Technical field
[0001] The present invention relates to a liquid bleach additive composition, which can
be used to bleach fabrics in conjunction with a conventional particulate or liquid
laundry detergent.
Background of the invention
[0002] Commonly encountered liquid bleaching compositions suitable for the bleaching of
stains on fabrics are based on halogen bleaches, especially hypochlorite bleaches,
or peroxygen oxygen bleaches such as hydrogen peroxide.
[0003] Halogen bleaches are extremely effective bleaching agents, however they also present
a number of drawbacks which can sometimes dissuade a consumer from choosing the halogen-containing
product. For example halogen bleaches, especially chlorine bleaches, emit a pungent
odor during and after use (e.g., on consumer hands and/or surfaces treated therewith)
which some consumer find disagreeable.
[0004] Furthermore, it is known in the art that halogen bleach-containing compositions (typically
hypochlorite) are relatively aggressive to fabrics and may cause damage when used
in relatively high concentration and/or repeated usage. In particular the consumer
may perceive damage to the fabric itself (e.g. loss of tensile strength) or damage
to the color intensity of the fabric. While color and fabric damage may be minimized
by employing milder peroxygen bleaches such as hydrogen peroxide, the bleach performance
characteristics of such peroxygen bleaches are much less desirable than those of the
halogen bleaching agents.
[0005] Therefore, liquid bleaching compositions comprising pre-formed peroxy carboxylic
acid have been developed. It has been found that such bleaching compositions comprising
pre-formed peroxy carboxylic acid show a good bleaching performance, when used in
laundry applications, especially as so-called bleach additives, and are also safe
to fabrics and/or colors. Indeed, peroxy carboxylic acids are known in the art, for
example from EP-A-0 435 379. Furthermore, the use of such peroxy carboxylic acid to
treat fabrics has been described in the art, e.g., in WO 00/27963, WO 00/27964, WO
00/27965, WO 00/27966, WO 00/27967, WO 00/27977 and WO 2002/12431.
[0006] It has been found that chemical stability of currently known peroxy carboxylic acid-based
bleach additives was below expectations. In addition, preformed peroxy carboxylic
acids represent a challenge to be handled at bleach additives manufacturing plants.
[0007] These difficulties have recently been overcome with the use of imido-type peroxy
acids, which being solids are safer to be handled at manufacturing plants, and can
also be stabilized into liquid bleach additive formulations by suspending them as
solid particles. A specific class of imido-type peroxy acids are of imido-type peroxy
alkanoic acids, especially phthalimido peroxy alkanoic acids, and in particular ε-phthalimido
peroxy hexanoic acid (PAP).
[0008] However, given their chemical structure, imido-type peroxy acids when present in
bleach additives are not stable upon use at the pH of the wash liquor formed by conventional
particulate laundry detergents. By "bleach additives" it is meant herein, a composition
that is used in conjunction with, this means added to the washing machine together
with, a conventional laundry detergent, in particular a particulate laundry detergent,
in a laundry washing operation.
[0009] Usually, conventional particulate laundry detergents (like ARIEL powder) provide
a pH in the wash above 9.5. The imido moiety of the peracid hydrolyzes quantitatively
and irreversibly at such a pH (as described in REINHARDT, G. 1994b: Imidoperoxicarbonsäuren
als potentielle Bleichmittel für die Waschmittelindustrie. SÖFW-Journal 120: 411-416).
This leads to a hydrophilic molecule, which has been observed to provide bleaching
performance of the wash liquor per-se in the washing machine (formed by the laundry
detergent, the bleach additive and water) rather than stains on fabrics being washed
in the washing machine. Indeed, currently known imido-type peroxy acids-based bleach
additives failed to provide adequate bleaching performance on stains when used in
combination with particulate detergents. This effect is not or at least to an insignificant
extent observed in so-called pretreater bleaching compositions comprising imido-type
peroxy acids, wherein the pretreater is applied onto the fabric prior to the washing
or rinsing and left to act thereon for an effective amount of time.
[0010] It is thus an objective of the present invention to provide a liquid bleach additive
comprising an imido-type peroxy acids, which delivers effective bleaching performance
on stained fabrics, when used in conjunction with a conventional particulate laundry
detergent.
[0011] It has now been found that the liquid bleach additives comprising an imido-type peroxy
acid and a source of protons according to the present invention meets the above objective.
[0012] An advantage of the compositions of the present invention is that the liquid bleach
additives herein are suitable for the bleaching of different types of fabrics including
natural fabrics, (e.g., fabrics made of cotton, and linen), synthetic fabrics such
as those made of polymeric fibres of synthetic origin (e.g., polyamide-elasthane)
as well as those made of both natural and synthetic fibres. For example, the liquid
bleach additives of the present invention herein may be used on synthetic fabrics
despite a standing prejudice against using bleaches on synthetic fabrics, as evidenced
by warnings on labels of clothes and commercially available bleaching compositions
like hypochlorite-containing compositions.
[0013] Another advantage of the liquid bleach additives according to the present invention
is that they can be used in a variety of conditions, i.e., in hard and soft water.
[0014] Yet another advantage of the compositions of the present invention is that they exhibit
also effective stain removal performance on various stains including enzymatic stains
and/or greasy stains.
Summary of the invention
[0015] The present invention encompasses a liquid bleach additive composition having a viscosity
of up to 5000 cps and/or comprising at least 50% by weight of the total composition
of water, and additionally comprising an imido-type peroxy acid and a source of protons
having at least one acidic moiety donating protons in water at a pH below 7.5, wherein
said composition comprises at least 0.80 mmoles of protons available at pH below 7.5
per gram of composition.
[0016] The present invention further encompasses a kit comprising at least two compositions,
wherein a first composition comprises an imido-type peroxy acid and optionally a source
of protons having at least one acidic moiety donating protons in water at a pH below
7.5, and wherein a second composition comprises a source of protons having at least
one acidic moiety donating protons in water at a pH below 7.5, wherein said compositions
when combined comprise at least 0.80 mmoles of protons available at pH below 7.5 per
gram of mixed compositions.
[0017] Furthermore, the present invention encompasses a process of treating fabrics which
comprises the steps of forming an aqueous bath comprising water, a conventional laundry
detergent, preferably a particulate laundry detergent, and a liquid bleach additive
composition according to the present invention, and subsequently contacting said fabrics
with said aqueous bath.
