Technical Field
[0001] The present invention relates to the bleaching of fabrics with liquid aqueous persulfate-containing
bleaching compositions having a pH below 7.
Background of the invention
[0002] Liquid aqueous bleaching compositions suitable for laundry applications are well
known in the art. It is also known that liquid bleaching compositions relying on hypochlorite
as the bleaching agent can be preferred over oxygen bleaches like hydrogen peroxide,
mainly for performance reasons, especially at lower temperatures.
[0003] However, there are some limitations to the convenience of hypochlorite beaches. In
particular, it is well known from consumers that hypochlorite bleaching may cause
yellowing and/or damage of the fabrics which are being bleached. This holds particularly
true for synthetic fabrics and indeed there is a standing prejudice against using
hypochlorite bleaches on synthetic fibers, as evidenced by warnings on labels of commercially
available hypochlorite bleaches. Also, a variety of fabrics made of or containing
synthetic fibers are labeled by their manufacturers as non-bleachable. Also another
drawback associated to liquid aqueous hypochlorite-based bleaching compositions is
that undesirable typical chlorine odor may be perceived by the consumer during and
after use, e.g., on the hands of the user or fabrics that have been bleached with
such compositions.
[0004] Colour and fabric damage can be minimised by using milder oxygen bleaches such as
hydrogen peroxide. However, the bleaching characteristics of such peroxygen bleaches
are much less desirable than those of the harsh halogen bleaching agents. Therefore
liquid aqueous peroxygen bleach-containing compositions have been developed containing
activators, i.e., compounds which enhance peroxygen bleaching performance. Such activated
hydrogen peroxide-containing compositions are, for example, exemplified in EP-598
170. However, consumers are still not fully satisfactory when bleaching fabrics with
such compositions and are looking for improved overall stain removal performance on
a variety of stains including greasy stains and enzymatic stains as well as further
improved bleaching performance when bleaching fabrics.
[0005] It is therefore an object of the present invention to address the issues mentioned
above, namely those of providing improved overall stain removal performance on a wide
range of stains as well as improved bleaching performance when bleaching fabrics.
More particularly, it is an object of the present invention to provide effective overall
stain removal and effective bleaching performance while being safe to the fabrics
bleached and to colours.
[0006] We have found that these issues are efficiently addressed when soiled (coloured)
fabrics are bleached with an acidic liquid aqueous composition (pH<7) containing a
persulfate salt. Indeed, it has been found that when the process of bleaching fabrics
according to the present invention includes the steps of diluting in an aqueous bath
an acidic liquid aqueous composition comprising a persulfate salt, and of contacting
said fabrics with said aqueous bath comprising said composition and subsequently rinsing
said fabrics with water, improved overall stain removal performance and improved bleaching
performance is delivered, as compared to the same bleaching process where the same
acidic liquid aqueous composition but based, for example, on activated (e.g. acetyl
triethyl citrate) hydrogen peroxide as the bleaching agents at the same total level
of bleaching agents instead of persulfate salt, is used.
[0007] Advantageously, the bleaching processes herein starting from the liquid aqueous persulfate-containing
compositions as described herein, provide effective bleaching performance and effective
stain removal performance even under short soaking time conditions, typically below
30 minutes, more preferably below 10 minutes and most preferably below 5 minutes.
Furthermore, the bleaching processes herein starting from the liquid persulfate-containing
compositions as described herein, provide effective bleaching performance and effective
stain removal performance even under soaking conditions where the aqueous bath is
made of cold water, typically down to 4°C (preferably below 40°C and most preferably
from 10°C to 30°C). Thus, the present invention provides a process of bleaching fabrics
that best needs the today consumers needs, i.e. a process of bleaching fabrics that
provides effective bleaching and stain removal performance in reduced time periods
and/or by using cold water. Actually, an advantage of the process of bleaching a fabric
herein is that the acidic liquid aqueous persulphate-containing composition herein
is effective since the first instants of its dilution in the aqueous bath. This is
because it quickly dissolves in the aqueous bath.
[0008] Advantageously, it has been found that these improved bleaching performance and improved
overall stain removal performance are provided with the processes according to the
present invention even for acidic liquid aqueous persulfate-containing compositions
having undergone long storage time before their use according to the processes herein.
[0009] In a preferred aspect of the process of bleaching fabrics according to the present
invention the acidic liquid aqueous composition used preferably comprises on top of
the persulfate salt, a bleach activator being an aldehyde and/or ketone and/or halide
activator compound, for further improved bleaching performance and improved stain
removal performance.
[0010] Advantageously, the laundry bleaching operations according to the present invention
are safe to the fabrics perse and/or fabrics colours. Indeed, it has been surprisingly
been found that when formulating a persulfate salt and optionally an activator compound
as described herein after, in a liquid aqueous composition having a pH below 7, the
safety (both fabric safety and colour safety) delivered to the fabrics bleached therewith
according to the process of the present invention is improved as compared to formulating
the same ingredients in a granular composition.
[0011] Finally, the process of bleaching fabrics according to the present invention has
the advantage of being odour free on hands if a hand bleaching operation is carried
out and/or on the fabrics so bleached.
Summary of the invention
[0012] The present invention encompasses a process of bleaching a fabric which comprises
the steps of :
- diluting in an aqueous bath a liquid aqueous composition in its neat form, having
a pH below 7 and comprising a persulfate salt,
- contacting said fabric with said aqueous bath comprising said liquid composition,
and subsequently rinsing said fabric with water.
[0013] In its broadest aspect, the present invention encompasses the use of a liquid aqueous
bleaching composition having a pH below 7 and comprising a persulfate salt and optionally
a bleach activator being an aldehyde, ketone and/or halide activator compound for
the bleaching of fabrics, for reducing the loss of tensile strength in said fabrics.
Furthermore, the present invention encompasses the use of a liquid aqueous bleaching
composition having a pH below 7 and comprising a persulfate salt and optionally a
bleach activator being an aldehyde, ketone and/or halide activator compound for the
bleaching of coloured fabrics, for reducing the colour damage to said fabrics.
Detailed Description
The process of bleaching fabrics:
[0014] The present invention encompasses a process of bleaching fabrics as described herein
after.
[0015] By "fabrics", it is to he understood any types of fabrics including for example clothes,
curtains, drapes, bed linens, bath linens, table cloths, sleeping bags, tents, upholstered
furniture and the like.
[0016] The process of bleaching fabrics herein is suitable for both natural fabrics and
synthetic fabrics. By "natural" fabrics, it is meant fabrics made of cotton, viscose,
linene, silk and/or wood. By "synthetic" fabrics, it is meant those made of synthetic
fibers like polymeric fibers (polyamide, polyester, lycra® and elasthan®), and those
made of both natural and synthetic fibers.
[0017] The process of bleaching fabrics according to the present invention comprises the
steps of:
- diluting in an aqueous bath a liquid aqueous composition in its neat form, having
a pH below 7 and comprising a persulfate salt,
- contacting said fabrics with said aqueous bath comprising said liquid composition,
- and subsequently rinsing said fabrics with water.
[0018] By "diluting in an aqueous bath a liquid composition in its neat form", it is meant
herein that the liquid compositions per se as described herein, are diluted typically
with water to form an aqueous bath to which the fabrics to be bleached will be contacted
before being rinsed.
