Technical Field
[0001] The present invention relates to a liquid bleaching composition comprising a peroxide
bleach. The compositions are useful for a variety of applications. The compositions
are formulated so as to avoid itching of the skin of the user using the composition,
when it comes in contact with the composition.
Background
[0002] Bleaching with peroxygen bleaches is well known in the art. Peroxygen bleaching finds
a variety of applications, such as bleaching fabrics or, in the household, treating
hard surfaces or carpets. A major drawback of liquid peroxygen bleaches is that they
may bleach the skin of the person using the composition and whiten it, if they come
in contact with the composition. This whitening is fully reversible, but it also causes
temporary itching of the skin.
[0003] It is thus an object of the present invention to provide a liquid peroxygen bleach
composition which is formulated so as to avoid this temporary itching phenomenon.
[0004] In response, it has now been found that the itching can be reduced by adding an effective
amount of an anionic surfactant in said liquid peroxygen bleach composition.
Summary of the invention
[0005] Accordingly, in its broadest sense, the present invention is the use, in a liquid
peroxygen bleaching composition, of an anionic surfactant to reduce itching of the
skin of the user of said composition, after it has come in contact with said composition.
[0006] In a preferred embodiment, the invention is a liquid composition formulated as an
emulsion comprising two phases, each phase comprising a nonionic surfactant, said
composition comprising a peroxygen bleach in one of said phases and an activator for
said bleach in the other phase, said composition further comprising an anionic surfactant.
Detailed description of the invention
[0007] The compositions according to the present invention are aqueous. Accordingly, the
compositions according to the present invention comprise from 10% to 95% by weight
of the total composition of water, preferably from 30% to 90%, most preferably from
60% to 80%. Deionized water is preferably used.
[0008] The compositions according to the present invention are stable aqueous emulsions
of nonionic surfactants. By stable emulsion it is meant an emulsion which does not
substantially separate into distinct layers, upon standing for at least 2 weeks at
50 °C.
[0009] Said emulsions of nonionic surfactants comprise at least two nonionic surfactants.
In order to form emulsions which are stable said two nonionic surfactants must have
different HLB values (hydrophilic lipophilic balance), and preferably the difference
in value of the HLBs of said two surfactants is at least 1, preferably at least 3.
By appropriately combining at least two of said nonionic surfactants with different
HLBs in water, emulsions according to the present invention will be formed.
[0010] The advantage of formulating the compositions of the present invention as emulsions
is that a stable activated bleaching compositions can be obtained where the bleach
is present in the more hydrophilic phase, and the activator for said bleach is present
in the other more hydrophobic phase. Such emulsions are described for instance in
EP 92 932.
[0011] Suitable nonionic surfactants for use herein include alkoxylated fatty alcohols.
Indeed, a great variety of such alkoxylated fatty alcohols are commercially available
which have very different HLB values. The HLB values of such alkoxylated nonionic
surfactants depend essentially on the chain length of the fatty alcohol, the nature
of the alkoxylation and the degree of alkoxylation. Hydrophilic nonionic surfactants
tend to have a high degree of alkoxylation and a short chain fatty alcohol, while
hydrophobic surfactants tend to have a low degree of alkoxylation and a long chain
fatty alcohol. Surfactants catalogues are available which list a number of surfactants
including nonionics, together with their respective HLB values.
[0012] The compositions according to the present invention comprise from 2 % to 50 % by
weight of the total composition of said hydrophilic and hydrophobic nonionic surfactants,
preferably from 5 % to 40 %, most preferably from 8 % to 30%.
[0013] The compositions according to the present invention may further comprise other nonionic
surfactants which should however not significantly alter the weighted average HLB
value of the overall composition.
[0014] As an essential ingredient, the compositions herein comprise a peroxygen bleach.
Suitable peroxygen bleaches for use herein are water soluble peroxygen bleach. Preferred
for use herein is hydrogen peroxide, or water-soluble sources thereof such as perborates,
percarbonates, persilicates and persulfate salts.