[0018] Moreover, the present invention encompasses a process of treating fabrics which comprises
the steps of forming an aqueous bath comprising water, a conventional laundry detergent,
preferably a particulate laundry detergent, and a liquid bleach additive composition
formed by the at least two compositions of the kit according to the present invention,
and subsequently contacting said fabrics with said aqueous bath.
[0019] Furthermore, the present invention encompasses the use of a source of protons having
at least one acidic moiety donating protons in water at a pH below 7.5, in a liquid
bleach additive composition comprising an imido-type peroxy acid, wherein said composition
comprises at least 0.80 mmoles of protons available at pH below 7.5 per gram of composition
to provide effective bleaching performance on stained fabrics, when used in conjunction
with a conventional particulate laundry detergent.
Brief description of the drawings
[0020]
Figure 1 is a plot showing the a titration curve of an average wash solution formed
by a conventional particulate laundry detergent. Indeed, 110 grams of ARIEL® granular
detergent were dissolved in 12 liters of water, which represents the recommended dosage
of a granular detergent in a washing machine (under European washing conditions),
and titrated with a composition comprising 10% of citric acid and 90% of water. The
plot shows the pH of the wash solution versus the concentration of protons coming
from the citric acid-containing composition.
Detailed description of the invention
The liquid bleach additive composition
[0021] The liquid bleaching compositions herein are so-called liquid bleach additive compositions
suitable for use in conjunction with a conventional laundry detergent, and in particular
with particulate laundry detergents, to treat (stained) fabrics. The terms "additive"
or "through-the-wash (bleaching) composition" refer to compositions that are preferably
employed in the specific process of treating, preferably bleaching, fabrics as encompassed
by the present invention.
[0022] Indeed, additive compositions are added together with a conventional laundry detergent
(preferably particulate laundry detergent) into a washing machine and are active in
the same wash-cycle. By contrast, so-called 'spotter' or 'pretreater' compositions
that are applied, mostly undiluted, onto fabrics prior to washing or rinsing the fabrics
and left to act thereon for an effective amount of time. Furthermore, so-called 'soakers'
or 'rinse-added' compositions are contacted, mostly in diluted form, with fabrics
prior or during rinsing of fabrics with water.
[0023] The compositions according to the present invention are liquid compositions as opposed
to a solid or a gas. The liquid bleach additive compositions have a viscosity of up
to 5000 cps at 20 s
-1 and/or comprise at least 50% by weight of the total composition of water.
[0024] The liquid bleach additive compositions preferably have a viscosity of up to 5000
cps at 20 s
-1, more preferably from 5000 cps to 50 cps, yet more preferably from 2000 cps to 50
cps and most preferably from 1200 cps to 50 cps at 20 s-
1 and 20°C when measured with a Carri-Med Rheometer model CSL
2 100® (Supplied by TA Instruments) with a 4 cm conic spindle in stainless steal (linear
increment from 0.1 to 100 sec
-1 in max. 8 minutes). The liquid bleach additive compositions are preferably not pasty
or paste-like compositions.
[0025] Alternatively or additionally (preferably additionally), the liquid bleach additive
compositions comprise at least 50%, preferably from 50% to 95%, more preferably 70%
to 95%, even more preferably 75% to 95% by weight of the total composition of water.
[0026] Preferably, the pH of the compositions according to the present invention is from
0.1 to 6.5, more preferably from 0.5 to 5, even more preferably from 1 to 4. Formulating
the compositions according to the present invention in the acidic pH range contributes
to the chemical stability of the additive compositions according to the present invention.
The pH of the composition is preferably below the pKa of acid corresponding to the
imido-type peroxy acid used. It is believed that the acidic pH controls/limits the
formation of highly reactive species which are instable in acidic medium upon storage,
and thus contributes to the stability of the compositions for prolonged periods of
storage.
[0027] The pH of the compositions is governed by the concentration and type of source of
protons as discussed herein below.
[0028] The bleaching performance of the liquid bleach additive compositions herein may be
evaluated by the following test methods on various types of bleachable stains :
A suitable test method for evaluating the bleaching performance on a soiled fabric
under additive-conditions (also referred herein as "through-the-wash" conditions)
is the following: A liquid bleach additive composition is used in the wash-cycle of
a conventional washing machine. The liquid bleach additive composition is added together
with a conventional particulate laundry detergent (such as DASH® powder, TIDE®, ARIEL
tablets®, ARIEL® powder). The liquid bleach additive composition is dosed at 50 to
100 ml per wash load and the conventional laundry detergent is dosed at 110 grams
per wash load for granules and 2 tabs per wash load for tablets (recommended dosages).
In the washing machine the soiled fabrics are washed according to the standard procedure
of the washing machine at a temperature of from 30° to 70°C for 10 to 100 minutes
and then rinsed. Reference composition(s) in the comparative test undergo the same
treatment. Soiled fabrics/swatches with for example tea, coffee and the like may be
commercially available from E.M.C. Co. Inc..
[0029] A visual grading may be used to assign difference in panel units (psu) in a range
from 0 to 4, wherein 0 means no noticeable difference in bleaching performance between
a liquid bleach additive composition according to the present invention and a reference
composition and 4 means a noticeable difference in bleaching performance between a
liquid bleach additive composition according to the present invention and a reference
composition.
Imido-type peroxy acids
[0030] The bleaching composition of the present invention comprises an imido-type peroxy
acid. Said imido-type peroxy acid is preferably a solid, substantially water insoluble
pre-formed imido-type peroxy acid. In a preferred embodiment of the present invention
the imido-type peroxy acid has the general formula:
X-R-C(O)OOH
wherein R is a linear or branched, substituted or unsubstituted hydrocarbon chain
having at least 1 carbon atom and X is a substituted imide, preferably a substituted
imide wherein the imidic nitrogen forms a bond with R.
[0031] By a "substituted imide" it is meant herein an imide having a substitution on the
nitrogen.
[0032] Preferably the imido-type peroxy acid is according to the general formula :

wherein R1 and R2 are independently linear or branched, substituted or unsubstituted
hydrocarbon chains having at least 1 carbon atom, preferably aliphatic or aromatic
hydrocarbon chains and may form a ring.
