Technical Field
[0001] The present invention relates to the bleaching of fabrics with a peroxygen bleach-containing
pretreater composition packaged in a spray-type dispenser.
Background
[0002] Treatments of fabrics before they are washed, often referred to as fabric pretreatments
are well known in the art. Indeed, it is known to use peroxygen bleach-containing
compositions in laundry pretreatment applications to boost the removal of bleachable
stains/soils which are otherwise particularly difficult to remove. Such liquid peroxygen-bleach
compositions are directly applied by pouring onto the soiled/stained fabrics, followed
optionally by gentle rubbing to aid the penetration of the detergent into the fabrics.
[0003] However, there are some limitations to the convenience of peroxygen bleach. In particular,
we have observed that peroxygen bleach-containing compositions may damage fabrics
resulting in tensile strength loss and/or color damage when used in pretreatment application,
i.e. when applied directly (neat) onto the fabrics, and left to act onto said fabrics
for prolonged periods of time before washing said fabrics.
[0004] It is thus an object of the present invention to provide improved fabric safety and/or
color safety to fabrics when pretreating said fabrics with peroxygen bleach-containing
compositions.
[0005] We have now found that this object is efficiently met by formulating a liquid composition
comprising a peroxygen bleach and a surfactant, and by applying said composition to
the fabrics to be pretreated by spraying it via a spray-type dispenser. Indeed, it
has now been found that by spraying a liquid composition comprising a peroxygen bleach
and a surfactant, onto the soiled/stained fabrics, before said fabrics are washed,
it is possible to reduce the loss of tensile strength in said fabrics and/or to reduce
the color damage of said fabrics, as compared to applying the same liquid composition
in a form other than spraying it onto the soiled/stained fabrics, for example by simply
pouring said composition onto said fabrics, and as compared to spraying the same liquid
composition but without any surfactant. Preferred compositions to be used according
to the present invention further comprise a bleach activator. Accordingly the present
invention encompasses liquid compositions comprising peroxygen-bleach, a surfactant
and a bleach activator, said compositions being packaged in a spray-type dispenser.
[0006] An advantage of the present invention is that a liquid peroxygen bleach-containing
pretreater composition is easily applied to the soiled/stained fabrics while using
a minimum amount of said composition, as compared to applying said liquid pretreater
composition by directly pouring it onto the soiled fabrics, instead of spraying it
according to the present invention. Indeed, the risk of spillage as well as the tendency
of said liquid pretreater composition to be messy when applied onto soiled fabrics
is reduced when said application is made by using a spray-type dispenser.
[0007] Another advantage of the present invention is that excellent laundry performance
is provided on a broad range of stains and soils including bleachable stains such
as wine, tea, coffee, grass, enzymatic stains such as blood, greasy stains such as
spaghetti sauce, mud/clay-containing soils and the like.
[0008] A further advantage of liquid compositions comprising a peroxygen bleach, a surfactant
and a bleach activator and packaged in a spray-type dispenser according to the present
invention, is that excellent performance is also provided when used in other applications,
apart from laundry pretreater application, such as in other laundry applications,
as a laundry detergent or laundry additive, or carpet cleaning applications.
[0009] Yet another advantage is that liquid compositions packaged in a spray-type dispenser
according to the present invention and comprising a peroxygen bleach, a surfactant
and a bleach activator, especially those being formulated as a microemulsion, exhibit
excellent chemical stability. Also said compositions allow to incorporate significant
amounts of anionic surfactants, if it is desirable to have some of them to perform
better on whiteness and stain removal, in particular on particulate and enzymatic
stains, particularly clay and blood.
[0010] EP-A-209 228 discloses household fabric bleaching compositions which may be used
as "pre-spotters". Said compositions comprise bleach like hydrogen peroxide, nonionic
surfactants, amino polyphosphonate chelants and radical scavengers. No spray application
is disclosed.
[0011] WO 95/16023 discloses the use of two separate liquid compositions, the first of which
contains an acid or neutral composition which comprises a peroxide and the second
of which contains an alkaline composition, said first and second compositions being
stored separately and sprayed from a single unit to a common point/surface to be cleaned.
Surfactants may be present in said first or second liquid composition. No bleach activator
is disclosed. No laundry pretreatment is disclosed.
[0012] GB 2 194 547 discloses laundry pre-spotting compositions comprising mixtures of surfactants
and benzyl alcohol, said compositions are in the form of microemulsions and are suitable
for the treatment of heavily soiled areas of fabrics. Bleaches are mentioned as optional
ingredients, for example hydrogen peroxide may be present in amounts of 0% to 3% by
weight of the total composition. No bleach activator is mentioned. No spray application
is mentioned.