[0015] Hydrogen peroxide is most preferred for use in the compositions according to the
present invention. Typically, the compositions according to the present invention
comprise from 0.5% to 20% by weight of the total composition of hydrogen peroxide,
preferably from 2% to 15%, most preferably from 3% to 10%.
[0016] By bleach activator, it is meant herein any compound which reacts with hydrogen peroxide
to form a peracid. In the case of bleach activators, such hydrophobic bleach activators
typically belong to the class of esters, amides, imides, or anhydrides.
[0017] Suitable other activators herein must be hydrophobic in the sense that they will
allow segregating said peroxygen bleach in a hydrophilic phase and said bleach activator
in a hydrophobic phase.
[0018] A particular family of bleach activators of interest in the present invention were
disclosed in applicant's co-pending European patent application No 91870207.7. Particularly
preferred in that family is acetyl triethyl citrate which was also disclosed in the
context of bar soaps in FR 2 362 210. Acetyl triethyl citrate has the advantages that
it is environmentally friendly as it eventually degrades into citric acid and alcohol.
Furthermore, acetyl triethyl citrate has a good hydrolytical stability in the product
upon storage and it is an efficient bleach activator. As used herein and unless otherwise
specified, the term bleach activator includes mixtures of bleach activators.
[0019] The bleach activators herein cannot be a compound according to the formulae

in which
- each of Ra and Rb represent hydrogen or a C₁ to a C₅ alkyl radical or a C₂ to C₄ alkenyl radical or
a phenyl radical, Ra and Rb being the same or different or combining together to form a carbocyclic di-radical,
- Rc represents hydrogen or a C₁ to C₅ alkyl radical or a phenyl radical or is combined
with Ra or Rb and the olefin group to form a carbocyclic radical,
- Re represents hydrogen or a C₁ to C₃ alkyl radical or a phenyl radical,
- n is 1 or 2,
- when n = 1, Rd represents hydrogen or a C₁ to C₃ alkyl radical or a phenyl radical,
- when n = 2, Rd represents a C₂ to C₁₀ alkylene di-radical or a phenylene di-radical,
- and m is an integer from 0 to 8, or being one of the corresponding compounds to those
in formula (i) when n = 2 or formula (ii) in which only one of the two enol groups
or carboxylic acid groups, as the case may be, is esterified.
[0020] Formulating the compositions according to the present invention in an acidic pH range
contributes to the stability of the composition. The compositions of the present invention
accordingly have a pH as is of from 0.5 to 6, preferably of from 1 to 5. The pH of
the composition can be trimmed by all means available to the man skilled in the art.
[0021] As discussed hereinafter, when a liquid peroxygen bleach comes in contact with the
skin of the person using it, it causes the itching of the skin. After a while, and
even if the skin is rinsed there develops an irritation of the skin (herein referred
to as itching) which is believed to be caused by the adsorption of the bleach on the
users skin. This adsorption is believed to be induced by the prior adsorption of the
nonionic surfactants herein on the skin.
[0022] The finding underlying the present invention is that anionic surfactants will reduce
or even eliminate the itching which is caused by contact of the bleaching composition
with the skin of the user of the composition. Accordingly, the compositions herein
comprise an anionic surfactant, or mixtures thereof. Suitable anionic surfactants
for use herein include alkyl sulfates, alkyl alkoxylated sulfates and others.
[0023] Suitable alkyl sulfate surfactants for use herein are water soluble salts or acids
of the formula ROSO₃M wherein R preferably is a C₁₀-C₂₄ hydrocarbyl, preferably an
alkyl or hydroxyalkyl having a C₁₀-C₂₀ alkyl component, more preferably a C₁₂-C₁₈
alkyl or hydroxyalkyl, and M is H or a cation, e.g., an alkali metal cation (e.g.,
sodium, potassium, lithium), or ammonium or substituted ammonium (e.g., methyl-, dimethyl-,
and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl-ammonium
and dimethyl piperdinium cations and quarternary ammonium cations derived from alkylamines
such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).
