Note: Descriptions are shown in the official language in which they were submitted.
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1
LAUNDRY PRETREATMENT WITH PEROXIDE BLEACHES CONTAINING CHELATORS
FOR IRON, COPPER OR MANGANESE FOR REDUCED FABRIC DAMAGE
Technical field
The present invention relates to the pretreatment of soiled fabrics, to
compositions suitable to be used as pretreater, and to a pretreatment
process.
Back4round
Peroxygen bleach-containing compositions have been extensively
described in laundry applications as laundry detergents, laundry additives
or even laundry pretreaters.
Indeed, it is known to use such peroxygen bleach-containing compositions
in laundry pretreatment applications to boost the removal of encrusted
stains/soils which are otherwise particularly difficult to remove such as
grease, coffee, tea, grass, mud/clay-containing soils and the like. However,
we have found that a drawback associated with such peroxygen bleach-
containing compositions is that said compositions may damage fabrics
when used in pretreatment application, i.e. when applied directly onto the
CA 02213633 2001-05-02
2
fabrics, and left to act onto said fabrics for prolonged periods of time
before
washing said fabrics.
It is thus an asPe~t of the present invention to provide improved fabrics
safety when pretreating fabrics with peroxygen bleach-containing
compositions, especially in those applications where said compositions are
left into contact with said fabrics during prolonged periods of time, before
washing said fabrics.
When pretreating fabrics with compositions comprising a peroxygen bleach
like hydrogen peroxide, it has been found that the presence of metal ions
such as copper and/or iron andlor manganese on the surface of fabrics
produces fabric damage resulting in loss of tensile strength of the fabric
fibres. It is speculated that the presence of metal ions such as copper
and/or iron and/or manganese on the surface of the fabrics, especially on
cellulosic fibres, catalyses the radical decomposition of peroxygen bleaches
like hydrogen peroxide. Thus, a radical reaction occurs on the surface of
the fabric with generation of free radicals, which results in tensile strength
loss.
Therefore we have found that it is essential that this surface radical
reaction
be controlled in the pretreatment environment, thereby providing improved
safety to fabrics.
It has now been found that this can be achieved by formulating a peroxygen
bleach-containing composition which comprises a compound for chelating
copper and/or iron andlor manganese. More particularly, it has been found
that the use of a compound for chelating copper andlor iron and/or
manganese, and preferably diethylene triamine yenta methylene
phosphoric acid (DTPMP), hydroxy-ethane diphosphonic acid (HEDP),
ethyleAediamine N,N'-disuccinic acid (EDDS), methyl glycine di-acetic acid
(MGDA), diethylene triamine yenta acetic acid (DTPA), propylene diamine
tetracetic acid (PDTA), 2-hydroxypyridine-N-oxide (NPNO), or
ethylenedinitrilotertrakis (methylenephosphonic acid) N,N,-dioxide, in a
peroxygen bleach-containing composition, considerably reduces the
damage on a fabric pretreated with such a composition.
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An advantage associated to the use of a peroxygen bleach-containing
composition comprising such a compound for chelating copper and/or iron
and/or manganese, in laundry pretreatment application, is that color
damage is also reduced.
A further advantage of the present invention is that excellent laundry
performance on bleachable stains is provided as well as on removing
greasy stains.
Another advantage of the present invention is that the compositions suitable
to be used according to the present invention also provide excellent
performance when used in other applications, apart from laundry pretreater
application, such as in other laundry applications, as a laundry detergent or
laundry additive, or even in hard surface cleaning applications.
In one embodiment of the present invention it has also been found that the
use of a chelating agent like ethylenedinitrilotertrakis (methylenephosphonic
acid) N,N,-dioxide, hydroxy-ethane diphosphonic acid (HEDP) and/or a
chelating agent having two electron-donor groups able to occupy adjacent
co-ordination sites in the metal ions sphere of co-ordination so as to form
complexes with metal ions in which each metal ion is complexed by 3
molecules of chelating agents like 2-hydroxypyridine-N-oxide, allows to
formulate acidic liquid compositions suitable for pretreating fabrics which
exhibit improved chemical stability upon prolonged storage time.
Peroxygen bleach-containing compositions have been extensively
described in the art. EP-A- 629691 discloses emulsions of nonionic
surfactants comprising a silicone compound, and as optional ingredients,
hydrogen peroxide, or a water soluble source thereof, and chelants. The
only chelant disclosed is S,S,-ethylene diamino disuccinic acid (see
examples). Although pretreatment application is disclosed for the
r compositions of EP-A 629691, the use of peroxygen bleach-containing
compositions comprising a compound chelating copper and/or iron and/or
manganese, for pretreating fabrics, whereby the loss of tensile strength in
said fabrics is reduced, is nowhere disclosed.
r
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EP-A- 629690 discloses emulsions of nonionic surfactants comprising a
terephthalate-based polymer, and as optional ingredients, hydrogen peroxide,
or a water soluble source thereof, and chelants. The only chelant disclosed is
S,S, -ethylene diamino disuccinic acid (see examples). Although pretreatment
application is disclosed for the compositions of EP-A 629690, the use of
peroxygen bleach-containing compositions comprising a compound chelating
copper and/or iron and/or manganese, for pretreating fabrics, whereby the
loss of tensile strength in said fabrics is reduced, is nowhere disclosed.
EP-B-209 228 discloses compositions comprising a peroxide source tike
hydrogen peroxide, an amino polyphosphonate chelant and a radical
scavenger. Diethylene triamine penta methylene phosphonic acid is expressly
disclosed. Also EP-13-209 228 discloses that the hydrogen
peroxide-containing compositions may be used as pre-spotters. However,
nowhere it is mentioned that peroxygen bleach-containing compositions
comprising a compound chelating copper and/or iron and/or manganese, for
pretreating fabrics, allow to reduce the loss of tensile strength in said
fabrics.