[0013] US 4 648 987 discloses thickened laundry pre-wash compositions for remaining in localised
engagement on selected fabric spots. Said pre-wash composition comprises water, surfactants,
cosurfactants, hydrotropes and thickeners like xanthum gum. The thickened pre-wash
compositions may be suitable for use with different dispensers such as those including
pump or trigger sprayer elements. However, no bleaches are disclosed, let alone hydrogen
peroxide.
[0014] EP-A-629 693 discloses a process of bleaching fabrics which comprises the steps of
applying on at least a portion of said fabrics an effective amount of a liquid or
pasty composition comprising acetyl triethyl citrate, then immersing said fabrics
in an aqueous wash liquor and an effective amount of hydrogen peroxide is provided
either in said liquid composition or in said wash liquor. No spray application is
disclosed.
[0015] Co-pending European Patent Application EP-A-0752469 (relevant for novelty only, pursuant
to Art. 54 (3) and (4) EPC) discloses microemulsions of a hydrophobic liquid bleach
activator in a matrix comprising water, hydrogen peroxide or a water soluble source
thereof, and a hydrophilic surfactant system comprising an anionic and a nonionic
surfactant Laundry pretreatment is disclosed, however no spray application is disclosed.
[0016] J 2099662 discloses a volatile bleaching composition composed of aqueous hydrogen
peroxide solution containing 10% to 90% by weight of methanol and/or ethanol. Another
volatile bleaching composition disclosed therein contains hydrogen peroxide and 1%
to 10% by weight of ethylene glycol ether and/or 0.1% to 1% by weight of silicone
oil (dimethyl polysilane). An industrial process for bleaching textile products by
spraying them with one of the above volatile bleaching compositions containing up
to 10% of hydrogen peroxide, without subsequent rinsing is also claimed. J0299662
does not disclose that by spraying a liquid peroxygen bleach/surfactant-containing
composition onto fabrics to pretreat said fabrics, the loss of tensile strength and/or
color damage in said fabrics are reduced.
Summary of the invention
[0017] The present invention encompasses a process for cleaning fabrics with a liquid composition
comprising a peroxygen bleach and a surfactant, said process comprising the steps
of dispensing said composition from a spray-type dispenser onto at least a portion
of said fabrics, allowing said composition to remain in contact with said fabrics
and then washing said fabrics.
[0018] The present invention also encompasses the use of a liquid composition packaged in
a spray-type dispenser, said composition comprising a peroxygen bleach and a surfactant,
for pretreating a soiled fabric before said fabric is washed, for reducing the loss
of tensile strength in said fabric as well as the use of said liquid composition packaged
in a spray-type dispenser, for pretreating a soiled colored fabric before said colored
fabric is washed, for reducing the color damage in said fabric.
[0019] The present invention further encompasses a liquid composition packaged in a spray-type
dispenser for pretreating fabrics, said composition comprising a peroxygen bleach,
a surfactant and a bleach activator. In the preferred compositions of the present
invention wherein said bleach activator is a hydrophobic liquid bleach activator said
compositions of the present invention are formulated as a microemulsion of said hydrophobic
liquid bleach activator in a matrix comprising water, said peroxygen bleach, and a
hydrophilic surfactant system comprising an anionic and a nonionic surfactant.
Detailed description of the invention
[0020] In its broadest embodiment, the present invention encompasses a process of cleaning
fabrics with a liquid composition comprising a peroxygen bleach and a surfactant,
said process comprising the steps of spraying said composition onto at least a portion
of said fabrics, allowing said composition to remain in contact with said fabrics
and then washing said fabrics. Preferably, said composition (in neat form) is left
to act onto said portion of fabrics for a period of time before the fabrics are washed
in said laundry operation. Preferably, said period of time is in between 1 minute
to 24 hours, more preferably 1 minute to 1 hour, most preferably 1 minute to 30 minutes.
Optionally, when the fabric is soiled with encrusted stains/soils which otherwise
would be relatively difficult to remove, said pretreatment process according to the
present invention may further involve rubbing and/or brushing, for example, by means
of a sponge or a brush or simply by rubbing two pieces of fabric against each other.
[0021] 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 machine or simply by hand.