Typically, alkyl chains of C₁₂-₁₆ are preferred for lower wash temperatures (e.g.,
below about 50°C) and C₁₆-₁₈ alkyl chains are preferred for higher wash temperatures
(e.g., above about 50°C).
[0024] Suitable alkyl alkoxylated sulfate surfactants for use herein are water soluble salts
or acids of the formula RO(A)
mSO₃M wherein R is an unsubstituted C₁₀-C₂₄ alkyl or hydroxyalkyl group having a C₁₀-C₂₄
alkyl component, preferably a C₁₂-C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂-C₁₈
alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero, typically
between about 0.5 and about 6, more preferably between about 0.5 and about 3, and
M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium,
lithium, calcium, magnesium, etc.), ammonium or substituted-ammonium cation. Alkyl
ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein.
Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl-ammonium
and quaternary ammonium cations, such as tetramethyl-ammonium, dimethyl piperdinium
and cations derived from alkanolamines such as ethylamine, diethylamine, triethylamine,
mixtures thereof, and the like. Exemplary surfactants are C₁₂-C₁₈ alkyl polyethoxylate
(1.0) sulfate, C₁₂-C₁₈E(1.0)M), C₁₂-C₁₈ alkyl polyethoxylate (2.25) sulfate, C₁₂-C₁₈E(2.25)M),
C₁₂-C₁₈ alkyl polyethoxylate (3.0) sulfate C₁₂-C₁₈E(3.0), and C₁₂-C₁₈ alkyl polyethoxylate
(4.0) sulfate C₁₂-C₁₈E(4.0)M), wherein M is conveniently selected from sodium and
potassium.
[0025] Other anionic surfactants useful for detersive purposes can also be used herein.
These can include salts (including, for example, sodium, potassium, ammonium, and
substituted ammonium salts such as mono-, di- and triethanolamine salts) of soap,
C₉-C₂₀ linear alkylbenzenesulfonates, C₈-C₂₂ primary or secondary alkanesulfonates,
C₈-C₂₄ olefinsulfonates, sulfonated polycarboxylic acids prepared by sulfonation of
the pyrolyzed product of alkaline earth metal citrates, e.g., as described in British
patent specification No. 1,082,179, C₈-C₂₄ alkylpolyglycolethersulfates (containing
up to 10 moles of ehtylene oxide); alkyl ester sulfonates such as C₁₄₋₁₆ methyl ester
sulfonates; acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl phenol
ethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates, isethionates
such as the acyl isethionates, N-acyl taurates, alkyl succinamates and sulfosuccinates,
monoesters of sulfosuccinate (especially saturated and unsaturated C₁₂-C₁₈ monoesters)
diesters of sulfosuccinate (especially saturated and unsaturated C₆-C₁₄ diesters),
acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfates of alkylpolyglucoside
(the nonionic nonsulfated compounds being described below), branched primary alkyl
sulfates, alkyl polyethoxy carboxylates such as those of the formula RO(CH₂CH₂O)
kCH₂COO-M⁺ wherein R is a C₈-C₂₂ alkyl, k is an integer from 0 to 10, and M is a soluble
salt-forming cation. Resin acids and hydrogenated resin acids are also suitable, such
as rosin, hydrogenated rosin, and resin acids and hydrogenated resin acids present
in or derived from tall oil. Further examples are given in "Surface Active Agents
and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants
are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975 to
Laughlin, et al. at Column 23, line 58 through Column 29, line 23 (herein incorporated
by reference).
[0026] Preferred surfactants for use in the compositions herein are the alkyl benzene sulfonates,
alkyl sulfates, alkyl alkoxylated sulfates, and mixtures thereof.