Summary of the invention
In one aspect of the invention there is provided aprocess of pretreating
soiled
fabrics with a liquid composition comprising a peroxygen bleach, butyl
hydroxy toluene a nonionic surfactant system, an anionic surfactant
comprising an alkyl sulphate and/or an alkyl ethoxylated sulphate, and a
compound chelating copper and/or iron and/or manganese, selected from the
group consisting of ethylene diamine N,N'-disuccinic acid or alkali metal, or
alkaline earth or ammonium or substituted ammonium salts thereof,
diethylene triamine penta acetic acid, methyl glycine di-acetic acid,
diethylene
triamine penta methylene phosphonic acid, hydroxy-ethane diphosphonic
acid, propylene diamine tetraacetic acid, 2-hydroxypyridine-N-oxide, ethylene
dinitrilotertrakis (methylene phosphonic acid) N,N-oxide and mixtures thereof
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5
wherein said nionic surfactant system includes one or more nonionic
surfactants selected from the group consisting of hydrophobic nonionic
surfactants having an HLB up to 9 and having the formula: RO--
(C2H40)~(C3H60)mH, wherein R is a C6 to C22 alkyl chain or a C6 to C2a alkyl
benzene chain and mixtures thereof, and wherein n+m is from 0.5 to 5 and n
is from 0 to 5 and m is from 0 to 5; said process comprising the steps of
applying said composition in its neat form onto the fabric and allowing said
composition to remain in contact with said fabric without leaving said
composition to dry onto said fabric, before said fabric is washed.
In another aspect of the invention there is provided a liquid detergent
composition comprising a peroxygen bleach, butyl hydroxy toluene a nonionic
surfactant system, an anionic surfactant comprising an alkyl sulphate or an
alkyl ethoxylated sulphate, and a compound chelating copper and/or iron
and/or manganese selected from the group consisting of ethylene diamine
N,N'disuccinic acid or alkali metal or alkaline earth, ammonium or ammonium
substituted salts thereof, diethylene triamine penta acetic acid, methyl
glycine
di-acetic acid, diethylene triamine penta methylene phosphoric acid, hydroxy-
ethane diphsophonic acid, propylene diamine tetraacetic acid, 2-
hydroxypyridine-N-oxide, ethylene dinitrilotertrakis (methylene phosphoric
acid) N,N-oxide and mixtures thereof, wherein said nonionic surfactant
system includes one or more nonionic surfactants selected from the group
consisting of hydrophobic nonionic surfactants having an HLB up to 9 and
having the formula: RO--(C2H40)~(C3H60)mH, wherein R is a C6 to C22 alkyl
chain or a C6 to C28 alkyl benzene chain and mixtures thereof, and wherein
n+m is from 0.5 to 5 and n is from 0 to 5 and m is from 0 to 5.
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6
Detailed description of the invention
In its broadest aspect, the present invention encompasses the use of a
liquid composition comprising a peroxygen bleach and a compound
chelating copper and/or iron and/or manganese, for pretreating a soiled
fabric before said fabric is washed, whereby the loss of tensile strength in
said fabric is reduced.
The present invention is based on the fmding that, fabric damage resulting
in tensile strength loss is reduced, when compositions comprising a
peroxygen bleach and a compound chelating copper and/or iron and/or
manganese according to the present invention are used to pretreat soiled
fabrics, as compared to the use of the same compositions but without any '
compound chelating copper and/or iron and/or manganese, to pretreat said
fabrics. '
By "to pretreat soiled fabrics" it is to be understood that the liquid
composition is applied in its neat form onto the soiled fabric and left to act
onto said fabric before said fabric is washed, as described herein after, in
the process of pretreating soiled fabrics according to the present invention.
In other words, the use of a peroxygen bleach-containing composition
comprising a compound chelating copper and/or iron and/or manganese
according to the present invention allows to considerably reduce the tensile
strength loss caused by the presence of copper and/or iron and/or
manganese on the fabric surface, even if said composition is left onto the
fabric to be pretreated upon a prolonged period of time before washing said
fabric, e.g. about 24 hours, and even if said fabric is contaminated by high
levels of copper and/or iron and/or manganese.
The tensile strength loss of a fabric may be measured by employing the
Tensile Strength method, as can be seen in the examples herein after. This
method consists in measuring the tensile strength of a given fabric by
stretching said fabric until it breaks. The force, expressed in Kg, necessary
to break the fabric is the "Ultimate Tensile Stress" and may be measured
with "The Stress-Strain INSTRONT"" Machine". By "tensile strength loss" it is
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to be understood the difference when comparing the tensile strength of a
fabric taken as a reference, i.e. a fabric which has not been pretreated, and
the tensile strength of the same fabric after having been pretreated
according to the present invention. A tensile strength loss of zero means
that no fabric damage is observed.
An advantage associated to the present invention is that the color damage
is also reduced. Indeed, the color change or/and decoloration observed
when pretreating soiled colored fabrics with a peroxygen bleach-containing
composition comprising a compound chelating copper and/or iron and/or
manganese according to the present invention, is reduced, as compared to
the color change and/or decoloration observed when using the same
composition but without any such compound for chelating copper and/or
iron and/or manganese, this even if said composition is left onto the fabrics
upon prolonged periods of time before washing said fabrics. Accordingly,
the present invention also, encompasses the use of a liquid composition
comprising a peroxygen bleach and a compound chelating copper and/or
iron and/or manganese for pretreating a soiled colored fabric before said
fabric is washed, whereby the color damage of said fabric is reduced.