[0022] In a process of pretreating soiled fabrics by using a spray type dispenser, the sprayed
compositions should preferably 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 sprayed 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 sprayed compositions, as described herein, to dry onto the fabric,
in a process of pretreating soiled fabrics via a spray-type dispenser, contributes
to the benefits according the present invention, i.e. to reduce the tensile strength
loss and/or the color damage of fabrics when pretreating fabrics with liquid peroxygen
bleach-containing compositions.
[0023] Actually, the present invention is based on the finding that the color damage of
some kinds of dyes present on colored fabrics, i.e. the color change and/or decoloration,
is reduced when a liquid composition comprising a peroxygen bleach and a surfactant
is sprayed onto soiled colored fabrics to be pretreated, as compared to the color
damage observed when pretreating soiled colored fabrics by directly applying thereto
the same liquid composition but without a spray-type dispenser for example by simply
pouring it thereto and as compared to spraying the same composition but without any
surfactant. In other words, spraying a liquid composition comprising a peroxygen bleach
and a surfactant onto soiled colored fabrics allows to prevent/reduce the decomposition
(oxidation) of dyes generally present on the surface of colored fabrics (e.g. bleach
sensitive dyes and/or metallized dyes including copper-formazan dyes and/or metal-azo
dyes).
[0024] The color damage of a fabric may be evaluated by measuring the color deviation (DE)
for example by employing the color damage method, as can be seen in the examples hereinafter.
This method consists in measuring the color deviation (DE) with 'The Hunterlab tristimulus
MINISCAN". By "color deviation" it is to be understood the difference when comparing
the color of a fabric taken as a reference, e.g., a fabric which has not been pretreated,
and the color of the same fabric after having been pretreated according to the present
invention. A color deviation on bleach sensitive dye of zero means that no color damage
is observed.
[0025] Thus in one aspect, the present invention encompasses the use of a liquid composition
packaged in a spray-type dispenser, said composition comprising a peroxygen bleach
and a surfactant, for pretreating a soiled colored fabric before said colored fabric
is washed, for reducing the color damage of said colored fabric.
[0026] By "to pretreat a soiled fabric" 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. According to the present invention the liquid composition
is sprayed in its neat form onto the soiled fabric and left to act onto said fabric
before said fabric is washed.
[0027] The present invention is also based on the finding that, fabric damage resulting
in tensile strength loss is reduced, when a liquid composition comprising a peroxygen
bleach and a surfactant is sprayed onto the soiled fabrics to be pretreated, as compared
to pretreating soiled fabrics by directly applying thereto the same liquid composition
but without a spray-type dispenser, for example by simply pouring it thereto and as
compared to spraying the same composition but without any surfactant.
[0028] Thus in another aspect, the present invention further encompasses the use of a liquid
composition packaged in a spray-type dispenser, said composition comprising a peroxygen
bleach and a surfactant, for pretreating a soiled fabric before said fabric is washed,
for reducing the loss of tensile strength in said fabric.
[0029] The tensile strength loss of a fabric may be measured by employing the Tensile Strength
method. 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
INSTRON Machine". By "tensile strength loss" it is to be understood the difference
when comparing the tensile strength of a fabric taken as a reference, e.g., 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.
[0030] Also fabric tensile strength loss reduction and/or color damage reduction are obtained
when spraying liquid peroxygen bleach-containing compositions according to the present
invention onto soiled fabrics to be pretreated, without compromising on the bleaching
performance nor on the stain removal performance.
[0031] Compositions suitable to be used according to the present invention are liquid aqueous
compositions packaged in spray-type dispenser and comprising a peroxygen bleach and
a surfactant.
[0032] Thus, they comprise as an essential ingredient a peroxygen bleach or a mixture thereof.
Preferred peroxygen bleach for use herein are hydrogen peroxide or water-soluble sources
thereof or mixtures thereof. As used herein a hydrogen peroxide source refers to any
compound which produces hydrogen peroxide when said compound is in contact with water.
Apart from hydrogen peroxide, suitable water-soluble sources thereof include perborate,
percarbonate, perbenzoic and alkylperbenzoic acids, persilicate and persulfate salts
and the like. Most convenient for use herein is hydrogen peroxide. The compositions
of the present invention should comprise from 0.5% to 20% by weight of the total composition,
preferably from 2% to 15%, most preferably from 3% to 10% of hydrogen peroxide or
a water-soluble source thereof or mixture thereof.