[0027] In order to provide the desired benefit of reducing skin itching, we have found that
the anionic surfactant, or mixtures thereof should be present in a weight ratio of
total anionic surfactant to total peroxygen bleach of from 1 to 10, preferably from
1 to 5, most preferably from 1 to 3. It is believed that this benefit of reducing
skin itching is due to the formation of liquid crystals that limit the adsorption
of the nonionic surfactant on the skin, and as a consequence, adsorption of the bleach.
[0028] Another surprising benefit obtained from the presence of anionic surfactants is that
they act as rheology modifyer in the emulsions according to the present invention.
Indeed, adding anionic surfactants increases the viscosity of the composition and
that is desirable for several reasons, including control of pouring, control for spreading
for instance when the composition is used as a laundry pretreater, cling on vertical
surfaces, when the composition is used as a hard surface treating composition.
[0029] However, adding anionic surfactants above a critical value which depends on the specific
system used leads to phase separation and viscosity collapse. We have found that this
viscosity building effect of anionic surfactants herein also enhances the stability
of the present emulsions at higher temperatures (e.g. above 50°C). Generally, the
compositions herein comprise at most 10% of anionic surfactant.
[0030] The compositions according to the present invention may further comprise a variety
of the ingredients such as perfumes, dyes, optical brighteners, builders and chelants,
pigments, enzymes, dye transfer inhibitors, solvents, buffering agents, radical scavengers
and the like.
[0031] The composition according to the present invention are particularly suitable as laundry
pretreaters, carpet cleaners, or laundry bleach additives. In fact, it appears that
the addition of anionic surfactants improves absorbance of the compositions of the
invention on the fibres. This does not improve pretreatment performance, but gives
significant through the wash performance improvement, particularly on whiteness, dingy
cleaning and enzymatic stain removal.
In its broadest sense, however, the present invention is not limited to the emulsions
compositions of the present invention. Accordingly, the present invention also encompasses
the use of an anionic surfactant, in a liquid peroxygen bleach composition, to reduce
itching of the skin of the user of said compositions when it comes in contact with
said composition.
[0032] The present invention further encompasses a process for the manufacture of the composition
described herein. The process according to the present invention comprises at least
three steps:
[0033] In the first step, a hydrophobic mixture is prepared which comprises the most hydrophobic
nonionic surfactant together with other hydrophobic ingredients which are to be formulated
in the composition, i.e. the bleach activator and optionally as perfumes, solvents,
enzymes, bleach activators and polymers.
[0034] In the second step, a hydrophilic mixture is prepared which comprises at least water,
the more hydrophilic nonionic surfactant. Said peroxygen bleach dyes, optical brighteners,
builders, chelants, hydrogen peroxide and buffering agents. In this second step said
peroxygen bleach is preferably added last, after said buffering agent has been added.
[0035] Naturally, said first and said second steps can be performed in any order, i.e second
step first is also suitable.
[0036] In the third step, both of said mixtures are mixed together.
[0037] The present invention will be further illustrated by the following examples.
EXAMPLES
[0038] The following compositions are made by listing the following ingredients in the listed
proportions
Ingredient |
A |
B |
Dobanol ® 45-7 |
6.0 |
6.0 |
Dobanol ® 91-10 |
3.0 |
3.0 |
Dobanol ® 23-2 |
6.0 |
6.0 |
Alkyl sulfate |
2.0 |
2.0 |
Hydrogen peroxide |
6.0 |
7.5 |
Acety triethy citrate |
3.5 |
7.0 |
Citric acid |
up to pH 4.0 |
up to pH 4.0 |
Minors and deionized water |
balance |
balance |
viscosity 20°C,50rpm) |
700-900 cps |
700-900 cps |
Ingredient |
C |
D |
Dobanol ® 45-7 |
8.0 |
6.7 |
Luthensol ® TO3 |
7.0 |
8.3 |
Na Alkyl sulfate |
2.0 |
2.0 |
Hydrogen peroxide |
6.0 |
7.5 |
Acety triethy citrate |
3.5 |
7.0 |
Citric acid |
up to pH 4.0 |
up to pH 4.0 |
Minors and deionized water |
balance |
balance |
viscosity 20°C,50rpm) |
1000 cps |
2000 cps |
[0039] Furthermore, a test was conducted on 80 panelists to evaluate the skin itching reduction
phenomenon. The panelists were asked to use composition C, with and without Na alkyl
sulfate, as a stain pretreater on fabrics. The panelists therefore used the product
rubbing or spreading it with their fingers. They were asked whether they noticed the
skin itching problem.