Also fabric tensile strength loss reduction and/or fabric color damage
reduction are obtained with liquid compositions comprising a peroxygen
bleach and a compound chelating copper and/or iron and/or manganese
without compromising on the bleaching performance nor on the stain
removal performance delivered by said compositions.
The present invention further encompasses a process of pretreating soiled
fabrics with a liquid composition comprising a peroxygen bleach and a
compound chelating copper and/or iron and/or manganese, said process
comprises the steps of applying said composition in its neat form onto the
fabric and allowing said composition to remain in contact with said fabric
without leaving said composition to dry onto said fabric, before said fabric
is
washed. Said composition may remain in contact with said fabric, typically
for a period of 1 minute to 24 hours, preferably 1 minute to 1 hour and more
preferably 5 minutes to 30 minutes. Optionally, when the fabric is soiled with
encrusted stains/soils which otherwise would be relatively difficult to
remove, the compositions according to the present invention may be rubbed
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and/or brushed more or less intensively, for example, by means of a sponge
or a brush or simply by rubbing two pieces of fabric each against the other.
By "washing" it is to be understood herein to simply rinse the fabrics with
water, or the fabrics may be washed with conventional compositions
comprising at least one surface active agent, this by means of a washing
Y
machine or simply by hand.
By "in its neat form" it is to be understood that the compositions described
herein are applied onto the fabrics to be pretreated without undergoing any
dilution, i.e. they are applied as described herein.
According to the process of pretreating soiled fabrics of the present
invention, the liquid compositions used in said process should not be left to
dry onto the fabrics. Indeed, it has been found that water evaporation
contributes to increase the concentration of free radicals onto the surface of
the fabrics and, consequently, the rate of chain reaction. It is also
speculated that an auto-oxidation reaction occurs upon evaporation of water
when the liquid compositions are left to dry onto the fabrics. Said reaction
of auto-oxidation generates peroxy-radicals which may contribute to the
degradation of cellulose. Thus, not leaving the liquid compositions, as
described herein, to dry onto the fabric, in the process of pretreating soiled
fabrics according to the present invention, contributes to the benefits
according to the present invention, i. e. to reduce the tensile strength loss
when pretreating fabrics with liquid peroxygen bleach-containing
compositions.
As an essential element the compositions suitable to be used according to
the present invention comprise a peroxygen bleach. Preferred peroxygen
bleach is hydrogen peroxide, or a water soluble source thereof, or mixtures
thereof. Hydrogen peroxide is most preferred to be used in the compositions
according to the present invention. As used herein a hydrogen peroxide
source refers to any compound which produces hydrogen peroxide when
said compound is in contact with water.
Suitable water-soluble sources of hydrogen peroxide for use herein include
percarbonates, persilicate, persulphate such as monopersulfate, perborates
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and peroxyacids such as diperoxydodecandioic acid (DPDA), magnesium
perphthalatic acid and mixtures thereof.
Typically, the compositions suitable to be used herein comprise from 0.5%
to 20% by weight of the total composition of said peroxygen bleach,
' preferably from 2% to 15% and most preferably from 3% to 10%. Indeed,
the presence of peroxygen bleach, preferably hydrogen peroxide provides
strong cleaning benefits which are particularly noticeable in laundry
applications.
As a second essential ingredient, the compositions suitable to be used
according to the present invention comprise a compound chelating copper
and/or iron and/or manganese. Typically, the compositions suitable to be
used herein comprise from 0.005% to 2% by weight of the total composition
of said compound chelating copper and/or iron and/or manganese, or
mixtures thereof, preferably from 0.01 % to 1 % and most preferably from
0.01 % to 0.5%.
Said compounds chelating copper and/or iron and/or manganese may be
any compound capable of binding copper and/or iron and/or manganese.
Such compounds chelating copper and/or iron and/or manganese can be
selected from the group comprising phosphonate chelants, amino
carboxylate chelants, polyfunctionally-substituted aromatic chelating agents
or polycarboxylic acids of pyridine and the like, or mixtures thereof.
Such phosphonate chelants may include ethydronic acid, hydroxy-ethane
diphosphonic acid (HEDP) and ethylenedinitrilotertrakis
(methylenephosphonic acid) N, N-oxide as well as amino phosphonate
compounds such as amino alkylene poly (alkylene phosphonate), alkali
metal ethane 1-hydroxy diphosphonates, nitrilo trimethylene phosphonates,
ethylene diamine tetra methyiene phosphonates, and diethylene triamine
penta methylene phosphonates. 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. Phosphonate chelants are commercially
available from Monsanto under the trade name DEQUEST~~ Preferred
phosphonate chelants to be used herein are diethylene triamine yenta
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methylene phosphonates, hydroxy-ethane diphosphonic acid (HEDP) and
ethylenedinitrilotertrakis (methylenephosphonic acid) N,N-oxide.
Hydroxy-ethane diphosphonic acid and ethylenedinitrilotertrakis
(methylenephosphonic acid) N,N-oxide have been found to be particularly
resistant to protonation and oxidation. Thus hydroxy-ethane diphosphonic
acid and ethylenedinitrilotertrakis (methylenephosphonic acid) N,N-oxide
are particularly suitable for application in acidic liquid compositions as a
compound for chelating copper and/or iron arid/or manganese according to
the present invention whereby fabrics safety is improved. Indeed, hydroxy-
ethane diphosphonic acid and/or ethylenedinitrilotertrakis
(methylenephosphonic acid) N,N-oxide allow to formulate liquid acidic
peroxygen bleach-containing compositions with improved chemical stability
as compared to the same compositions without said chelating agent, or as
compared to the same compositions but with another chelating agent, e.g.
diethylene triamine yenta methylene phosphonic acid, instead of said
chelating agent. Thus another aspect of the present invention is the use of
hydroxy-ethane diphosphonic acid and/or ethylenedinitrilotertrakis
(methylenephosphonic acid) N,N-oxide, in an acidic liquid peroxygen
bleach-containing composition, whereby the chemical stability of said
composition is improved, i.e. the rate of decomposition of said bleach is
reduced upon prolonged time of storage of said composition.