[0019] In the process of bleaching fabrics of the present invention, the fabrics are left
into contact with the aqueous bath (in the so-called "soaking step") for a period
of time sufficient to bleach the fabrics. This period of time typically ranges from
1 minute to 24 hours, preferably from 3 minutes to 12 hours and more preferably from
4 minutes to 6 hours. Advantageously, the process of bleaching according to the present
invention provides effective bleaching performance and effective stain removal performance
even upon shorter soaking time, typically below 1 hour, preferably below 20 minutes
and more preferably from 4 minutes to 15 minutes.
[0020] The dilution level that the liquid aqueous composition as described herein, undergoes
in the process of the bleaching fabrics herein is a dilution of the composition into
water of up to 500 times its weight, preferably from 5 to 200 times and more preferably
from 10 to 80 times. Such dilution may occur for instance in hand laundry applications
as well as by the other means such as in washing machine.
[0021] Although, the temperature of the bleaching process does have an influence on the
stain removal performance and/or bleaching performance of the liquid aqueous persulfate-containing
compositions used herein, effective stain removal performance and/or bleaching performance
are provided even at low temperatures typically down to 4°C. More particularly, these
benefits are observed not only at low temperatures but also under short soaking periods,
typically below 20 minutes. It is also understood that by increasing the temperature
the bleaching process can be accelerated, i.e. the time required to bleach a given
soiled fabric is reduced. Typically, the aqueous baths occurring in the bleaching
processes according to the present invention where the persulfate bleaching compositions
as described herein are diluted have a temperature of from 4°C to 60°C, preferably
from 10°C to 50°C and most preferably from 15°C to 30°C.
[0022] Surprisingly, the process of bleaching fabrics according to the present invention
provides improved bleaching performance and improved overall stain removal performance,
as compared to the same process where the bleaching composition used is a liquid aqueous
composition based on activated hydrogen peroxide at the same total level of bleaching
agents. Also these benefits are obtained with the process of bleaching fabrics according
to the present invention with short soaking time in both cold or hot aqueous baths.
[0023] Indeed, effective bleaching performance is provided on a variety of bleachable soils,
from hydrophobic to hydrophilic soils on both hydrophilic and hydrophobic fabrics.
Effective bleaching performance herein also includes effective whiteness.
[0024] Advantageously, the present invention provides not only effective bleaching performance
but also overall effective stain removal performance on various types of stains including
greasy stains (e.g., lipstick, tomato, make-up) and/or enzymatic stains (e.g. blood,
choco pudding).
[0025] If said fabrics are to be washed, i.e., with a conventional laundry detergent composition
comprising at least one surface active agent, said washing may be conducted together
with the bleaching of said fabrics by contacting said fabrics at the same time with
the liquid aqueous bleaching composition as described herein and a laundry detergent
composition, or said washing may be conducted before or after that said fabrics have
been bleached. Accordingly, the process according to the present invention allows
to bleach fabrics and optionally to wash fabrics with a detergent composition comprising
at least one surface active agent before the step of contacting said fabrics with
said aqueous bath comprising the liquid aqueous composition and/or in the step where
said fabrics are contacted with said aqueous bath and/or after the step where said
fabrics are contacted with said aqueous bath and before the rinsing step and/or after
the rinsing step.
[0026] In a preferred embodiment herein the fabrics are preferably washed in a separate
step from the bleaching step to get optimum bleaching and stain removal performance.
Indeed, conducting the bleaching and washing with a detergent composition in the same
step may cause chemical interaction between the persulfate salt coming from the liquid
aqueous composition and the conventional detergent ingredients typically present in
a conventional detergent composition, i.e. enzymes, surfactants and the like and thus
may reduce the bleaching performance and/or overall stain removal performance.
[0027] In a highly preferred embodiment of the present invention, it is preferred to perform
the bleaching process herein after said fabrics have been first washed with a conventional
laundry detergent composition. Indeed, it has been observed that bleaching said fabrics
with the compositions according to the present invention after to washing them with
a detergent composition provides superior bleaching and stain removal performance
with less energy and detergent than if said fabrics are bleached first then washed.
[0028] Indeed, it is speculated that when a fabric is washed with a conventional detergent
composition residual alkalinity is left on the fabrics even when the fabrics is subsequently
rinsed with water. Such alkaline residuality on the fabrics are believed to further
boost the bleaching performance and stain removal performance of the acidic liquid
aqueous persulfate-compositions as described herein when they are contacted to the
fabrics in their diluted form.
[0029] It has further been found that reduced colour damage (i.e., colour change and/or
decoloration) and reduced tensile strength loss are observed when bleaching the fabrics
according to the present invention with a liquid aqueous composition comprising a
persulfate salt and optionally a bleach activator compound.
[0030] The reduced tensile strength loss and reduced colour damage are observed even if
the composition is left to soak with the acidic liquid aqueous composition as described
herein after, upon prolonged periods of time before rinsing the fabrics, e.g. 24 hours.
Actually, formulating the persulfate salt and optionally a bleach activator in a liquid
aqueous composition having a pH below 7, prevents the decomposition (oxidation) of
dyes generally present on the surface of coloured fabrics such as bleach sensitive
dyes and/or metallized dyes including copper-formazan dyes and/or metal-azo dyes,
when the fabrics are bleached therewith according to the process herein.
[0031] A typical issue associated to for example granular persulphate-containing compositions
known in the art (see for example US 3822114) is the fabric and colour damage associated
to residual persulphate that dissolves slowly in the aqueous bath obtained by diluting
such a composition with water. When a slow-dissolving granular persulphate-containing
composition is used to prepare an aqueous bath (soaking bath), the absence of agitation
that typically occurs in hand washing soaking can cause prolonged contact between
the persulphate in a granular form and the fabrics. Thus an advantage of the present
invention is that the fast dissolution of the liquid aqueous composition as used herein
reduces the fabric and colour damage typically associated to the use of granular persulphate-containing
compositions.
[0032] The tensile strength in a fabric may be measured by stretching said fabric until
it breaks. The force needed to break the fabric is the "Ultimate Tensile Stress" and
may be measured with a stress-strain INSTRON ® machine available from INSTRON. The
loss of tensile strength is the difference between the tensile strength of a fabric
taken as a reference, e.g. a fabric which has not been bleached, and the tensile strength
of the same fabric after having been bleached with a composition of the present invention.
A tensile strength loss of zero means that no fabric damage is observed.
[0033] The colour safety can be evaluated visually by comparing side by side fabrics soaked
with a composition of the present invention and a reference composition. Differences
and graduations in colour can be visually assessed and ranked according to Panel Score
Units (PSU) using any suitable scale. PSU data can be handled statistically using
conventional techniques. Alternatively, various types of optical apparatus and procedures
can be used to assess the improvement in colour safety afforded by the present invention.
For example when evaluating colour safety on fabrics measurements with Hunterlab colour
Quest 45/0 apparatus can be used.
[0034] An advantage of the persulfate-containing compositions suitable for use in the process
of bleaching fabrics according to the present invention is that they are physically
and chemically stable upon prolonged periods of storage.
[0035] Chemical stability of these compositions may be evaluated by measuring the concentration
of available oxygen at given storage time after having manufactured the compositions.
By "chemically stable", it is meant herein that the compositions used herein comprising
a persulfate salt or mixtures thereof and optionally an activator compound do not
undergo more than 15% AvO loss, in one month at 25°C and preferably not more than
10%.
[0036] Available oxygen (AvO) loss of a persulfate containing composition can be measured
by titration with potassium permanganate after reduction with a solution containing
ammonium ferrous sulphate. Said stability test method is well known in the art and
is reported, for example, on the technical information sheet of Curox
R commercially available from Interox. Alternatively persulfate concentration can also
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, May 1988, p 793-795).