[0033] More particularly the R group preferably comprises from 2 to 24 carbon atoms. Alternatively,
the R group may be a branched alkyl chain comprising one or more side chains which
comprise substituent groups selected from the group consisting of aryl, halogen, ester,
ether, amine, amide, substituted phthalic amino, imide, hydroxide, sulphide, sulphate,
sulphonate, carboxylic, heterocyclic, nitrate, aldehyde, ketone or mixtures thereof.
[0034] In a preferred peracid the X group, according to the above general formula, is a
phthalimido group. Thus, particularly preferred imido-type peroxy acids herein are
those having general formula:

where R is C1-20 alkyl group and where A, B, C and D are independently either hydrogen
or substituent groups individually selected from the group consisting of alkyl, hydroxyl,
nitro, halogen, amine, ammonium, cyanide, carboxylic, sulphate, sulphonate, aldehydes
or mixtures thereof.
[0035] In a preferred aspect of the present invention R is an alkyl group having from 3
to 12 carbon atoms, more preferably from 5 to 9 carbon atoms. Preferred substituent
groups A, B, C and D are linear or branched alkyl groups having from 1 to 5 carbon
atoms, but more preferably hydrogen.
[0036] In a preferred embodiment herein, said imido-type peroxy acid is an imido-type peroxy
alkanoic acid, preferably a phthalimido peroxy alkanoic acid, even more preferably
said imido-type peroxy acid is selected from the group consisting of : ε-phthalimido
peroxy hexanoic acid (also known as Phthalimido peroxy caproic acid - PAP); phthalimido
peroxy heptanoic acid; phthalimido peroxy octanoic acid; phthalimido peroxy nonanoic
acid; and Phthalimido peroxy decanoic acid; and mixtures thereof and most preferably
ε-phthalimido peroxy hexanoic acid (PAP).
[0037] Suitable phthalimido peroxy alkanoic acid have the general formula:

wherein R is selected from C1-4 alkyl and n is an integer of from 1 to 5.
[0038] PAP (ε-phthalimido peroxy hexanoic acid) as mentioned above is according to the above
formula wherein R is CH
2 and n is 5.
[0039] PAP is preferably used as a substantially water-insoluble solid or wet-cake and is
available from Ausimont under the trade name Eureco®.
[0040] Said imido-type peroxy acid may be present at a level in the composition of from
0.1% to 10% more preferably 0.1% to 5% and most preferably 1% to 5% by weight of the
total composition. Alternatively the peracid may be present at a much higher level
of for example 10% to 40%, more preferably from 15% to 30%, most preferably from 20%
to 25% by weight of the total composition.
Source of protons
[0041] The compositions herein comprise a source of protons having at least one acidic moiety
donating protons in water at a pH below 7.5, wherein said composition comprises at
least 0.80 mmoles of protons available at pH below 7.5 per gram of composition. The
compositions herein may comprise a mixture of suitable sources of protons.
[0042] By a "source of protons" it is meant herein a species with Lewis/Bronsted acid behavior,
i.e., a species which in water solution is capable of donating a proton or accepting
an electron pair from another species.
[0043] By "mmoles of protons available at pH below 7.5 per gram of composition" it is meant
herein the concentration of protons (in mmoles per gram of composition) available,
this means either free protons or protons that may disassociate, at a pH below 7.5,
which are capable of being delivered to (alkaline / base) species present in the wash
solution and thereby reducing the pH in the wash liquor / solution formed by a conventional
laundry detergent, preferably a conventional particulate laundry detergent.
[0044] The concentration (in mmoles per gram of composition) of available protons in a given
composition is equivalent to the amount in mmoles of 1 M Sodium Hydroxide solution
(1 mol of NaOH in 1 liter of demin. water) needed to bring the pH of 100 grams of
the given composition up to a value of 7.5 and divided by 100.
[0045] For example, for 100 grams of a composition consisting of 5 grams citric acid and
95 grams of water (citric acid has mol. wt. of 192.12 and three acidic protons donated
at a pH below 7.5), 79 mmoles of 1 M Sodium Hydroxide solution are required to bring
the pH up to a value of 7.5. This means that said composition comprise a source of
protons donating protons in water at a pH below 7.5 and wherein said source of protons
is present at a concentration of 0.79 mmoles of protons available at pH below 7.5
per gram of composition.
[0046] Alternatively, for 100 grams of a composition consisting of 5 grams succinic acid
and 95 grams of water (succinic acid has mol. wt. of 118.09 and two acidic protons
donated at a pH below 7.5), 85 mmoles of 1 M Sodium Hydroxide solution are required
to bring the pH up to a value of 7.5. This means that said composition comprise a
source of protons donating protons in water at a pH below 7.5 and wherein said source
of protons is present at a concentration of 0.85 mmoles of protons available at pH
below 7.5 per gram of composition.
[0047] Furthermore, for 100 grams of a composition consisting of 4 grams succinic acid,
4 grams of citric acid and 92 grams of water, 130 mmoles of 1 M Sodium Hydroxide solution
are required to bring the pH up to a value of 7.5. This means that said composition
comprise a source of protons donating protons in water at a pH below 7.5 and wherein
said source of protons is present at a concentration of 1.30 mmoles of protons available
at pH below 7.5 per gram of composition.
[0048] The source of protons herein preferably is present at a concentration of at least
0.80, preferably at least 0.90, more preferably 1.0, even more preferably 1.1, yet
more preferably 1.8, still more preferably 2.0 and most preferably 2.5 mmoles of protons
available at pH below 7.5 per gram of composition.
[0049] In a preferred embodiment herein, the source of protons herein may be present at
a concentration of up to 5, preferably up to 4.5, more preferably 4, even more preferably
3.5, yet more preferably 3.0, still more preferably 2.7 mmoles of protons available
at pH below 7.5 per gram of composition.