[0040] The following results were observed:
Panelist Base: 80 |
composition without NaAS % |
composition with 2% NaAS % |
Noticed skin itching when using the product |
41 |
22 |
Claimed do not like the product because it causes skin itching |
18 |
11 |
[0041] Also, the viscosity buiding effect of anionic surfactants was evaluated by measuring
the viscosity as a function of the amount of anionic surfactant present in the composition.
The following results were observed:
|
Composition C without NaAS |
Composition C with 1.0% NaAS |
Composition C with 2.0% NaAS |
Composition C with 3.0% NaAS |
viscosity (cps) at 20°C at 50 rpm |
800 |
3700 |
5000 |
viscosity collapses with phase separation after 24hrs at room temperature |
viscosity (cps) at 20°C at 3 rpm |
8000 |
47000 |
65000 |
" |
1. The use, in a liquid peroxygen bleach composition, of an anionic surfactant, to reduce
itching of the skin of the user of said composition, wen it has come in contact with
said composition.
2. A liquid peroxygen bleaching composition which is formulated as an emulsion comprising
two phases, each phase comprising a nonionic surfactant, said composition comprising
said peroxygen bleach in one of the phases, and an activator for said bleach in the
other phase, with the proviso that said activator is not a compound according to the
formulae

in which
- each of Ra and Rb represent hydrogen or a C₁ to a C₅ alkyl radical or a C₂ to C₄ alkenyl radical or
a phenyl radical, Ra and Rb being the same or different or combining together to form a carbocyclic di-radical,
- Rc represents hydrogen or a C₁ to C₅ alkyl radical or a phenyl radical or is combined
with Ra or Rb and the olefin group to form a carbocyclic radical,
- Re represents hydrogen or a C₁ to C₃ alkyl radical or a phenyl radical,
- n is 1 or 2,
- when n = 1, Rd represents hydrogen or a C₁ to C₃ alkyl radical or a phenyl radical,
- when n = 2, Rd represents a C₂ to C₁₀ alkylene di-radical or a phenylene di-radical,
- and m is an integer from 0 to 8, or being one of the corresponding compounds to
those in formula (i) when n = 2 or formula (ii) in which only one of the two enol
groups or carboxylic acid groups, as the case may be, is esterified, said composition
further comprising an anionic surfactant.
3. A use or composition according to the preceding claims where said peroxygen bleach
is hydrogen peroxide.
4. A use or composition according to the preceding claims where said hydrogen peroxide
is present in an amount of from 0.5% to 20% by weight of the total composition.
5. A use or composition according to claim 4 where said hydrogen peroxide is present
in an amount of from preferably 2% to 15% by weight of the total composition, most
preferably from 3% to 10%.
6. A use or composition acording to the preceding claims where said anionic surfactant
and said peroxygen bleach are present in a weight ratio of from 1 to 10.
7. A use or composition acording to claim 6 where said anionic surfactant and said peroxygen
bleach are present in a weight ratio of from preferably 1 to 5, most preferably 1
to 3.
8. A use or composition according to the preceding claims where said anionic surfactant
is present in an amount of at most 10% by weight of the total composition.
9. A use or composition according tot he preceding claims wherein said anionic surfactant
is an alkyl benzene sulfonate or alkyl sulfate.