[0037] By "physically stable" it is meant herein that no phase separation occurs in the
acidic liquid aqueous persulfate-containing compositions used herein for a period
of 7 days at 50°C.
The liquid aqueous compositions used in the process of bleaching fabrics
[0038] The liquid persulfate-containing compositions for use in the process of bleaching
fabrics according to the present invention are liquid compositions as opposed to a
solid or a gas. As used herein "liquid" includes "pasty" compositions. These liquid
compositions herein are aqueous compositions. These liquid compositions according
to the present invention have a pH below 7, preferably from 0.1 to 6, more preferably
from 0.5 to 4, even more preferably from 1 to 3 and most preferably from 1 to 2. Formulating
these compositions in the acidic pH range is critical to the chemical stability of
these compositions upon prolonged periods of storage before their use in the process
of bleaching fabrics according to the present invention.
[0039] The pH of these compositions may be adjusted by any acidifying or alkalinising agents
known to those skilled in the art. Examples of acidifying agents are organic acids
such as citric acid and inorganic acids such as sulphuric acid, sulphonic acid and/or
methanesulphonic acid. Examples of alkalinising agents are sodium hydroxide, potassium
hydroxide and/or sodium carbonate.
Persulfate salt
[0040] As an essential element the liquid aqueous compositions for use in the process of
bleaching fabrics according to the present invention comprise a persulfate salt or
a mixture thereof.
[0041] Suitable persulfate salts include any alkali metal persulfate salt including sodium
persulfate salts and/or potassium persulfate salts. Preferred persulfate salt to be
used herein is the monopersulfate salt. Examples of monopersulfate salts commercially
available are those commercialised by Interox under the trade name Curox®, by Degussa
under the trade name Caroat® or by DuPont under the trade name Oxone®. It is to understand
herein that when the commercially available Curox® , Caroat® and/or Oxone® are used,
the % weights of persulfate salts mentioned herein, refer to the total weight of said
Curox® , Caroat® and/or Oxone® . The active concentration is approximately 1/2 of
the total weight. Other persulfate salts such as dipersulfate salts commercially available
among others from Peroxide Chemie GMBH can be used in the compositions according to
the present invention. Another suitable persulphate salt is ammonium persulphate.
[0042] Typically, the liquid compositions for use in the process of bleaching fabrics according
to the present invention comprise from 0.01% to 50% by weight of the total composition
of the persulfate salt or mixtures thereof, preferably from 0.5% to 20%, more preferably
from 1% to 15% and most preferably from 2% to 10%.
Optional ingredients:
[0043] The liquid aqueous persulfate-containing compositions used in the process of bleaching
fabrics according to the present invention may comprise a variety of optional ingredients
such as bleach activator compounds, surfactants, chelating agents, radical scavengers,
antioxidants, other stabilisers, builders, soil suspenders, polymeric soil release
agents, catalysts, dye transfer agents, solvents, suds controlling agents, brighteners,
perfumes, pigments, dyes and the like.
Bleach activators:
[0044] Suitable bleach activators for use in these liquid persulfate-containing compositions
include aldehyde activator compounds, ketone activator compounds, halide activator
compounds and a mixture thereof.
[0045] By "aldehyde", it is meant herein any compound which contains at least one carbonyl
group and has two hydrogen atoms or carbon atom and a hydrogen atom attached directly
to at least one of the carbonyl carbon atoms.
[0046] By "ketone", it is meant herein any compound which contains at least one carbonyl
group and has two carbon atoms attached directly to at least one of the carbonyl carbon
atoms.
[0047] These compounds can be aliphatic or aromatic substituted or unsubstituted, saturated
or unsaturated, or acyclic, carbocyclic or heterocyclic.
[0048] By "halide", it is meant chloride, bromide and/or iodide.
[0049] By "activator", it is meant herein ketone, aldehyde and halide compounds and mixtures
thereof that react with persulfate salt to form an activated bleaching specie, i.e.
a dioxirane (when the activator compound is ketone or aldehyde) or a hypohalogenite
(when the activator compound is a halide). These activation mechanisms are known in
the art and are for example described in US 3822114.
[0050] Advantageously, when the liquid aqueous compositions used in the process of bleaching
fabrics herein further comprise such a bleach activator, the bleaching performance
and overall stain removal performance is further improved. It is the activated species,
i.e. dioxirane and hypohalogenite, which are thought to greatly enhance the bleaching
in the present invention over persulfate alone or over other activated bleaching system,
e.g. hydrogen peroxide and acetyl triethyl citrate. These activation mechanisms mainly
occur upon dilution of the compositions herein with water and are emphased with the
pH jump in the neutral to alkaline pH range (i.e. around 6 and higher) associated
to this dilution. It is at those pHs that more dioxiranes and/or hypohalogenites are
generated thereby outstandingly improving the bleaching performance of the process
of bleaching fabrics herein.
[0051] Suitable aldehyde activator compounds for use herein include chloral-hydrate, acetaldehyde,
butyraldehyde, benzaldehyde, and/or 4-trimethylammonio benzaldehyde methyl sulfate.
Particularly preferred aldehyde activator compounds for use herein are acetaldehyde,
butyraldehyde and/or, benzaldehyde and most preferred is acetaldehyde. Aldehyde activator
compounds are in general less preferred than the ketone activators compounds as they
may be oxidised during prolonged storage periods.
[0052] For example acetaldehyde may be commercially available from Aldrich.
[0053] Suitable aliphatic ketone activator compounds for use herein include acetacetone,
2,3-hexanedione, trimethylammonio acetone nitrate, 5-diethylbenzylammonio 2-pentanone
nitrate, 5-diethylmethylammonio 2-pentanone nitrate, methyl pyruvate, diethyl keto
malonate, 3-hydroxy-2-butanone, acetol, hexachloracetone, 2,5-hexanedione, phenylacetone,
ethyl levulinate, 3-hydroxy-2-pentanone, acetone, 3-penten-2-one, methyl ethyl ketone,
4-hydroxy-3-methyl-2-butanone, 3-pentanone, and/or 2-heptanone.
[0054] For example acetacetone may be commercially available from Aldrich under its chemical
name.
[0055] Suitable aromatic ketone activator compounds for use herein include hydroxyquinoline,
4-acetyl-1-methylpyridinium nitrate, di-2-pyridyl ketone N-oxide, 2-acetylquinoxaline,
2-acetyl-3-methylquinoxaline oxaline, di-2- pyridyl ketone, 6-acetyl-1,2,4-trimethyl
quinolinium nitrate, 8-hydroxyquinoline N-oxide, methyl phenyl glyoxalate, N-methyl-p-morpholinio
acetophenone methyl sulfate, 3-acetyl pyridine N-oxide, p-nitroacetophenone, m-nitroacetophenone,
sodium p-acetyl benzene sulfonate, p-acetylbenzonitrile, 3,5-dinitroacetophenone,
4-trimethylammonioacetophenone nitrate, 4-methoxy-3-nitroacetophenone, p-chloroacetophenone,
p-diacetylbenzene, N-methyl-p-morpholinio acetophenone nitrate, phenacyltriphenylphosphonium
nitrate, 2-acetyl pyridine, 2-acetyl pyridine N-oxide, 3-acetyl pyridine, 4-acetyl
pyridine, 4-acetyl pyridine N-oxide, 2,6- diacetyl pyridine, 3-acetyl pyridine N-oxide,
and/or triacetylbenzene.