[0050] Suitable sources of protons herein may be organic or inorganic. Suitable organic
sources of protons herein are selected from the group consisting of : succinic acid,
malonic acid, citric acid, glutaric acid, adipic acid, pimelic acid, suberic acid,
azelaic acid, phtalic acid, isophthalic acid, terephthalic acid, hemimellitic acid,
trimellitic acid, trimesic acid, mellophanic acid, prehnitic acid, pyromellitic acid,
benzenepentacarboxylic acid, and mellitic acid and mitures thereof. Suitable inorganic
sources of protons herein are selected from the group consisting of : hydrogen-sulfuric
acid, and dihydrogen-phosphoric acid, and mixtures thereof. Preferably said source
of protons herein is selected from the group consisting of citric acid, succinic acid,
malonic acid, glutaric acid, and adipic acid and mixtures thereof. More preferably
said source of protons herein is selected from the group consisting of citric acid,
succinic acid and malonic acid, and mixtures thereof. Most preferably said source
of protons herein is citric acid.
[0051] Not suitable as sources of protons herein are for example sodium hydrogen carbonate,
ammonium sulfate, mono ethanol-ammonium sulfate, percarboxylic acids (such as imido-type
peroxy acids, like PAP), peracetic acid and diperpimelic acid. Indeed, without being
limited by theory, the above listed un-suitable sources of protons fail to donate
(or at least sufficiently donate) protons at a pH below 7.5.
[0052] In a highly preferred embodiment herein, said source of protons does not include
the imido-type peroxy acid present in the compositions according to the present invention.
[0053] In a preferred embodiment herein, the composition herein comprises citric acid at
concentration of at least 0.051 grams per gram of composition (resulting in a concentration
of at least 0.80 mmoles of protons available at pH below 7.5 per gram of composition),
preferably at least 0.083 grams per gram of composition (resulting in a concentration
of at least 1.3 mmoles of protons available at pH below 7.5 per gram of composition)
and more preferably at least 0.138 grams per gram of composition (resulting in a concentration
of at least 2.2 mmoles of protons available at pH below 7.5 per gram of composition).
[0054] In another preferred embodiment herein, the composition herein comprises succinic
acid at concentration of at least 0.047 grams per gram of composition (resulting in
a concentration of at least 0.80 mmoles of protons available at pH below 7.5 per gram
of composition), preferably at least 0.076 grams per gram of composition (resulting
in a concentration of at least 1.3 mmoles of protons available at pH below 7.5 per
gram of composition), and more preferably at least 0.127 grams per gram of composition
(resulting in a concentration of at least 2.2 mmoles of protons available at pH below
7.5 per gram of composition).
[0055] In another preferred embodiment herein, the composition herein comprises malonic
acid at concentration of at least 0.0416 grams per gram of composition (resulting
in a concentration of at least 0.80 mmoles of protons available at pH below 7.5 per
gram of composition), preferably at least 0.0675 grams per gram of composition (resulting
in a concentration of at least 1.3 mmoles of protons available at pH below 7.5 per
gram of composition), and more preferably at least 0.112 grams per gram of composition
(resulting in a concentration of at least 2.2 mmoles of protons available at pH below
7.5 per gram of composition).
[0056] In another preferred embodiment herein, the composition herein comprises glutaric
acid at concentration of at least 0.0528 grams per gram of composition (resulting
in a concentration of at least 0.80 mmoles of protons available at pH below 7.5 per
gram of composition), preferably at least 0.0859 grams per gram of composition (resulting
in a concentration of at least 1.3 mmoles of protons available at pH below 7.5 per
gram of composition), and more preferably at least 0.143 grams per gram of composition
(resulting in a concentration of at least 2.2 mmoles of protons available at pH below
7.5 per gram of composition).
[0057] In another preferred embodiment herein, the composition herein comprises adipic acid
at concentration of at least 0.0585 grams per gram of composition (resulting in a
concentration of at least 0.80 mmoles of protons available at pH below 7.5 per gram
of composition), preferably at least 0.0950 grams per gram of composition (resulting
in a concentration of at least 1.3 mmoles of protons available at pH below 7.5 per
gram of composition), and more preferably at least 0.158 grams per gram of composition
(resulting in a concentration of at least 2.2 mmoles of protons available at pH below
7.5 per gram of composition).
[0058] In view of the above, the present invention also encompasses a liquid bleach additive
composition having a viscosity of up to 5000 cps and/or comprising at least 50% by
weight of the total composition of water, an imido-type peroxy acid and a source of
protons, wherein said source of protons is selected from the group consisting of :
citric acid present at a level of at least 5.1%; succinic acid present at a level
of at least 4.7%; malonic acid present at a level of at least 4.2%; glutaric acid
present at a level of at least 5.3%; and adipic acid present at a level of at least
5.9%; and mixtures thereof.
[0059] The above also applies to the kit according to the present invention as described
herein.
[0060] The Applicant has found that by reducing the pH in the wash liquor formed by an conventional
laundry detergent, preferably a conventional particulate laundry detergent (including
powders, granules, pearls and tablets) and an imido-type peroxy acid-based, preferably
PAP-based, bleach additive, the through-the-wash bleaching performance of the bleach
additive can be significantly increased. Indeed, it has surprisingly been found that
at a pH above 9, the imido-type peroxy acid molecule, preferably the PAP molecule,
is irreversibly hydrolyzed to a hydrophilic molecule, which fails to be able to penetrate
the hydrophobic fibres of fabrics and therefore also failing to be able to penetrate
the bleachable stains present thereon. This leads to a limited bleaching performance
on stained fabrics, whilst maintaining a good bleaching performance of the wash liquor,
which is an aqueous solution and thus hydrophilic.
[0061] Indeed, the bleaching activity of imido-type peroxy acids is most optimal in a pH
range of from 9.0 to 8.0 For example, the PAP bleaching activity is most optimal at
a pH of 8.4. However, conventional laundry detergents and in particular conventional
granular laundry detergent are heavily buffered compositions providing a wash liquor
having a pH in the range of 9.8-10. Indeed, as shown in Figure 1 herein, a significant
buffering can be observed for conventional granular laundry detergents.
[0062] As shown in Figure 1, in order to reduce the pH of the wash liquor/solution formed
by conventional particulate laundry detergent to below 9, preferably to below 8.8,
high amounts of protons are needed. Indeed, at least 80 mmoles of protons are needed
to bring the pH of the wash solution to a pH below 9.5 and 130 mmoles of protons are
needed to bring the pH of the wash solution to a pH below 8.8.