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.
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,
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commercially available under the tradename ssEDDS~ from Palmer
Research Laboratories.
Such amino carboxylates useful as compounds chelating copper and/or iron
and/or manganese include ethylene diamine tetra acetates, diethylene
triamine pentaacetates, diethylene triamine pentoacetate (DTPA), N-
hydroxyethylethylenediamine triacetates, nitrilotri-acetates, ethylenediamine
tetraproprionates, triethylenetetraaminehexa-acetates, ethanoldiglycines,
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 to be used herein
are diethylene triamine penta acetic acid (DTPA), 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).
Suitable polycarboxylic acids of pyridine to be used herein include
dipicolinic acid. Preferred herein dipicolinic acid is used in mixture with
another compound for chelating copper and/or iron and/or manganese
according to the present invention. Indeed, dipicolinic acid is preferably
added on top of other chelants herein in a liquid composition according to
the present invention to improve the chemical stability of said composition.
Other chelating agents suitable to be used herein as compounds chelating
copper and/or iron andlor manganese include chelating agents having two
electron-donor groups able to occupy adjacent co-ordination sites in the
metal ions sphere of co-ordination so as to form complexes with metal ions
in which each metal ion is complexed by 3 molecules of chelating agents
(3:1 chelating agent: metal ion stoichiometrie). In other words, said
chelating
agents occupy the co-ordination sphere of the metal ion, making it thereby
catalytically inactive. Said chelating agents have been found to be
particularly resistant to protonation and/or oxidation. Said chelating agents
are thus particularly suitable for application in acidic liquid compositions
as
a compound for chelating copper and/or iron and/or manganese according
- to the present invention whereby fabrics safety is improved. Indeed, said
chelating agents having two electron-donor groups able to occupy adjacent
co-ordination sites in the metal ions sphere of co-ordination allow to
formulate acidic peroxygen bleach-containing compositions with improved
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chemical stability as compared to the same compositions without any such
chelating agents or as compared to the same compositions with another
chelating agent, e.g. diethylene triamine penta methylene phosphonic acid,
instead of said chelating agents. Thus, another aspect of the present
invention is the use of chelating agents having two electron-donor groups
able to occupy adjacent co-ordination sites in the metal ions sphere of co-
ordination so as to form complexes with metal ions in which each metal ion
is complexed by 3 molecules of said chelating agents, in an acidic liquid
peroxygen bleach-containing composition, whereby the chemical stability of
said composition is improved, i.e. the rate of decomposition of said bleach
is reduced upon prolonged time of storage of said composition.
Said chelating agents having two electron-donor groups able to occupy
adjacent co-ordination sites in the metal ions sphere of co-ordination
include chelating agents having at least an ionised carboxylate directly
adjacent to one of the following groups: an unionised carboxylate, a
hydroxyl group, an amino group or an N-oxide group. Particularly suitable to
be used herein are malonic acid, 2-hydroxypyridine-N-oxide, or mixtures
thereof.
2-hydroxy-pyridine-N-oxide is, for instance, commercially available from
Pyrion Chemie (Germany) under the trade name 2-hydroxy-pyridine-N-
oxide.
According to the present invention, liquid compositions comprising a
peroxygen bleach and, as a compound chelating copper and/or iron and/or
manganese, propylene diamine tetracetic acid (PDTA), methyl glycine di-
acetic acid (MGDA), diethylene triamine penta methylene phosphonate
(DTPMP), hydroxy-ethane diphosphonic acid (HEDP), ethylenediamine
N,N'- disuccinic acid (EDDS), 2-hydroxypyridine-N-oxide (HPNO), and/or
ethylenedinitrilotertrakis (methylenephosphonic acid) N,N-oxide, provide
virtually no tensile strength loss in fabrics pretreated therewith, i.e. the
fabric resistance is not reduced, even upon prolonged contact periods of
said compositions onto said fabrics, e.g. 24 hours.
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The present invention accordingly further encompasses liquid compositions
comprising a peroxygen bleach, as described herein before and, as the
compound chelating copper and/or iron and/or' manganese, propylene
diamine tetracetic acid (PDTA), methyl glycine di-acetic acid (MGDA), 2-
hydroxypyridine-N-oxide, ethylenedinitrilotertrakis (methylenephosphonic
acid) N,N-oxide, hydroxy-ethane diphosphonic acid, or mixtures thereof.
The following description of the compositions relates to the compositions of
the present invention claimed per se, to the compositions used according to
the present invention for pretreating soiled fabrics and to the compositions
applied onto the fabrics according to the process of pretreating soiled
fabrics of the present invention.
The compositions according to the present invention are aqueous liquid
cleaning compositions. Said aqueous compositions have a pH as is of from
1 to 9, preferably from 2 to 6 and more preferably from 3 to 5. The pH of
the compositions can be adjusted by using organic or inorganic acids, or
alkalinising agents.
The compositions according to the present invention may further comprise a
variety of optional ingredients such as radical scavengers, surfactants,
builders, stabilisers, other chelants, soil suspenders, dye transfer agents,
solvents, brighteners, perfumes, antioxidants, foam suppressors and dyes.