[0056] Suitable cyclic ketone activator compounds for use herein include cyclohexanone,
2-methylcyclohexanone, 2,6-dimethyl cyclohexanone, 3-methyl cyclohexanone, 4-ethyl
cyclohexanone, 4-t-butyl cyclohexanone, 4,4-dimethyl cyclohexanone, methyl 4-oxo-cyclohexanone
carboxylate, sodium 4-oxo-cyclohexanone carboxylate, 2-trimethylammoniocyclohexanone
nitrate, 4-trimethylammonio cyclohexanone nitrate, 3 oxo-cyclohexyl acetic acid, cycloheptanone,
1,4-cyclohexadione, dehydrochloric acid, tropinone methonitrate, N-methyl-3-oxoquinuclidinium
nitrate, cyclooctanone and/or cyclopentanone.
[0057] For example cyclohexanone may be commercially available from Aldrich under its chemical
name.
[0058] Suitable heterocyclic ketone activator compounds for use herein include, 2,2,6,6-tetramethyl-4-piperidone
hydrate, 1-methyl-4-piperidone N-oxide, N-carbethoxy 4-piperidone, tetrahydrothiopyran-4-one
methonitrate, tetrahydrothiopyran-4-one S,S- dioxide, tetrahydrothiopyran-3-one,S,S,-dioxide,
and/or 4-oxacyclohexanone.
[0059] All of the above-described aldehyde and ketone examples are all either commercially
available or can obviously be synthesized by the skilled artisan having before him
the teaching of the prior art Gardini et al.,
J. Chem. Soc.(C), (1970) page 929 and Lyle et al.,
J. Org. Chem., Vol. 24 (March, 1959), page 342 are examples of such art and are hereby incorporated herein
by reference. Also a method for the synthesis of oxopiperidinium compounds is described
in "S.E. Denmark, D.C. Forbes, D.S. Hays, J.S. De Pue and R.G. Wilde, J.Org. Chem.
1995, 60, 1391-1407".
[0060] Particularly preferred bleach activators for use herein are the ketone activator
compounds and highly preferred are the ketones activator compounds bearing a positive
charge.
[0061] Particularly suitable ketone activator compounds bearing a positive charge are for
example oxopiperidinium salts having the following formula:

wherein the carbonyl group >C=O, can be either at the 2, 3 or at the 4 position of
the oxopiperidinium; R1 and R2 are each independently a substituted or unsubstituted
hydrocarbon chain having from 1 to 20 carbon atoms, preferably a substituted or unsubstituted
alkyl or alkenyl or alkinyl group containing from 1 to 20 carbon atoms, preferably
from 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group containing
from 6 to 10 atoms, or a C1-C20 alkyl aryl group wherein the aryl group contains from
6 to 10 carbon atoms; X
- can be any negative ion, e.g., triflate, tosilate, mesilate, nitrate, more preferred
is triflate, mesilate, tosilate and most preferred is triflate and the oxopiperidinium
ring can be mono or polysubstituted at the 2,3,5, or 6 positions by one or more substituents
as defined for R1 or R2 above or a halogen atom.
[0062] Examples of oxopiperidinium salts particularly suitable for use herein include 1,1-dimethyl-3-oxopiperidinium
nitrate, 1,1-dimethyl-4-oxopiperidinium triflate, 1,1-dimethyl-3-oxopiperidinium triflate,
1,1-dimethyl-4-oxopiperidinium nitrate, 1-benzyl-4-piperidone methonitrate, 1-t-butyl-1-methyl-4-oxopiperidinium
nitrate, 1-(4-dodecylbenzyl) 1-methyl-4 oxopiperidinium chloride, 3-(N-methyl-4 oxopiperidinium)-propane
sulfonate, 1-allyl-1-methyl-4- oxopiperidinium chloride, 1-methyl-1-(1-naphthyl-methyl)-4-
oxopiperidinium chloride, 1-methyl-1-pentamethylbenzyl-4-oxopiperidinium chloride,
N,N'-dimethyl-N,N'-phenylene dimethylene -bis(4- oxopiperidinlum nitrate), 1-benzyl-1-methyl-4-oxopiperidinium
triflate, 1-benzyl-1-methyl-3-oxopiperidinium triflate, 1-benzyl-1-methyl-4-oxopiperidinium
nitrate, 1-dodecyl-1-methyl-4-oxopiperidinium nitrate, 1-octyl-1-methyl-4-oxopiperidinium
nitrate, 1-nonyl-1-methyl-4-oxopiperidinium nitrate or a mixture thereof.
[0063] Other suitable ketone activator compounds bearing a positive charge suitable for
use herein are for example the ammonium acetophenone salts according to the following
formula:

wherein the ammonium group can be either at the 2 , at the 3 position or at the 4
position ; R1, R2 and R3 are each independently a substituted or unsubstituted hydrocarbon
group having from 1 to 20 carbon atoms, preferably a substituted or unsubstituted
alkyl, or alkenyl or alkinyl group containing from 1 to 20 carbon atoms, preferably
from 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group containing
from 6 to 10 atoms or a C1-C20 alkyl aryl group wherein the aryl group contains from
6 to 10 carbon atoms; R4 is a substituted or nonsubstituted halogenate alkyl group
having from 1 to 20 carbon atoms, preferably from 1 to 12 carbon atoms and more preferably
is methyl, or trifluoromethyl or trichloromethyl or tribromomethyl, ;X
- can be any negative ion, e.g., triflate, tosilate, mesilate, or nitrate and the benzenic
ring can be substituted at the 2, 3 and/or 4 positions by one or more substituents
as defined for R1 , R2 or R3 as described above or a halogen atom.
[0064] Examples of such ammonium acetophenone salts for use herein include 4-trimethylammonium
acetophenone nitrate, 2-trimethylammoniumacetophenone nitrate, 4-triethylammoniumacetophenone
mesilate, 3-trimethylammoniumacetophenone mesilate, trihalogenatedmethylphenyl ketone
like trifluoromethylphenylketone, trichloromethylphenylketone, tribromomethylphenylketone
or a mixture thereof.
[0065] Suitable halide activator compounds for use herein include chloride, bromide, iodide
and mixtures thereof. Particularly preferred halide activator compounds for use herein
is an alkali metal of chloride. For example sodium chloride may be commercially available
from Aldrich under its chemical name.
[0066] Typically, the compositions herein comprise up to 10% by weight of the total composition
of said ketone, aldehyde and/or halide activator compound, preferably from 0.05% to
5%, more preferably from 0.1% to 2% and most preferably from 0.2% to 1.5%.
Surfactants:
[0067] The liquid persulfate-containing compositions suitable for use in the process of
bleaching fabrics herein may comprise a surfactant or a mixture thereof including
nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants
and/or amphoteric surfactants. Typically these surfactants do not contain functional
groups that can be oxidised by the persulphate salt, or that can substantially hydrolize
at a low pH.
[0068] Typically, the compositions according to the present invention may comprise from
0.01% to 50% by weight of the total composition of a surfactant or a mixture thereof,
preferably from 0.1% to 30 % and more preferably from 0.2% to 10%.
[0069] Suitable anionic surfactants for use in the compositions herein include water-soluble
salts or acids of the formula ROSO
3M wherein R preferably is a C
10-C
24 hydrocarbyl, preferably an alkyl or hydroxyalkyl having a C
10-C
20 alkyl component, more preferably a C
12-C
18 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 quaternary ammonium cations derived from alkylamines
such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).
Typically, alkyl chains of C
12-
16 are preferred for lower wash temperatures (e.g., below about 50°C) and C
16-
18 alkyl chains are preferred for higher wash temperatures (e.g., above about 50°C).