[0063] The protons have to be added in conjunction with the imido-type peroxy acid-containing
liquid laundry bleach additive as described herein. Indeed, the bleach additive herein
needs to contain high amounts of free acid (i.e., available protons) also referred
to as reserve acidity. Such reserve acidity is provided by the source of protons herein.
[0064] For example, at a dosage of 162 grams of liquid bleach additive composition according
to the present invention per wash-load 130 mmoles of available protons at pH below
7.5 (162 grams times 0.80 mmoles of protons available at pH below 7.5 per gram of
composition) are available to off-set the buffering of the wash solution provided
by the particulate laundry detergent.
[0065] It has been found that by adding a sufficient amount of reserve acidity into an imido-type
peroxy acid-based bleach additive of the present invention, the bleaching performance
of the additive in a through-the-wash bleach operation is significantly increased
in comparison to bleach additives containing no or too little reserve acidity used
in a similar operation.
Optional ingredients
[0066] The compositions herein may further comprise a variety of other optional ingredients
such as polymeric systems, surfactants, chelating agents, radical scavengers, antioxidants,
stabilisers, builders, soil suspending polymer, polymeric soil release agents, dye
transfer inhibitor, solvents, suds controlling agents, suds booster, brighteners,
perfumes, pigments, dyes and the like.
Polymeric system
[0067] The composition of the present invention may comprise a gum-type polymer preferably
selected from the group consisting of polysaccharide hydrocolloids, xanthan gum, guar
gum, succinoglucan gum, cellulose, derivatives of any of the above and mixtures thereof.
In a preferred aspect of the present invention the gum-type polymer is a succinoglucan
gum or a derivative thereof.
[0068] The gum-type polymer is preferably present at a level of from 0.01% to 10%, more
preferably from 0.05% to 3%, even more preferably from 0.1% to 1.0%.
Surfactants
[0069] The compositions of the present invention may comprise a surfactant or a mixture
thereof including nonionic surfactants, anionic surfactants, cationic surfactants,
zwitterionic surfactants and/or amphoteric surfactants.
[0070] Typically, the compositions according to the present invention may comprise up to
10% by weight of the total composition of a surfactant or a mixture thereof, preferably
up to 5 % and more preferably up to 2%.
Hydrotropes
[0071] The compositions of the present invention may comprise a hydrotrope or a mixture
thereof. Hydrotropes are a special class of compounds that are efficient solubilisers,
because they can self-associate in aqueous medium influencing the formation of micelles
and microemulsions.
[0072] Suitable hydrotropes for use herein may include alkylbenzene sulphonates based on
toluene, xylene and cumene, polyhydroxy benzene, sodium salts of lower alkanols and
derivatives of aromatic acids are generally considered to be effective hydrotropes.
[0073] Typically, the compositions according to the present invention may comprise up to
5% by weight of the total composition of a hydrotrope or a mixture thereof, preferably
up to 1 % and more preferably up to 1%.
Chelating agents
[0074] The compositions of the present invention may comprise a chelating agent as a preferred
optional ingredient. Suitable chelating agents may be any of those known to those
skilled in the art such as the ones selected from the group comprising phosphonate
chelating agents, amino carboxylate chelating agents, other carboxylate chelating
agents, polyfunctionally-substituted aromatic chelating agents, ethylenediamine N,N'-
disuccinic acids, or mixtures thereof.
[0075] The presence of chelating agents contribute to further enhance the chemical stability
of the compositions. A chelating agent may be also desired in the compositions of
the present invention as it allows to increase the ionic strength of the compositions
herein and thus their stain removal and bleaching performance on various surfaces.
[0076] Suitable phosphonate chelating agents for use herein may include alkali metal ethane
1-hydroxy diphosphonates (HEDP), alkylene poly (alkylene phosphonate), as well as
amino phosphonate compounds, including amino aminotri(methylene phosphonic acid) (ATMP),
nitrilo trimethylene phosphonates (NTP), ethylene diamine tetra methylene phosphonates,
and diethylene triamine penta methylene phosphonates (DTPMP). The phosphonate compounds
may be present either in their acid form or as salts of different cations on some
or all of their acid functionalities. Preferred phosphonate chelating agents to be
used herein are diethylene triamine penta methylene phosphonate (DTPMP) and ethane
1-hydroxy diphosphonate (HEDP). Such phosphonate chelating agents are commercially
available from Monsanto under the trade name DEQUEST®·
[0077] Polyfunctionally-substituted aromatic chelating agents may also be useful in the
compositions herein. See U.S. patent 3,812,044, issued May 21, 1974, to Connor et
al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such
as 1,2-dihydroxy -3,5-disulfobenzene.
[0078] A preferred biodegradable chelating agent for use herein is ethylene diamine N,N'-disuccinic
acid, or alkali metal, or alkaline earth, ammonium or substitutes ammonium salts thereof
or mixtures thereof. Ethylenediamine N,N'- disuccinic acids, especially the (S,S)
isomer have been extensively described in US patent 4, 704, 233, November 3, 1987,
to Hartman and Perkins. Ethylenediamine N,N'- disuccinic acids is, for instance, commercially
available under the tradename ssEDDS® from Palmer Research Laboratories.
[0079] Suitable amino carboxylates to be used herein include ethylene diamine tetra acetates,
diethylene triamine pentaacetates, diethylene triamine pentaacetate (DTPA),N-hydroxyethylethylenediamine
triacetates, nitrilotri-acetates, ethylenediamine tetrapropionates, triethylenetetraaminehexa-acetates,
ethanol-diglycines, propylene diamine tetracetic acid (PDTA) and methyl glycine di-acetic
acid (MGDA), both in their acid form, or in their alkali metal, ammonium, and substituted
ammonium salt forms. Particularly suitable amino carboxylates to be used herein are
diethylene triamine penta acetic acid, propylene diamine tetracetic acid (PDTA) which
is, for instance, commercially available from BASF under the trade name Trilon FS®
and methyl glycine di-acetic acid (MGDA).
[0080] Further carboxylate chelating agents to be used herein include salicylic acid, aspartic
acid, glutamic acid, glycine, malonic acid or mixtures thereof.