A preferred optional ingredient of the compositions according to the present
invention is a radical scavenger or mixtures thereof. Suitable radical
scavengers for use herein include the well-known substituted mono and di
hydroxy benzenes and their analogs, alkyl and aryl carboxylates and
mixtures thereof. Preferred radical scavengers for use herein include butyl
hydroxy toluene, 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, commercially available under the trade name Topanol
a CA~ ex ICI, as well as n-propyl-gallate. Radical scavengers when used, are
typically present herein in amounts ranging from 0.001 % to 2% by weight of
the total composition and preferably from 0.001 % to 0.5% by weight.
The compositions according to the present invention may further comprise
any surfactant known to those skilled in the art including nonionic, anionic,
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cationic, zwitterionic, or amphoteric surfactants. The compositions
according to the present invention preferably comprise any of the nonionic
surfactants or mixtures thereof described herein after andlor any of the
anionic surfactants or mixtures thereof described herein after. Typically, the
compositions according to the present invention may comprise up to 50%
by weight of the total composition of a surfactant, or mixtures thereof.
The compositions of the present invention may also comprise a liquid
hydrophobic bleach activator, as a highly preferred optional ingredient. By
bleach activator, it is meant herein a compound which reacts with hydrogen
peroxide to form a peracid. The peracid thus formed constitutes the
activated bleach. By "hydrophobic bleach activator", it is meant herein an
activator which is not substantially and stably miscible with water.
Typically,
such hydrophobic bleach activators have an HLB of below 11. Such
suitable liquid hydrophobic bleach activators typically belong to the class of
esters, amides, imides, or anhydrides. A particular family of bleach
activators of interest was disclosed in EP 624 154, and particularly
preferred in that family is acetyl triethyl citrate (ATC). ATC has the other
advantages that it is environmentally friendly in that it eventually degrades
into citric acid and alcohol. Also, ATC has good hydrolytical stability in the
compositions herein, and it is an efficient bleach activator. Finally, it
provides good building capacity to the compositions. It is also possible to
use mixtures of liquid hydrophobic bleach activators herein. The
compositions herein may comprise up to 20% by weight of the total
composition of said bleach activator or mixtures thereof, preferably from 2%
to 10%, most preferably from 3% to 7%.
When the peroxygen bleach-containing compositions according to the
present invention further comprise a liquid hydrophobic bleach activator it is
highly desired herein for stability purpose to formulate said compositions
either as aqueous emulsions of surfactants which comprise said liquid
hydrophobic bleach activator, or as microemulsions of said liquid
hydrophobic bleach activator in a matrix comprising water, the peroxygen
bleach and a hydrophilic surfactant system comprising an anionic and a
nonionic surfactant.
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In the embodiment of the present invention where the peroxygen bleach-
containing compositions of the present invention further comprise said
bleach activator and are formulated as aqueous emulsions, said peroxygen
- bleach-containing emulsions comprise an emulsifying surfactant system of
at least two different surfactants, i.e. at least a hydrophobic surfactant
"_ having an HLB up to 9 and at least a hydrophilic surfactant having an HLB
above 10 in order to emulsify the liquid hydrophobic bleach activator.
Indeed, said two different surtactants in order to form emulsions which are
stable must have different HLB values (hydrophilic lipophilic balance), and
preferably the difference in value of the HLBs of said two surfactants is at
least 1, preferably at least 3. In other words, by appropriately combining at
least two of said surfactants with different HLBs in water, stable emulsions
will be formed, i.e. emulsions which do not substantially separate into
distinct layers, upon standing for at least two weeks at 50 °C.
The emulsions according to the present invention comprise from 2 % to 50
by weight of the total composition of said hydrophilic and hydrophobic
surfactants, preferably from 5 % to 40 % and more preferably from 8 % to
30%. The emulsions according to the present invention comprise at least
from 0.1 % by weight of the total emulsion of said hydrophobic surfactant, or
mixtures thereof, preferably at least 3 % and more preferably at least 5
and at least from 0.1 % by weight of the total emulsion of said hydrophilic
surfactant, or mixtures thereof, preferably at least 3 %, and more preferably
at least 6 %.
Preferred to be used herein are the hydrophobic nonionic surtactants and
hydrophilic nonionic surfactants. Said hydrophobic nonionic surfactants to
be used herein have an HLB up to 9, preferably below 9, more preferably
below 8 and said hydrophilic surtactants have an HLB above 10, preferably
above 11, more preferably above 12. Indeed, the hydrophobic nonionic
surfactants to be used herein have excellent grease cutting properties, i.e.
they have a solvent effect which contributes to hydrophobic soils removal.
The hydrophobic surfactants act as carrier of the hydrophobic brighteners
onto the fabrics allowing thereby said brighteners to work in close proximity
with the fabrics surface since the beginning of the wash.
Suitable nonionic surtactants for use herein include alkoxylated fatty
alcohols preferably, fatty alcohol ethoxylates and/or propoxylates. Indeed, a
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16
great variety of such alkoxylated fatty alcohols are commercially available
which have very different HLB values (hydrophilic lipophilic balance). The
HLB values of such alkoxylated nonionic surfactants depend essentially on
the chain length of the fatty alcohol, the nature of the alkoxylation and the
degree of alkoxylation. Hydrophilic nonionic surfactants tend to have a high
degree of alkoxylation and a short chain fatty alcohol, while hydrophobic
surfactants tend to have a low degree of alkoxylation and a long chain fatty
alcohol. Surfactants catalogs are available which list a number of
surfactants including nonionics, together with their respective HLB values.
Suitable chemical processes for preparing the nonionic surfactants for use
herein include condensation of corresponding alcohols with alkylene oxide,
in the desired proportions. Such processes are well known to the man
skilled in the art and have been extensively described in the art. As an
alternative, a great variety of alkoxylated alcohols suitable for use herein
is
commercially available from various suppliers.