[0070] Other suitable anionic surfactants for use herein are water-soluble salts or acids
of the formula RO(A)
mSO
3M wherein R is an unsubstituted C
10-C
24 alkyl or hydroxyalkyl group having a C
10-C
24 alkyl component, preferably a C
12-C
20 alkyl or hydroxyalkyl, more preferably C
12-C
18 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 C
12-C
18 alkyl polyethoxylate (1.0) sulfate, C
12-C
18E(1.0)M), C
12-C
18 alkyl polyethoxylate (2.25) sulfate, C
12-C
18E(2.25)M), C
12-C
18 alkyl polyethoxylate (3.0) sulfate C
12-C
18E(3.0), and C
12-C
18 alkyl polyethoxylate (4.0) sulfate C
12-C
18E(4.0)M), wherein M is conveniently selected from sodium and potassium.
[0071] Other particularly suitable anionic surfactants for use herein are alkyl sulphonates
including water-soluble salts or acids of the formula RSO
3M wherein R is a C
6-C
22 linear or branched, saturated or unsaturated alkyl group, preferably a C
12-C
18 alkyl group and more preferably a C
14-C
16 alkyl group, 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 quaternary ammonium cations derived from alkylamines
such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).
[0072] Suitable alkyl aryl sulphonates for use herein include water- soluble salts or acids
of the formula RSO
3M wherein R is an aryl, preferably a benzyl, substituted by a C
6-C
22 linear or branched saturated or unsaturated alkyl group, preferably a C
12-C
18 alkyl group and more preferably a C
14-C
16 alkyl group, and M is H or a cation, e.g., an alkali metal cation (e.g., sodium,
potassium, lithium, calcium, magnesium etc) or ammonium or substituted ammonium (e.g.,
methyl-, dimethyl-, and trimethyl ammonium cations and quatemary ammonium cations,
such as tetramethyl-ammonium and dimethyl piperdinium cations and quaternary ammonium
cations derived from alkylamines such as ethylamine, diethylamine, triethylamine,
and mixtures thereof, and the like).
[0073] The alkylsulfonates and alkyl aryl sulphonates for use herein include primary and
secondary alkylsulfonates and primary and secondary alkyl aryl sulphonates. By "secondary
C6-C22 alkyl or C6-C22 alkyl aryl sulphonates", it is meant herein that in the formula
as defined above, the SO3M or aryl-SO3M group is linked to a carbon atom of the alkyl
chain being placed between two other carbons of the said alkyl chain (secondary carbon
atom).
[0074] For example C14-C16 alkyl sulphonate salt is commercially available under the name
Hostapur ® SAS from Hoechst and C8-alkylsulphonate sodium salt is commercially available
under the name Witconate NAS 8® from Witco SA. An example of commercially available
alkyl aryl sulphonate is Lauryl aryl sulphonate from Su.Ma. Particularly preferred
alkyl aryl sulphonates are alkyl benzene sulphonates commercially available under
trade name Nansa® available from Albright&Wilson.
[0075] 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,
C
8-C
24 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, C
8-C
24 alkylpolyglycolethersulfates (containing up to 10 moles of ethylene oxide); alkyl
ester sulfonates such as C
14-16 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
C
12-C
18 monoesters) diesters of sulfosuccinate (especially saturated and unsaturated C
6-C
14 diesters), 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(CH
2CH
2O)
kCH
2COO-M
+ wherein R is a C
8-C
22 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).
[0076] Other particularly suitable anionic surfactants for use herein are alkyl carboxylates
and alkyl alkoxycarboxylates having from 4 to 24 carbon atoms in the alkyl chain,
preferably from 8 to 18 and more preferably from 8 to 16, wherein the alkoxy is propoxy
and/or ethoxy and preferably is ethoxy at an alkoxylation degree of from 0.5 to 20,
preferably from 5 to 15. Preferred alkylalkoxycarboxylate for use herein is sodium
laureth 11 carboxylate (i.e., RO(C

H

O)

-CN

COONa, with R= C12-C14) commercially available under the name Akyposoft® 100NV from
Kao Chemical Gbmh.
[0077] Suitable amphoteric surfactants for use herein include amine oxides having the following
formula R
1 R
2R
3NO wherein each of R1, R2 and R3 is independently a saturated substituted or unsubstituted,
linear or branched hydrocarbon chains of from 1 to 30 carbon atoms. Preferred amine
oxide surfactants to be used according to the present invention are amine oxides having
the following formula R
1 R
2R
3NO wherein R1 is an hydrocarbon chain comprising from 1 to 30 carbon atoms, preferably
from 6 to 20, more preferably from 8 to 16, most preferably from 8 to 12, and wherein
R2 and R3 are independently substituted or unsubstituted, linear or branched hydrocarbon
chains comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms, and
more preferably are methyl groups. R1 may be a saturated substituted or unsubstituted
linear or branched hydrocarbon chain. Suitable amine oxides for use herein are for
instance natural blend C8-C10 amine oxides as well as C12-C16 amine oxides commercially
available from Hoechst.
[0078] Suitable zwitterionic surfactants for use herein contain both a cationic hydrophilic
group, i.e., a quaternary ammonium group, and anionic hydrophilic group on the same
molecule at a relatively wide range of pH's. The typical anionic hydrophilic groups
are carboxylates and sulfonates, although other groups like sulfates, phosphonates,
and the like can be used. A generic formula for the zwitterionic surfactants to be
used herein is:
R
1-N
+(R
2)(R
3)R
4X
-
wherein R
1 is a hydrophobic group; R
2 is hydrogen, C
1-C
6 alkyl, hydroxy alkyl or other substituted C
1-C
6 alkyl group; R
3 is C
1-C
6 alkyl, hydroxy alkyl or other substituted C
1-C
6 alkyl group which can also be joined to R
2 to form ring structures with the N, or a C
1-C
6 carboxylic acid group or a C
1-C
6 sulfonate group; R
4 is a moiety joining the cationic nitrogen atom to the hydrophilic group and is typically
an alkylene, hydroxy alkylene, or polyalkoxy group containing from 1 to 10 carbon
atoms; and X is the hydrophilic group which is a carboxylate or sulfonate group.
[0079] Preferred hydrophobic groups R
1 are aliphatic or aromatic, saturated or unsaturated, substituted or unsubstituted
hydrocarbon chains that can contain linking groups such as amido groups, ester groups.
More preferred R
1 is an alkyl group containing from 1 to 24 carbon atoms, preferably from 8 to 18,
and more preferably from 10 to 16. These simple alkyl groups are preferred for cost
and stability reasons. However, the hydrophobic group R
1 can also be an amido radical of the formula R
a-C(O)-NH-(C(R
b)
2)
m, wherein R
a is an aliphatic or aromatic, saturated or unsaturated, substituted or unsubstituted
hydrocarbon chain, preferably an alkyl group containing from 8 up to 20 carbon atoms,
preferably up to 18, more preferably up to 16, R
b is selected from the group consisting of hydrogen and hydroxy groups, and m is from
1 to 4, preferably from 2 to 3, more preferably 3, with no more than one hydroxy group
in any (C(R
b)
2) moiety.
[0080] Preferred R
2 is hydrogen, or a C
1-C
3 alkyl and more preferably methyl. Preferred R
3 is a C
1-C
4 carboxylic acid group or C1-C4 sulfonate group, or a C
1-C
3 alkyl and more preferably methyl. Preferred R
4 is (CH2)
n wherein n is an integer from 1 to 10, preferably from 1 to 6, more preferably is
from 1 to 3.