[0081] Another chelating agent for use herein is of the formula:

wherein R
1, R
2, R
3, and R
4 are independently selected from the group consisting of -H, alkyl, alkoxy, aryl,
aryloxy, -Cl, -Br, -NO
2, -C(O)R', and -SO
2R"; wherein R' is selected from the group consisting of -H, -OH, alkyl, alkoxy, aryl,
and aryloxy; R" is selected from the group consisting of alkyl, alkoxy, aryl, and
aryloxy; and R
5, R
6, R
7, and R
8 are independently selected from the group consisting of -H and alkyl.
[0082] Particularly preferred chelating agents to be used herein are amino aminotri(methylene
phosphonic acid), di-ethylene-triamino-pentaacetic acid, diethylene triamine penta
methylene phosphonate, 1-hydroxy ethane diphosphonate, ethylenediamine N, N'-disuccinic
acid, and mixtures thereof.
[0083] Typically, the compositions according to the present invention comprise up to 5%
by weight of the total composition of a chelating agent, or mixtures thereof, preferably
from 0.01% to 1.5% by weight and more preferably from 0.01% to 0.5%.
Radical scavengers
[0084] The compositions of the present invention may comprise a radical scavenger or a mixture
thereof.
[0085] Suitable radical scavengers for use herein include the well-known substituted mono
and dihydroxy benzenes and their analogs, alkyl and aryl carboxylates and mixtures
thereof. Preferred such radical scavengers for use herein include di-tert-butyl hydroxy
toluene (BHT), hydroquinone, di-tert-butyl hydroquinone, mono-tert-butyl hydroquinone,
tert-butyl-hydroxy anysole, benzoic acid, toluic acid, catechol, t-butyl catechol,
benzylamine, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl) butane, n-propyl-gallate
or mixtures thereof and highly preferred is di-tert-butyl hydroxy toluene. Such radical
scavengers like N-propyl-gallate may be commercially available from Nipa Laboratories
under the trade name Nipanox S1 ®.
[0086] Radical scavengers when used, are typically present herein in amounts up to 10% by
weight of the total composition and preferably up to 0.5% by weight.
[0087] The presence of radical scavengers may contribute to the chemical stability of the
bleaching compositions of the present invention as well as to the safety profile of
the compositions of the present invention.
Stabilisers
[0088] The compositions of the present invention may further a stabilizer. Examples of inorganic
stabilizers include sodium stannate and various alkali metal phosphates such as the
well-known sodium tripolyphosphates, sodium pyrophosphate and sodium orthophosphate.
Soil suspending polymer
[0089] The compositions according to the present invention may further comprise a soil suspending
polyamine polymer or mixtures thereof, as optional ingredient. Any soil suspending
polyamine polymer known to those skilled in the art may be used herein. Particularly
suitable polyamine polymers for use herein are polyalkoxylated polyamines.
[0090] Typically, the compositions comprise up to 10% by weight of the total composition
of such a soil suspending polyamine polymer or mixtures thereof, preferably from 0.1%
to 5% and more preferably from 0.3% to 2%.
[0091] The compositions herein may also comprise other polymeric soil release agents known
to those skilled in the art. Such polymeric soil release agents are characterised
by having both hydrophilic segments, to hydrophilize the surface of hydrophobic fibres,
such as polyester and nylon, and hydrophobic segments, to deposit upon hydrophobic
fibres and remain adhered thereto through completion of washing and rinsing cycles
and, thus, serve as an anchor for the hydrophilic segments. This can enable stains
occurring subsequent to treatment with the soil release agent to be more easily cleaned
in later washing procedures.
[0092] If utilized, soil release agents will generally comprise from 0.01% to 10.0%, by
weight, of the detergent compositions herein, typically from 0.1% to 5%, preferably
from 0.2% to 3.0%.
Brightener
[0093] Any optical brighteners, fluorescent whitening agents or other brightening or whitening
agents known in the art can be incorporated in the instant compositions when they
are designed for fabric treatment or laundering, at levels typically from about 0.05%
to about 1.2%, by weight, of the detergent compositions herein.
Minor Ingredients
[0094] The composition described herein may also comprise minor ingredients such as pigment
or dyes, suds controlling agents, dye transfer inhibitors, suds boosters and perfumes.
Processes of treating fabrics
[0095] The present invention encompasses a process of treating fabrics which comprises the
steps of forming an aqueous bath comprising water, a conventional laundry detergent,
preferably a granular laundry detergent, and a liquid bleach additive composition
according to the present invention, and subsequently contacting said fabrics with
said aqueous bath.
[0096] In a highly preferred embodiment herein, the liquid bleach additive compositions
according to the present invention are dosed herein to provide at least 80 mmoles,
preferably 100 mmoles, more preferably 130 mmoles, still more preferably 180 mmoles,
most preferably 210 mmoles of protons available at pH below 7.5 per wash-load. Indeed,
sufficient amount of said liquid bleach additive composition is added to provide the
above amounts of protons available at pH below 7.5.
[0097] Typically, the liquid bleach additive compositions according to the present invention
are dosed at minimum 50 grams per wash-load, preferably of from 55 grams to 170 grams,
more preferably 60 grams to 110 grams. The dosage of the liquid bleach additive composition
herein depends on the level of protons available at a pH below 7.5 per gram of composition.
Indeed, compositions having levels of protons available at a pH below 7.5 per gram
of composition at the minimum required level herein (0.8 mmoles per gram of composition)
require a higher dosage (162.5 grams to, e.g., donate 130 mmoles of protons available
at pH below 7.5 per wash-load). Compositions having levels of protons available at
a pH below 7.5 per gram of composition above the minimum required level herein (e.g.,
1.3 mmoles per gram of composition) require a lower dosage (100 grams to, e.g., donate
130 mmoles of protons available at pH below 7.5 per wash-load).
[0098] Moreover, the present invention encompasses a process of treating fabrics which comprises
the steps of forming an aqueous bath comprising water, a conventional laundry detergent,
preferably a granular laundry detergent, and a liquid bleach additive composition
formed by the at least two compositions of the kit according to the present invention,
and subsequently contacting said fabrics with said aqueous bath.
[0099] In the specific embodiment herein, wherein the liquid bleach additive composition
is formed by the at least two compositions of the kit according to the present invention,
the mixing of the at least two compositions of said kit may occur prior to forming
said aqueous bath (i.e., before adding it to the washing machine) and/or at the same
time as forming said aqueous bath (i.e., in the washing machine).
