosities with the above indicated compositions.
The initial viscosity of the above compositions were measured by a Carri-
Med Rheomoter at fixed shear stress ~50 dyne/cm2) at 20~C. It has been
10 chosen a standard value of the shear stress to compare the viscosity of the
above mentioned compositions, some of which showing a pseudoplastic
behaviour. 50 dyne/cm2 as shear stress value is representative of a fluid
flow occurring on a inclined surface when the product thickness is around
1mm and the only external force is due to the gravity field as per toilet
15 cleaning application.
Co,-")ositions #1 and #2 are taken as reference, they are free of short
chain amine oxides. Composition #3 is taken as reference, it is free of
20 monopersulfate salt. Compositions #4 and #5 are representative of the
stable thickened aqueous acidic compositions according to the present
invention, i.e. they comprise a quaternary ammonium compound, a short
chain amine oxide and monopersulfate salt.
The above data surprisingly show that the addition of a monopersulfate
salt to a acidic aqueous composition comprising a short chain amine oxide
and a quaternary ammonium compound allows to formulate a composition
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having a higher viscosity as compared to the same composition but
without said monopersulfate salt. (See compositions #4 and #5 comprising
respectively 6% and 4% by weight of the total composition of
monopersulfate salt with a viscosity of respectively 300 cps and 250 cps
5 as compared to composition #3 without monopersulfate salt and with a
viscosity of 50 cps). Also the aboYe data show the correlation between the
increase of the concentration of monopersulfate salt and the increase of
viscosity in said matrix.
The above results further show that the present invention allows to
formulate thickened aqueous acidic compositions at low total level of
thickening surfactants, even if perfume is present, by combining
monopersulfate, quaternary ammonium compound and short chain amine
15 oxide.
ExamDle 111
Compositions are made which further illustrate the present invention and
which comprise the listed ingredients in the listed proportions (weight %).
ComDositions #1 #2 #3 #4
C16 ~ hyl ammonium 4.70 5.00 5.70 7.00
methylsulfate
C81C10 amine oxide 0.36 0.38 0.44 0.54
Curox~ ~ 6.00 6.00 6.00 6.00
Methane sulfonic acid 5.00 5.00 5.00 5.00
Perfume 0.7 0.7 0.7 0.7
Sodium sulphate 5.00 5.00 5.00 5.00
Water and minors up to up to up to up to
100 100 100 100
pH ~ 2 < 2 < 2 ~ 2
Initial viscosity (cps) 370 400 800 1400
Appearance clear clear clear clear
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CA 02204~07 1997-0~-0
WO 96/17044 PCT/US9S1154g5
¦ Rheological Behaviour ¦ Newt. ¦ Newt. ¦ Newt. ¦ Newt. ¦
ExamDle IV
ComDositions #1 #2 #3 #4 #5 #6
C16 trimethyl ammonium 4.00 4.00 4.00 4.004.00 4.00
methylsulfate
C8/C10 amine oxide 0.30 0.10 0.30 0.300.30 0.30
Curox~ * 6.00 6.00 6.00 6.006.00 6.00
Methanesulfonic acid 10.00 15.00 0.00 0.005.00 0.00
Sulfuric acid 0.00 0.00 3.00 6.006.00 0.00
Phosphoric acid 0.00 0.00 0.00 0.000.00 12.00
Perfume 0.70 0.70 0.70 0.700.70 0.70
Water and minors up to 100
pH 0.66 0.35 1.00 0.78 0.50 1.00
Initial viscosity ~cps) 270 330 380 400 300 320
Appearance clear clear clear clear clear clear
Rheological Behaviour Newt. Newt. Newt. Newt. Newt. Newt.
5 * Curox~ is one of the commercial names of monopersulfate salts.
All the above mentioned acidic aqueous compositions comprising
monopersulfate provide significant benefits in toilet soils cleaning both
when used neat or diluted. Said compositions were found to be stable
10 over lon~ periods of time. Indeed, these compositions had not more than
~ 10% loss after 1 month at room temperature.