[0081] Some common examples of betaine/sulphobetaine are described in U.S. Pat. Nos. 2,082,275,
2,702,279 and 2,255,082, incorporated herein by reference.
[0082] Examples of particularly suitable alkyldimethyl betaines include coconut-dimethyl
betaine, lauryl dimethyl betaine, decyl dimethyl betaine, 2-(N-decyl-N, N-dimethyl-ammonia)acetate,
2-(N-coco N, N-dimethylammonio) acetate, myristyl dimethyl betaine, palmityl dimethyl
betaine, cetyl dimethyl betaine, stearyl dimethyl betaine. For example Coconut dimethyl
betaine is commercially available from Seppic under the trade name of Amonyl 265®.
Lauryl betaine is commercially available from Albright & Wilson under the trade name
Empigen BB/L®.
[0083] Examples of amidobetaines include cocoamidoethylbetaine, cocoamidopropyl betaine
or C10-C14 fatty acylamidopropylene(hydropropylene)sulfobetaine. For example C10-C14
fatty acylamidopropylene(hydropropylene)sulfobetaine is commercially available from
Sherex Company under the trade name "Varion CAS® sulfobetaine".
[0084] A further example of betaine is Lauryl-immino-dipropionate commercially available
from Rhone-Poulenc under the trade name Mirataine H2C-HA ®.
[0085] Suitable cationic surfactants for use herein include derivatives of quaternary ammonium,
phosphonium, imidazolium and sulfonium compounds. Preferred cationic surfactants for
use herein are quaternary ammonium compounds wherein one or two of the hydrocarbon
groups linked to nitrogen are a saturated, linear or branched alkyl group of 6 to
30 carbon atoms, preferably of 10 to 25 carbon atoms, and more preferably of 12 to
20 carbon atoms, and wherein the other hydrocarbon groups (i.e. three when one hydrocarbon
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 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. Preferred quaternary ammonium compounds suitable
for use herein are non-chloride/non halogen quaternary ammonium compounds. The counterion
used in said quaternary ammonium compounds are compatible with any persulfate salt
and are selected from the group of methyl sulfate, or methylsulfonate, and the like.
[0086] Particularly preferred for use in the compositions of the present invention are trimethyl
quaternary ammonium compounds like myristyl trimethylsulfate, cetyl trimethylsulfate
and/or tallow trimethylsulfate. Such trimethyl quaternary ammonium compounds are commercially
available from Hoechst, or from Albright & Wilson under the trade name EMPIGEN CM®.
[0087] Amongst the nonionic surfactants, alkoxylated nonionic surfactants and especially
ethoxylated nonionic surfactants are suitable for use herein. Particularly preferred
nonionic surfactants for use herein are the capped alkoxylated nonionic surfactants
as they have improved stability to the persulfate salts.
[0088] Suitable capped alkoxylated nonionic surfactants for use herein are according to
the formula:
wherein R1 is a C8-C24 linear or branched alkyl or alkenyl group, aryl group, alkaryl group, preferably
R1 is a C8-C18 alkyl or alkenyl group, more preferably a C10-C15 alkyl or alkenyl group, even more preferably a C10-C15 alkyl group;
wherein R2 is a C1 -C10 linear or branched alkyl group, preferably a C2-C10 linear or branched alkyl group;
wherein R3 is a C1-C10 alkyl or alkenyl group, preferably a C1-C5 alkyl group, more preferably methyl;
and wherein n and m are integers independently ranging in the range of from 1 to 20,
preferably from 1 to 10, more preferably from 1 to 5; or mixtures thereof.
[0089] These surfactants are commercially available from BASF under the trade name Plurafac®,
from HOECHST under the trade name Genapol® or from ICI under the trade name Symperonic®.
Preferred capped nonionic alkoxylated surfactants of the above formula are those commercially
available under the tradename Genapol® L 2.5 NR from Hoechst, and Plurafac® from BASF.
Cheating agents:
[0090] The liquid aqueous persulfate-containing compositions suitable for use in the process
of bleaching fabrics herein 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.
[0091] The presence of chelating agents contribute to further enhance the chemical stability
of the compositions. A cheating agent may be also desired in the compositions herein
as it allows to increase the ionic strength of the compositions and thus their stain
removal and bleaching performance on various surfaces.
[0092] 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 cheating 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®.
[0093] 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.
[0094] 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.
[0095] Suitable amino carboxylates for use 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 diacetic
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).
[0096] Further carboxylate chelating agents for use herein include salicylic acid, aspartic
acid, glutamic acid, glycine, malonic acid or mixtures thereof.
[0097] 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.
[0098] Particularly preferred cheating 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.
[0099] Typically, the liquid aqueous persulfate-containing compositions suitable for use
in the process of bleaching fabrics herein 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:
[0100] The liquid aqueous persulfate-containing compositions suitable for use in the process
of bleaching fabrics herein may comprise a radical scavenger or a mixture thereof.
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 ®. Radical scavengers when used, are typically present
herein in amounts ranging from up to 10% by weight of the total composition and preferably
from 0.001% to 0.5% by weight.
[0101] The presence of radical scavengers may contribute to the chemical stability of the
bleaching compositions herein as well as to the safety profile of these compositions.
Test methods:
[0102] The bleaching performance may be evaluated by the following test methods on various
type of bleachable stains.
[0103] A suitable test method for evaluating the bleaching performance on a soiled fabric
under soaking conditions is the following: A composition according to the present
invention is diluted with water typically at a dilution level of 1 to 100 ml/L, preferably
20 ml/L (composition :water), then the soiled fabrics are soaked in it for 20 minutes
to 6 hours and then rinsed. Alternatively the bleaching composition can be used in
a washing machine at a dilution level of typically at a dilution level of 1 to 100
ml/L (composition :water). In the washing machine the soiled fabrics are washed at
a temperature of from 30° to 70°C for 10 to 100 minutes and then rinsed. The reference
composition in this comparative test undergoes the same treatment. Soiled fabrics/swatches
with for example tea, coffee and the like may be commercially available from E.M.C.
Co. Inc..
[0104] The bleaching performance is then evaluated by comparing side by side the soiled
fabrics treated with the composition used in the present invention with those treated
with the reference, e.g., the same composition but comprising another bleaching system,
e.g., hydrogen peroxide and acetyl triethyl citrate at equal bleaching agents total
level. A visual grading may be used to assign difference in panel units (psu) in a
range from 0 to 4.
[0105] For stain removal performance on various stains the same test method is followed
but on enzymatic and greasy stains.
Examples
[0106] Following liquid aqueous persulfate compositions were made by mixing the listed ingredients
in the listed proportions (weight % unless otherwise specified).