[0100] In a highly preferred embodiment herein, the combination of compositions in the kit
according to the present invention are dosed herein to provide at least 80 mmoles,
preferably 100 mmoles, more preferably 130 mmoles, still more preferably 180 mmoles,
most preferably 210 mmoles of protons available at pH below 7.5 per wash-load. Typically,
the combination of compositions in the kit according to the present invention are
dosed at minimum 50 grams per wash-load, preferably of from 55 grams to 170 grams,
more preferably 60 grams to 110 grams. As outlined above, the dosage of the liquid
bleach additive composition herein depends on the level of protons available at a
pH below 7.5 per gram of composition.
[0101] The processes of treating, preferably bleaching, fabrics according to the present
invention delivers effective whiteness performance as well as effective stain removal
performance.
[0102] The process of treating fabrics herein comprises the steps of forming an aqueous
bath comprising water, a conventional laundry detergent and a liquid bleach additive
composition, as described herein, subsequently contacting said fabrics with said aqueous
bath.
[0103] By "conventional laundry detergent" it is meant herein, a laundry detergent composition
currently available on the market. Preferably, said conventional laundry detergent
comprises at least one surfactant. Said laundry detergent compositions may be formulated
as particulates (including powders, pearls, granules, tablets and the like), liquids
(liquids, gels, and the like) as well as detergent forms based on water-soluble or
water-permeable pouches comprising liquids and/or particulates (such as liquid-tabs).
Suitable particulate laundry detergent compositions are for example DASH powder®,
ARIEL tablets®, ARIEL powder® and other products sold under the trade names ARIEL®
or TIDE®.
[0104] In a preferred embodiment herein, the conventional laundry detergent is a conventional
particulate laundry detergent more preferably a conventional powder, pearl, granule
or tablet laundry detergent.
[0105] In a preferred embodiment according to the present invention, the conventional laundry
detergent as described herein and, the liquid bleach additive composition herein are
dissolved or dispersed, preferably substantially dissolved or dispersed, in the aqueous
bath formed in the process according to the present invention. By "substantially dissolved
or dispersed" it is meant herein, that at least 50%, preferably at least 80%, more
preferably at least 90%, even more preferably at least 95%, still more preferably
at least 98%, and most preferably at least 99%, of said conventional laundry detergent
and/or said liquid bleach additive composition are dissolved or dispersed in the aqueous
bath formed in the process according to the present invention.
[0106] The liquid bleach additive composition and the conventional detergent composition
may be delivered into the washing machine either by charging the dispenser drawer
of the washing machine with one or both of the detergents or by directly charging
the drum of the washing machine with one or both of the detergents. More preferably
the liquid bleach additive composition is directly placed into the drum of the washing
machine, preferably using a dosing device, such as a dosing ball (such as the Vizirette®).
Even more preferably the liquid bleach additive composition and the conventional detergent
composition are both placed into the drum of the washing machine, preferably using
suitable dosing devices such as dosing balls, dosing nets etc. The liquid bleach additive
composition is preferably delivered to the main wash cycle of the washing machine
before, but more preferably at the same time as the conventional detergent composition.
[0107] During the processes according to the present invention the liquid bleach additive
compositions herein is typically used in diluted form. By "in diluted form", it is
meant herein that the liquid bleach additive compositions according to the present
invention may be diluted by the user, preferably with water. The dilution occurs in
a washing machine. Said compositions can be diluted up to 500 times, preferably from
5 to 200 times and more preferably from 10 to 80 times.
Packaging form of the liquid compositions:
[0108] Depending on the end-use envisioned, the compositions herein can be packaged in a
variety of containers including conventional bottles.
[0109] The present invention further encompasses as a separate embodiment, a kit comprising
at least two compositions, wherein a first composition comprises an imido-type peroxy
acid and optionally a source of protons having at least one acidic moiety donating
protons in water at a pH below 7.5, and wherein a second composition comprises a source
of protons having at least one acidic moiety donating protons in water at a pH below
7.5, wherein said compositions when combined comprise at least 0.80 mmoles of protons
available at pH below 7.5 per gram of mixed compositions.
[0110] By "combined" or "mixed" it is meant the combination of the compositions present
in the kit at a ratio according to the use instructions or implied use conditions
intended for the kit. For dual compartment containers this may be a 1:1 mix-ratio.
However, other mix ratios are also envisage herein.
[0111] The concentration (in mmoles per gram of composition) of available protons in a given
mixture of compositions is equivalent to the amount in mmoles of 1 M Sodium Hydroxide
solution (NaOH) needed to bring the pH of 100 grams of the given composition up to
a value of 7.5 and divided by 100, as discussed herein above.
[0112] In case the kit according to the present invention comprises at least one solid composition,
the concentration of available protons is assessed by dissolving 100 grams of combined
composition in 100 g of demin. Water.
[0113] In this embodiment of the present invention the at least two compositions herein
may be packaged in a two compartment container or in two separate containers. Furthermore,
one or more of said at least two compositions may be packaged in a water-soluble container,
such as a water-soluble pouch (preferably made of polyvinyl-alcohol or -acetate pouch).
[0114] The compositions in the kit according to the present invention may independently
be solid or liquid compositions. The compositions and optional ingredients may be
similar to the ones discussed herein above.
[0115] In a highly preferred embodiment, at least one of the compositions present in said
kit is a liquid composition having similar properties as described herein above. Even
more preferably, the kit comprises at least two liquid compositions, more preferably
two compositions, packed in a two compartment container.
[0116] The invention is further illustrated by the following examples.
Examples
[0117] The following examples will further illustrate the present invention. The compositions
are made by combining the listed ingredients in the listed proportions (weight % unless
otherwise specified). Furthermore, the compositions comprise water and minors up to
100%. The following Examples are meant to exemplify compositions according to the
present invention but are not necessarily used to limit or otherwise define the scope
of the present invention.

Witkonate NAS 8® is an alkyl sulphonate available from Witco AS.
BHT is di-tert butyl hydroxy toluene.
HEDP is ethane 1-hydroxy diphosphonate commercially available from Monsanto under
the DEQUEST® series.