Preferred hydrophobic nonionic surfactants to be used according to the
present invention are surfactants having an HLB up to 9 and being
according to the formula RO-(C2H40)n(C3Hg0)mH, wherein R is a C6 to
C22 alkyl chain or a Cg to C2g alkyl benzene chain, and wherein n+m is
from 0.5 to 5 and n is from 0 to 5 and m is from 0 to 5 and preferably n+m is
from 0.5 to 4 and, n and m are from 0 to 4. The preferred R chains for use
herein are the Cg to C22 alkyl chains. Accordingly suitable hydrophobic
nonionic surfactants for use herein are Dobanol R 91-2.5 (HLB= 8.1; R is a
mixture of Cg and C11 alkyl chains, n is 2.5 and m is 0), or Lutensol R T03
(HLB=8; R is a mixture of C13 and C15 alkyl chains, n is 3 and m is 0), or
Tergitol R 25L3 (HLB= 7.7; R is in the range of C12 to C15 alkyl chain
length, n is 3 and m is 0), or Dobanol R 23-3 (HLB=8.1; R is a mixture of
C12 and C13 alkyl chains, n is 3 and m is 0), or Dobanol R 23-2 (HLB=
6.2; R is a mixture of C12 and C13 alkyl chains, n is 2 and m is 0), or
mixtures thereof. Preferred herein are Dobanol R 23-3, or Dobanol R 23-
2, Lutensol R T03, or mixtures thereof. These Dobanol R surfactants are
commercially available from SHELL. These Lutensol R surfactants are
commercially available from BASF and these Tergitol R surfactants are
commercially available from UNION CARBIDE. Other suitable hydrophobic
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17
nonionic surtactants to be used herein are non alkoxylated surfactants. An
example is Dobanol R 23 (HLB<3 ).
Preferred hydrophilic nonionic surfactants to be used according to the
present invention are surfactants having an HLB above 10 and being
according to the formula RO-(C2H40)n(C3H60)mH, wherein R is a C6 to
C22 alkyl chain or a Cg to C2g alkyl benzene chain, and wherein n+m is
from 5 to 11 and n is from 0 to 11 and m is from 0 to 11, preferably n+m is
from 6 to 10 and, n and m are from 0 to 10. Throughout this description n
and m refer to the average degree of the ethoxylation/propoxylation. The
preferred R chains for use herein are the Cg to C22 alkyl chains.
Accordingly suitable hydrophilic nonionic surfactants for use herein are
Dobanol R 23-6.5 (HLB=11.9 ; R is a mixture of C12 and C13 alkyl chains,
n is 6.5 and m is 0), or Dobanol R 25-7 (HLB=12 ; R is a mixture of C12 to
C15 alkyl chains, n is 7 and m is 0), or Dobanol R 45-7 (HLB=11.6 ; R is a
mixture of C14 and C15 alkyl chains, n is 7 and m is 0), or Dobanol R 91-5
(HLB=11.6 ; R is a mixture of Cg to C11 alkyl chains, n is 5 and m is 0), or
Dobanol R 91-6 (HLB=12.5 ; R is a mixture of Cg to C11 alkyl chains, n is 6
and m is 0), or Dobanol R 91-8 (HLB=13.7; R is a mixture of Cg to C11 alkyl
chains, n is 8 and m is 0), or Dobanol R 91-10 (HLB= 14.2 ; R is a mixture
of Cg to C11 alkyl chains, n is 10 and m is 0), or mixtures thereof.
Preferred herein are Dobanol R 91-10, or Dobanol R 45-7, Dobanol R 23-
6.5, or mixtures thereof . These Dobanol R surfactants are commercially
available from SHELL. Apart from the hydrophilic nonionic surfactants other
hydrophilic surfactants may further be used in the emulsions of the present
invention such as anionic surfactants described herein after.
The emulsions according to the present invention may further comprise
other surfactants which should however not significantly alter the Weighted
average HLB value of the overall emulsion.
In a particularly preferred embodiment of the emulsions of the present
invention, wherein the emulsions comprise Acetyl triethyl citrate as the
bleach activator, an adequate nonionic surfactant system would comprise a
hydrophobic nonionic surtactant with for instance an HLB of 6, such as a
Dobanol R 23-2 and a hydrophilic nonionic surtactant with for instance an
HLB of 15, such as a Dobanol R 91-10. Other suitable nonionic surtactant
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18
systems comprise for example a Dobanol R 23-6.5 (HLB about 12) and a
Dobanol R 23 (HLB below 6) or a Dobanol R 45-7 (HLB=11.6) and Lutensol
R T03 (HLB=8).
In the embodiment of the present invention where the peroxygen bleach-
containing compositions of the present invention comprise said bleach
activator and are formulated as microemulsions, said peroxygen bleach-
containing microemulsions according to the present invention comprise a
hydrophilic surfactant system comprising an anionic surfactant and a
nonionic surfactant. A key factor in order to stably incorporate the
hydrophobic activator is that at least one of said surfactants must have a
different HLB value to that of the hydrophobic activator. Indeed, if all said
surfactants had the same HLB value as that of the hydrophobic activator, a
continuous single. phase might be formed thus lowering the chemical
stability of the bleach/bleach activator system. Preferably, at least one of
said surfactants has an HLB value which differs by at least 1.0 HLB unit,
preferably 2.0 to that of said bleach activator.
Suitable anionic surfactants herein include water soluble salts or acids of
the formula ROS03M wherein R preferably is a C10-C24 hydrocarbyl,
preferably an alkyl or hydroxyalkyl having a C10-C20 alkyl component,
more preferably a C12-C1g 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 C12-16 are
preferred for lower wash temperatures (e.g., below about 50°C) and C16-
18
alkyl chains are preferred for higher wash temperatures (e.g., above about
50°C).