Compositions (% weight) |
I |
II |
III |
IV |
V |
Akyposoft 100 NV® |
0.5 |
0.5 |
- |
0.3 |
0.4 |
Curox® |
3 |
2 |
4 |
4.3 |
5 |
Trifluoromethylphenylketone |
0.5 |
- |
- |
0.3 |
- |
Acetoacetone |
- |
0.4 |
- |
- |
0.4 |
HEDP |
0.1 |
0.05 |
0.16 |
0.1 |
- |
BHT |
0.05 |
- |
- |
- |
0.1 |
Propyl gallate |
- |
0.1 |
- |
0.05 |
- |
NaCl |
- |
- |
0.1 |
0.5 |
- |
NaBr |
- |
- |
- |
- |
1.0 |
Water and minors |
up to 100% |
Alkanizing agent up to pH |
2 |
2.5 |
4 |
4 |
1.5 |
Compositions (% weight) |
VI |
VII |
VIII |
IX |
X |
XI |
Akyposoft 100 NV® |
0.5 |
0.5 |
0.5 |
0.2 |
0.2 |
- |
Curox® |
5 |
7 |
10 |
10 |
6 |
9.5 |
Acetylacetone |
0.5 |
0.5 |
0.5 |
- |
- |
- |
N,N dymethyl-4 |
|
|
|
|
|
|
-oxopiperidinium nitrate |
- |
- |
- |
0.5 |
0.5 |
- |
Propyl gallate |
0.05 |
0.05 |
0.1 |
0.1 |
0.05 |
- |
Water and minors |
up to 100% |
pH |
2 |
1.8 |
1.5 |
1.5 |
2 |
2 |
Compositions (% weight) |
XII |
XIII |
XIV |
XV |
XVI |
XVII |
Akyposoft 100 NV® |
0.5 |
0.5 |
0.5 |
0.2 |
0.2 |
0.2 |
Curox® |
5 |
7 |
10 |
10 |
6 |
9.5 |
Cyclohexanone |
0.5 |
- |
0.5 |
0.5 |
- |
- |
N,N dymethyl-3 |
- |
0.5 |
- |
- |
0.5 |
- |
-oxopiperidinium nitrate |
|
|
|
|
|
|
Propyl gallate |
0.05 |
0.05 |
0.1 |
0.1 |
0.05 |
0.1 |
Water and minors |
up to 100% |
pH |
2 |
1.8 |
1.5 |
1.5 |
2 |
2 |
Compositions (% weight) |
XVIII |
XIX |
XX |
XXI |
XXII |
XXIII |
Witconate NAS 8 (40% active)® |
5 |
5 |
5 |
5 |
5 |
- |
Curox® |
9.5 |
9.5 |
9.5 |
9.5 |
9.5 |
9.5 |
N,N dymethyl-4 |
0.5 |
1 |
0.1 |
0.5 |
0.5 |
- |
-oxopiperidinium triflate |
|
|
|
|
|
|
HEDP |
0.1 |
0.2 |
0.1 |
- |
- |
0.1 |
BHT |
0.05 |
0.05 |
0.1 |
0.1 |
0.05 |
0.05 |
Water and minors |
up to 100% |
pH |
1.5 |
1.5 |
1.5 |
1.5 |
1.5 |
1.5 |
Compositions (% weight) |
XXIV |
XXV |
Witconate NAS 8 (40% active)® |
5 |
5 |
Curox® |
9.5 |
9.5 |
Cycloheptanone |
0.5 |
0.5 |
HEDP |
- |
0.1 |
BHT |
- |
0.05 |
Water and minors |
up to 100% |
pH |
1.5 |
1.5 |
Akyposoft 100 NV® is a C12-C14 alkyl ethoxycarboxylate (EO10) commercially available
from Kao Chemicala Gmbh.
BHT is di-tert butyl hydroxy toluene.
HEDP is ethane 1-hydroxy diphosphonate commercially available from Monsanto under
the serie Dequest®.
Cycloheptanone is commercially available from Aldrich.
Witconate NAS 8® is C8 alkyl sulphonate commercially available from Witco SA.
Curox® is a triple salt of potassium monopersulfate, potassium sulphate and potassium
bisulphate commercially available from Interox.
The following processes of bleaching fabrics will illustrate the present invention:
Example 1
[0107] 100 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 20 minutes before being rinsed with water.
Example 2
[0108] 200 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 20 minutes before being rinsed with water for 20 minutes.
Example 3
[0109] 300 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 20 minutes before being rinsed with water for 20 minutes.
Example 4
[0110] 100 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 1 hour before being rinsed with water for 20 minutes.
Example 5
[0111] 100 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 6 hours before being rinsed with water for 20 minutes.
Example 6
[0112] 100 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 24 hours before being rinsed with water for 20 minutes.
Example 7
[0113] 100 ml of a liquid persulphate composition as exemplified above (compositions I to
XXV) was diluted in 5L of water. Then soiled fabrics were contacted with the aqueous
bath so obtained for 1 hour before being rinsed with water for 20 minutes. Finally
the fabrics so bleached were contacting for 1 hour with 40g of Dash Futur® diluted
in 5L of water and subsequently rinsed with water.
Example 8
[0114] 140 ml of Ariel a mano® were diluted with 5 liters of water. The soiled fabrics were
contacted to the soaking solution so obtained for 1 hour and subsequently rinsed.
Then 100 ml of a liquid persulphate composition as exemplified above (compositions
I to XXV) was diluted in 5L of water. Then the fabrics were contacted with the aqueous
bath so obtained for 1 hour before being rinsed with water for 20 minutes.
Example 9
[0115] 100 ml of a liquid persulfate-containing composition as exemplified above (compositions
I to XXV) was diluted in 5L of water to obtain an aqueous bath to which the soiled
fabrics were contacted for 20 minutes. The fabrics were then rinsed for 2 minutes
than washed in a washing machine (e.g. San Giorgio 352 ZX®, main cycle) with 225g
of Dash Futur®.
[0116] All the above processes provide excellent bleaching performance as well as effective
stain removal performance when bleaching fabrics while being safe to the fabrics and
the colours.
1. A process of bleaching a fabric which comprises the steps of :
- diluting in an aqueous bath a liquid aqueous composition in its neat form, having
a pH below 7 and comprising a persulfate salt,
- contacting said fabric with said aqueous bath comprising said liquid composition,
and subsequently rinsing said fabric with water.
2. A process according to claim 1 wherein the fabric is left to soak in said aqueous
bath comprising said liquid aqueous composition for a period of time ranging from
1 minute to 24 hours, preferably from 3 minutes to 12 hours, more preferably from
4 minutes to 6 hours and most preferably 4 minutes to 15 minutes.
3. A process according to any of the preceding claims wherein the composition is diluted
with water at a dilution level up to 500 times its weight, preferably from 5 to 200
times and more preferably from 10 to 80 times.
4. A process according to any of the preceding claims wherein said fabric is washed with
a laundry detergent composition comprising at least one surface active agent before
the step of contacting said fabrics with said aqueous bath comprising said liquid
aqueous composition and/or in the step where said fabrics are contacted with said
aqueous bath and/or after the step where said fabrics are contacted with said aqueous
bath and before the rinsing step and/or after the rinsing step.
5. A process according to the preceding claims wherein said liquid aqueous composition
comprises from 0.01% to 50% by weight of the total composition of a persulfate salt
or mixtures thereof, preferably from 0.5% to 20%, more preferably from 1% to 15% and
most preferably from 2% to 10%.
6. A process according to any of the preceding claims wherein in said liquid composition
said persulfate salt is a monopersulfate salt, preferably sodium monopersulfate and/or
potassium monopersulfate.
7. A process according to any of the preceding claims wherein said liquid composition
further comprises up to 10% by weight of the total composition of a ketone, aldehyde
and/or halide activator compound, preferably from 0.05% to 5%, more preferably from
0.1% to 2% and most preferably from 0.2% to 1.5%.