PAP is phthalimido peroxy hexanoic acid available from Ausimont under the tradename
Eureco®.
NaXS is sodium xylene sulfonate, available from Rhodia under the trade name of Eltesol
SX 33®.
1. A liquid bleach additive composition having a viscosity of up to 5000 cps and/or comprising
at least 50% by weight of the total composition of water, and additionally comprising
an imido-type peroxy acid and a source of protons having at least one acidic moiety
donating protons in water at a pH below 7.5, wherein said composition comprises at
least 0.80 mmoles of protons available at pH below 7.5 per gram of composition.
2. A liquid bleach additive composition according to claim 1, wherein said imido-type
peroxy acid is a solid, substantially water insoluble pre-formed imido-type peroxy
acid.
3. A liquid bleach additive composition according to any of the preceding claims, wherein
said imido-type peroxy acid has the general formula:

wherein R is C1-20 alkyl group and where A, B, C and D are independently either hydrogen
or substituent groups individually selected from the group consisting of alkyl, hydroxyl,
nitro, halogen, amine, ammonium, cyanide, carboxylic, sulphate, sulphonate, aldehydes
or mixtures thereof.
4. A liquid bleach additive composition according to any preceding claim, wherein said
imido-type peroxy acid has general formula:

wherein R is C
1-4 alkyl and n is an integer of from 1 to 5.
5. A liquid bleach additive composition according to any preceding claim, wherein said
imido-type peroxy acid is an imido-type peroxy alkanoic acid, preferably a phthalimido
peroxy alkanoic acid, even more preferably said imido-type peroxy acid is selected
from the group consisting of : ε-phthalimido peroxy hexanoic acid; phthalimido peroxy
heptanoic acid; phthalimido peroxy octanoic acid; phthalimido peroxy nonanoic acid;
and Phthalimido peroxy decanoic acid; and mixtures thereof and most preferably ε-phthalimido
peroxy hexanoic acid.
6. A liquid bleach additive composition according to any preceding claim, wherein said
composition comprises of from 0.1% to 10%, more preferably from 0.1% to 5% and most
preferably from 1% to 5% by weight of the total composition of said imido-type peroxy
acid.
7. A liquid bleach additive composition according to any of claims 1 to 5, wherein said
composition comprises of from 10% to 40%, more preferably from 15% to 30%, most preferably
from 20% to 25% by weight of the total composition of said imido-type peroxy acid.
8. A liquid bleach additive composition according to any preceding claim, wherein said
source of protons is present at a concentration of at least 0.90 mmoles, preferably
1.0 mmoles, more preferably 1.1 mmoles, yet more preferably 1.8 mmoles, still more
preferably 2.0 mmoles and most preferably 2.5 mmoles of protons available at pH below
7.5 per gram of composition.
9. A liquid bleach additive composition according to any preceding claim, wherein said
source of protons is present at a concentration of up to 5 mmoles, preferably up to
4.5 mmoles, more preferably 4 mmoles, even more preferably 3.5 mmoles, yet more preferably
3.0 mmoles, still more preferably 2.7 mmoles of protons available at pH below 7.5
per gram of composition.
10. A liquid bleach additive composition according to any preceding claim, wherein said
source of protons is an organic source of protons selected from the group consisting
of : succinic acid, malonic acid, citric acid, glutaric acid, adipic acid, pimelic
acid, suberic acid, azelaic acid, phtalic acid, isophthalic acid, terephthalic acid,
hemimellitic acid, trimellitic acid, trimesic acid, mellophanic acid, prehnitic acid,
pyromellitic acid, benzenepentacarboxylic acid, and mellitic acid and mixtures thereof.
11. A liquid bleach additive composition according to any of claims 1 to 9, wherein said
source of protons is an inorganic source of protons selected from the group consisting
of : hydrogen-sulfuric acid, and dihydrogen-phosphoric acid, and mixtures thereof.
12. A liquid bleach additive composition according to any of claims 1 to 9, wherein said
source of protons is selected from the group consisting of citric acid, succinic acid,
malonic acid, glutaric acid, and adipic acid and mixtures thereof.
13. A process of treating fabrics which comprises the steps of forming an aqueous bath
comprising water, a conventional laundry detergent, preferably a granular laundry
detergent, and a liquid bleach additive composition according to any of the preceding
claims, and subsequently contacting said fabrics with said aqueous bath.
14. A process of treating fabrics according to claim 13, wherein sufficient amount of
said liquid bleach additive composition is added to provide at least 80 mmoles, preferably
100 mmoles, more preferably 130 mmoles, still more preferably 180 mmoles, most preferably
210 mmoles of protons available at pH below 7.5.
15. A liquid bleach additive composition having a viscosity of up to 5000 cps and/or comprising
at least 50% by weight of the total composition of water, and additionally comprising
an imido-type peroxy acid and a source of protons, wherein said source of protons
is selected from the group consisting of : citric acid present at a level of at least
5.1%; succinic acid present at a level of at least 4.7%; malonic acid present at a
level of at least 4.2%; glutaric acid present at a level of at least 5.3%; and adipic
acid present at a level of at least 5.9%; and mixtures thereof.
16. A kit comprising at least two compositions, wherein a first composition comprises
an imido-type peroxy acid and optionally a source of protons having at least one acidic
moiety donating protons in water at a pH below 7.5, and wherein a second composition
comprises a source of protons having at least one acidic moiety donating protons in
water at a pH below 7.5, wherein said compositions when combined comprise at least
0.80 mmoles of protons available at pH below 7.5 per gram of mixed compositions.
17. A process of treating fabrics which comprises the steps of forming an aqueous bath
comprising water, a conventional laundry detergent, preferably a granular laundry
detergent, and a liquid bleach additive composition formed by the at least two compositions
of the kit according to claim 16, and subsequently contacting said fabrics with said
aqueous bath.
18. The use of a source of protons having at least one acidic moiety donating protons
in water at a pH below 7.5, in a liquid bleach additive composition comprising an
imido-type peroxy acids, wherein said composition comprises at least 0.80 mmoles of
protons available at pH below 7.5 per gram of composition to provide effective bleaching
performance on stained fabrics, when used in conjunction with a conventional particulate
laundry detergent.