Other suitable anionic surfactants for use herein are water soluble salts or
acids of the formula RO(A)mS03M wherein R is an unsubstituted C10-C24
alkyl or hydroxyalkyl group having a C1p-C24 alkyl component, preferably a
C12-C20 alkyl or hydroxyalkyl, more preferably C12-C1 g alkyl or
hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero,
typically
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19
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 ethoxytated 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 atkanolamines
such as ethylamine, diethylamine, triethylamine, mixtures thereof, and the
like. Exemplary surfactants are C12-C1g alkyl polyethoxylate (1.0) sulfate,
C12-C18E(1.0)M), C12-C1g alkyl polyethoxylate (2.25) sulfate, C12-
C18E(2.25)M), C12-C1 g alkyl polyethoxylate (3.0) sulfate C12-C1 gE(3.0),
and C12-C1 g alkyl polyethoxylate (4.0) sulfate C12-C18E(4.0)M), wherein
M is conveniently selected from sodium and potassium.
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, Cg-C20 linear alkylbenzenesulfonates, Cg-
C22 primary or secondary alkanesulfonates, Cg-C24 olefinsulfonates,
sulfonated polycarboxylic acids prepared by sulfonation of the pyrolyzed
product of alkaline earth metal citrates, e.g., as described in British patent
specification No. 1,082,179, Cg-C24 alkylpolyglycolethersulfates
(containing up to 10 moles of ethylene oxide); alkyl ester sulfonates such as
C14-16 methyl ester sulfonates; acyl glycerol sulfonates, fatty oleyl glycerol
sulfates, alkyl phenol ethylene oxide ether sulfates, paraffin sulfonates,
alkyl phosphates, isethionates such as the acyl isethionates, N-acyl
taurates, alkyl succinamates and sulfosuccinates, monoesters of
sulfosuccinate (especially saturated and unsaturated C12-C1g monoesters)
diesters of sulfosuccinate (especially saturated and unsaturated C6-C14
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(CH2CH20)kCH2C00-M+ wherein R is a C8-
C22 alkyl, k is an integer from 0 to 10, and M is a soluble salt-forming
cation. Resin acids and hydrogenated resin acids are also suitable, such
as rosin, hydrogenated rosin, and. resin acids and hydrogenated resin acids
CA 02213633 2001-05-02
2~
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 8erch).
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
Suitable nonionic surtactants for use in the microemulsions herein include
the hydrophilic nonionic surfactants as defined herein before.
The preferred making of the microemulsions of the present invention which
comprises a liquid hydrophobic bleach activator includes premixing the
surfactants with water and subsequently adding the other ingredients
including hydrogen peroxide and said hydrophobic bleach activator.
Irrespective of this preferred order of addition, it is important that during
the
mixing of the ingredients, the microemulsions be constantly kept under
stirring under relatively high stirring energies, preferably 30 minutes at 750
rpm, most preferably 30 minutes at 1000 rpm.
In the embodiment of the present invention where the compositions are
formulated as microemulsions said compositions are macroscopically
transparent in the absence of opacifiers and dyes. In centrifugation
examination, it was observed that said microemulsions herein showed no
phase separation after 15 minutes at 6000 RPM. Under microscopic
examination, said microemulsions appeared as a dispersion of droplets in a
matrix. The matrix is the hydrophilic matrix described hereinbefore, and the
droplets are constituted by the liquid hydrophobic bleach activator. We
have observed that the particles had a size which is typically around or
below 3 micron diameter.
The compositions suitable to be used according to the present invention
may further comprise a foam suppressor such as 2-alkyl alkanol, or
mixtures thereof, as a highly preferred optional ingredient. Particularly
suitable to be used in the present invention are the 2-alkyl alkanols having
an alkyl chain comprising from 6 to 16 carbon atoms, preferably from 8 to
12 and a terminal hydroxy group, said alkyl chain being substituted in the oc
position by an alkyl chain comprising from 1 to 10 carbon atoms, preferably
from 2 to 8 and more preferably 3 to 6. Such suitable compounds are
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21
commercially available, for instance, in the Isofol~ series such as Isofol~
12 (2-butyl octanol) or Isofol~ 16 (2-hexyl decanol). Typically, the
compositions suitable to be used herein comprise from 0.05 % to 2 % by
weight of the total composition of a 2-alkyl alkanol, or mixtures thereof,
preferably from 0.1 % to 1.5 % and most preferably from 0.1 % to 0.8 %.
Although preferred application of the compositions described herein is
laundry pretreatment, the compositions according to the present invention
may also be used as a laundry detergent or as a laundry detergent booster
as well as a household cleaner in the bathroom or in the kitchen. When
used as hard surface cleaners, such compositions are easy to rinse and
provide good shine characteristics on the cleaned surtaces.
The present invention will be further illustrated by the following examples.
A) Experimental data
The following compositions were made by mixing the listed ingredients in
the listed proportions (weight % unless otherwise specified).
Compositions I II III IV V VI
Alkylsulphate 1.2 1.2 1.2 1.2 1.2 1.2
Dobanol~ 91-10 1.6 1.6 1.6 1.6 1.6 1.6
Dobanol~ 23.3 1.1 1.1 1.1 1.1 1.1 1.1
H202 7.0 7.0 7.0 7.0 7.0 7.0
BHT 0.03 0.03 0.03 0.03 0.03 0.03
Perfume 0.1 0.1 0.1 0.1 0.1 0.1
S,S-EDDS ____ 0.5 ____ ___ ____ ____
DTPMP -__ - 0.5 _--- ___ ___
MGDA ____ ____ ___ 0.5 ___ ____
DTPA ____ ____ ___ ____ 0.5 ___
H E D P ___ ____ ____ ___ ___ 0.