8. A process according to claim 7 wherein said activator is an oxopiperidinium salt,
an ammonium acetophenone salt, acetacetone, 2,3-hexanedione, trimethylammonio acetone
nitrate, 5-diethylbenzylammonio 2-pentanone nitrate, 5-diethylmethylammonio 2-pentanone
nitrate, methyl pyruvate, diethyl keto malonate, 3-hydroxy-2-butanone, acetol, hexachloracetone,
2,5- hexanedione, phenylacetone, ethyl levulinate, 3-hydroxy-2-pentanone, acetone,
3-penten-2-one, methyl ethyl ketone, 4-hydroxy-3-methyl-2-butanone, 3-pentanone, 2-heptanone,
hydroxyquinoline, 4-acetyl-1-methylpyridinium nitrate, di-2-pyridyl ketone N-oxide,
2-acetylquinoxaline, 2-acetyl-3-methylquinoxaline oxaline, di-2-pyridyl ketone, 6-acetyl-1,2,4-trimethyl
quinolinium nitrate, 8-hydroxyquinoline N-oxide, methyl phenyl glyoxalate, N-methyl-p-morpholinio
acetophenone methyl sulfate, 3-acetyl pyridine N-oxide, p-nitroacetophenone, m-nitroacetophenone,
sodium p-acetyl benzene sulfonate, p-acetylbenzonitrile, 3,5-dinitroacetophenone,
4-trimethylammonioacetophenone nitrate, 4-methoxy-3-nitroacetophenone, p-chloroacetophenone,
p-diacetylbenzene, N-methyl-p-morpholinio acetophenone nitrate, phenacyltriphenylphosphonium
nitrate, 2-acetyl pyridine, 2-acetyl pyridine N-oxide, 3-acetyl pyridine, 4-acetyl
pyridine, 4-acetyl pyridine N-oxide, 2,6- diacetyl pyridine, 3-acetyl pyridine N-oxide,
triacetylbenzene, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethyl cyclohexanone,
3-methyl cyclohexanone, 4-ethyl cyclohexanone, 4-t-butyl cyclohexanone, 4,4-dimethyl
cyclohexanone, methyl 4-oxo-cyclohexanone carboxylate, sodium 4-oxo-cyclohexanone
carboxylate, 2-trimethylammoniocyclohexanone nitrate, 4-trimethylammonio cyclohexanone
nitrate, 3 oxo-cyclohexyl acetic acid, cycloheptanone, 1,4-cyclohexadione, dehydrochloric
acid, tropinone methonitrate, N-methyl-3-oxoquinuclidinium nitrate, cyclooctanone,
cyclopentanone, 2,2,6,6-tetramethyl-4-piperidone hydrate, 1-methyl-4-piperidone N-oxide,
N-carbethoxy 4-piperidone, tetrahydrothiopyran-4-one methonitrate, tetrahydrothiopyran-4-one
S,S- dioxide, tetrahydrothiopyran-3-one,S,S,-dioxide, 4-oxacyclohexanone, or a mixture
thereof.
9. A process according to any of the preceding claims 7 or 8 wherein in said liquid aqueous
composition said bleach activator is an oxopiperidinium salt having the following
formula:

wherein the carbonyl group >C=O, can be either at the 2, 3 or at the 4 position of
the oxopiperidinium; R1 and R2 are each independently a substituted or unsubstituted
hydrocarbon chain having from 1 to 20 carbon atoms, preferably a substituted or unsubstituted
alkyl or alkenyl or alkinyl group containing from 1 to 20 carbon atoms, preferably
from 1 to 12, or a substituted or unsubstituted aryl group containing from 6 to 10
atoms, or a C1-C20 alkyl aryl group wherein the aryl group contains from 6 to 10 carbon
atoms; X
- can be any negative ion, e.g., triflate, tosilate, mesiltae, nitrate, more preferred
is triflate, mesilate, tosilate and most preferred is triflate and the oxopiperidinium
ring can be mono or polysubstituted at the 2,3,5, or 6 positions by one or more substituents
as defined for R1 or R2 or a halogen atom and/or an ammonium acetophenone salt according
to the following formula:

wherein the ammonium group can be either at the 2, at the 3 position or at the 4
position ; R1, R2 and R3 are each independently a substituted or unsubstituted hydrocarbon
group having from 1 to 20 carbon atoms, preferably a substituted or unsubstituted
alkyl, or alkenyl or alkinyl group containing from 1 to 20 carbon atoms, preferably
from 1 to 12, or a substituted or unsubstituted aryl group containing from 6 to 10
atoms or a C1-C20 alkyl aryl group wherein the aryl group contains from 6 to 10 carbon
atoms; R4 is an alkyl group having from 1 to 20 carbon atoms, preferably from
1 to
12 and more preferably is methyl, or trifluoromethyl, trichloromethyl or tribromomethyl;
X
- can be any negative ion, e.g., triflate, tosilate, mesilate, or nitrate and the benzenic
ring can be substituted at the 2, 3 and/or 4 positions by one or more substituents
as defined for R1, R2 or R3 as described above or a halogen atom.
10. A process according to any of the preceding claims 7 to 9, wherein in said liquid
aqueous composition said bleach activator is 1,1-dimethyl-3-oxopiperidinium nitrate,
1,1-dimethyl-4-oxopiperidinium triflate, 1,1-dimethyl-3-oxopiperidinium triflate,
1,1-dimethyl-4-oxopiperidinium nitrate, 1-benzyl-4-piperidone methonitrate, 1-t-butyl-1-methyl-4-oxopiperidinium
nitrate, 1-(4-dodecylbenzyl) 1-methyl-4 oxopiperidinium chloride, 3-(N-methyl-4 oxopiperidinium)-propane
sulfonate, 1-allyl-1-methyl-4-oxopiperidinium chloride, 1-methyl-1-(1-naphthyl-methyl)-4-oxopiperidinium
chloride, 1-methyl-1-pentamethylbenzyl- 4-oxopiperidinium chloride, N,N'-dimethyl-N,N'-phenylene
dimethylene - bis(4- oxopiperidinlum nitrate), 1-benzyl-1-methyl-4-oxopiperidinium
triflate, 1-benzyl-1-methyl-3-oxopiperidinium triflate, 1-benzyl-1-methyl-4-oxopiperidinium
nitrate, 1-dodecyl-1-methyl-4-oxopiperidinium nitrate, 1-octyl-1-methyl-4-oxopiperidinium
nitrate, 1-nonyl-1-methyl-4-oxopiperidinium nitrate, 4-trimethylammonium acetophenone
nitrate, 2-trimethylammoniumacetophenone nitrate, 4-triethylammoniumacetophenone mesilate,
3-trimethylammoniumacetophenone mesilate, trihalogenatedmethylphenyl ketone or a mixture
thereof.
11. A process according to any of the preceding claims wherein said liquid composition
has a pH in the range from 0.1 to 6, more preferably from 0.5 to 4, even more preferably
from 1 to 3 and most preferably from 1 to 2.
12. A process according to any of the preceding claims wherein said liquid composition
further comprises at least an optional ingredient selected from the group consisting
of chelating agents, radical scavengers, builders, surfactants, antioxidants, stabilisers,
soil suspenders, polymeric soil release agents, catalysts, dye transfer agents, solvents,
suds controlling agents, brighteners, perfumes, dyes, pigments and mixtures thereof.
13. The use of a liquid aqueous bleaching composition having a pH below 7 and comprising
a persulfate salt and optionally a bleach activator compound being an aldehyde, ketone
and/or halide activator compound for the bleaching of fabrics, for reducing the loss
of tensile strength in said fabrics.
14. The use of a liquid aqueous bleaching composition having a pH below 7 and comprising
a persulfate salt and optionally a bleach activator compound being an aldehyde, ketone
and/or halide activator compound for the bleaching of coloured fabrics, for reducing
the colour damage to said fabrics.