5
Water and minors _____________________up
_________
to
100%-__
_ ________
H2S04 up to pH 4
Tensile strength loss (%) 60 0 0 2 4 0
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22
50 ppm Copper per gram of fabric
Pretreatment 24 hours
S,S EDDS is ethylenediamine -N,N'-disuccinic acid (S,S isomer).
DTPMP is diethylene triamine penta methylene phosphonate marketed by
Monsanto under the trade name DEQUEST~.
MGDA is methyl glycine di-acetic acid.
PDTA is propylene diamine tetracetic acid marketed by BASF under the
trade name Trilon FS~.
Composition I comprises only hydrogen peroxide and is free of compounds
chelating copper and/or iron and/or manganese. Compositions II to VI are
representative of the present invention, they comprise hydrogen peroxide
and a compound chelating copper and/or iron and/or manganese.
The following test was carried out:
A tensile strength test method was carried out with the compositions
mentioned herein above. This test method was carried out on metal-
polluted fabrics.
Cotton ribbons (dimension 12.5 x 5 cm2) having a copper concentration of
50 ppm per gram of cotton were pretreated according to the present
invention. Indeed, the cotton ribbons were pretreated with 2 ml of each of
the liquid compositions mentioned herein before. The compositions were
left in contact with the ribbons for 24 hours, before being rinsed with water.
After that, the damage on the fabrics, i.e. cotton ribbons, was evaluated by
stretching said ribbons until they broke. The force necessary to break the
ribbons, i.e. the Ultimate Tensile Stress, was measured, in wet conditions,
with "The Stress-Strain INSTRON Machine". The lower the force needed to
break said cotton ribbons, the more serious the damage caused on the
fabrics. A good confidence (standard deviation=2-5 Kg) on the results is
obtained using five replicates for each test.
The tensile strength loss mentioned above for the different compositions
tested is expressed in percentage and is obtained by comparing the tensile
strength of a given fabric taken as a reference, i.e. a fabric which has not
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23
PCT/LTS96/022I9
been pretreated, to the tensile strength of the same fabric measured after
said fabric has been pretreated as mentioned herein before.
The above results clearly show the unexpected safety improvement, i.e.
reduction of tensile strength loss, obtained by using liquid compositions
according to the present invention comprising a peroxygen bleach and a
compound chelating copper and/or iron and/or manganese, as compared to
the use of the same compositions but without any compound chelating
copper and/or iron and/or manganese (composition I). Indeed, there is
virtually no tensile strength loss observed when pretreating fabrics with
compositions according to the present invention (see compositions 11 to VI),
this even upon a long contact period, i.e. 24 hours and in presence of a
high concentration of copper on the surface of said fabrics, i.e. 50 ppm per
gram of cotton fabric.
B) Examples
Following compositions were made by mixing the listed ingredients in the
listed proportions (weight % unless otherwise specified).
Compositions , I II III IV V VI VII VIII
H202 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0
Alkylsulphate (1 ) 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2
Dobanol R 91-10 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6
Dobanol R 23-3 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1
BHT 0.03 0.03 0.030.03 --- --- 0.09 0.09
2-ButylOctanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
S, S E D D S 0. -- ___ ___ ___ ___ ___
5
___
PDTA ___ 0.5 ___ ___ __ ___ ___ ___
DTPMP ___ ___ 0.5 ___ 0.18 ___ ___ ___
MGDA ___ ___ ___ 0.5 ___ ___ ___ ___
., HPNO ___ --_
___ ___ ___ 0.1 ___ ___
HEDP ___
___ 0.18 ___
DTPA ___ ___ 0.1
Water and minors (dye) ___ __________________
___
___
___
___
___
___
___
___
___________________________up
to
100%-~-___
H2S04 up to pH 4
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24
S,S EDDS is ethylenediamine -N,N'-disuccinic acid (S,S isomer).
DTPMP is diethylene triamine penta methylene phosphonate marketed by
Monsanto under the trade name DEQUEST~.
MGDA is methyl glycine di-acetic acid.
PDTA is propylene diamine tetracetic acid marketed by BASF under the
trade name Trilon FS~.
HPNO is 2-hydroxy pyridine-N-oxide.
HEDP is hydroxy-ethane diphosphonic acid.
DTPA is diethylene triamine penta acetic acid.
Compositions IX X XI XII XIII
I-1202 7.0 7.0 7.0 4.0 6.0
Alkylsulphate 1.2 1.2 1.2 2.0 ---
(1 )
AES 25-3 --- --- --- --- 12.0
Dobanol R 45-7--- --- --- 6.4 6.0
Dobanol R 91-101.6 1.6 1.6 ~- ---
Dobanol R 23-31.1 1.1 1.1 8.6 ---
Dobanol R 23-6.5--- --- --- ~- 6.0
Activator (ATC)--- --- --- 3.5 3.5
BHT 0.03 0.03 0.030.05 0.05
S, S E D D 0.1 --- --- --- ---
S
PDTA ___ 0.1 ___ ___ ___
DTPMP ___ ___ 0.1 ___ ___
HEDP --- --- --- 0.1 0.1
Dipicolinic 0.05 0.05 0.05--- ---
acid
Water and minors------------------up to ------~-
100%-----
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The compositions in examples I to XIII are according to the present
invention. A pretreatment process was carried out according to the present
invention with compositions I to XIII with virtually no tensile strength loss
of
the fabrics treated, even when leaving the compositions to act onto said
fabrics for 24 hours before washing said fabrics.
a
V