[0033] The compositions according to the present invention comprise as an essential ingredient
a surfactant. The presence of said surfactants in the liquid peroxygen-bleach containing
compositions of the present invention contributes to the benefits obtained according
to the present invention, i.e. reduced loss of tensile strengh and/or reduced color
damage in the pretreated fabrics. The presence of said surfactants in the liquid peroxygen-bleach
containing compositions of the present invention further allows to provide good cleaning
performance on different types of stains including bleachable stains like tea, grass,
enzymatic stains like blood, greasy stains like barbecue sauce, spaghetti sauce, bacon
grease and the like, when pretreating fabrics according to the present invention.
All types of surfactants may be used in the present invention including nonionic,
anionic, cationic, amphoteric or zwitterionic surfactants. It is also possible to
use mixtures of such surfactants without departing from the spirit of the present
invention.
[0034] Suitable nonionic surfactants to be used herein are alkoxylated fatty alcohol nonionic
surfactants which can be readily made by condensation processes which are well known
in the art. Indeed, a great variety of such alkoxylated fatty alcohols are commercially
available which have very different HLB values. The HLB values of such alkoxylated
nonionic surfactants depend essentially on the chain length of the fatty alcohol,
the nature of the alkoxylation and the degree of alkoxylation. Hydrophilic nonionic
surfactants tend to have a high degree of alkoxylation and a short chain fatty alcohol,
while hydrophobic surfactants tend to have a low degree of alkoxylation and a long
chain fatty alcohol. Surfactants catalogues are available which list a number of surfactants
including nonionics, together with their respective HLB values.
[0035] Accordingly, preferred alkoxylated alcohols for use herein are nonionic surfactants
according to the formula RO(E)e(P)pH where R is a hydrocarbon chain of from 2 to 24
carbon atoms, E is ethylene oxide and P is propylene oxide, and e and p which represent
the average degree of, respectively ethoxylation and propoxylation, are of from 0
to 24. The hydrophobic moiety of the nonionic compound can be a primary or secondary,
straight or branched alcohol having from 8 to 24 carbon atoms. Preferred nonionic
surfactants for use in the compositions according to the invention are the condensation
products of ethylene oxide with alcohols having a straight alkyl chain, having from
6 to 22 carbon atoms, wherein the degree of ethoxylation is from 1 to 15, preferably
from 5 to 12. Such suitable nonionic surfactants are commercially available from Shell,
for instance, under the trade name Dobanol ® or from Shell under the trade name Lutensol
®. These nonionics are preferred because they have been found to allow the formulation
of a stable product without requiring the addition of stabilisers or hydrotopes. When
using other nonionics, it may be necessary to add hydrotopes such as cumene sulphonate
or solvents such as butyldiglycolether.
[0036] Suitable anionic surfactants 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).
[0037] 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 alky 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.
[0038] 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
9-C
20 linear alkylbenzenesulfonates, C
8-C
22 primary or secondary alkanesulfonates, 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), acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfates
of alkylpolyglucoside (the nonionic nonsulfated compounds being described below),
branched primary alkyl sulfates, alkyl polyethoxy carboxylates such as those of the
formula RO(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
[0039] Preferred anionic surfactants for use in the compositions herein are the alkyl benzene
sulfonates, alkyl sulfates, alkyl alkoxylated sulfates, and mixtures thereof. Anionic
surfactants provide improved cleaning performance. In the preferred compositions herein
those being in the form of microemulsions and comprising both hydrophobic nonionic
surfactants and anionic surfactants, said anionic surfactants which are hydrophilic
compounds act together with said hydrophobic surfactants such as to counterbalance
the negative effect of hydrophobic surfactants. Said anionic surfactants act as wetting
agent, i.e. in a laundry application they wet the stains on the fabrics, especially
on hydrophilic fabrics, and help hydrogen peroxide to perform its bleaching action
thereby contributing to improved laundry performance on bleachable stains.
[0040] Suitable cationic surfactants to be used herein include derivatives of quaternary
ammonium, phosphonium, imidazolium and sulfonium compounds. Preferred cationic surfactants
for use herein are according to the formula R
1R
2R
3R
4N
+ X
-, wherein X is a counteranion, R
1 is a C
8-C
20 hydrocarbon chain and R
2, R
3 and R
4 are independently selected from H or C
1-C
4 hydrocarbon chains. In a preferred embodiment of the present invention, R
1 is a C
12-C
18 hydrocarbon chain, most preferably C
14, C
16 or C
18, and R
2, R
3 and R
4 are all three methyl, and X is halogen, preferably bromide or chloride, most preferably
bromide. Examples of cationic surfactants are stearyl trimethyl ammonium bromide (STAB),
cetyl trimethyl ammonium bromide (CTAB) and myristyl trimethyl ammonium bromide (MTAB).
[0041] Suitable zwitterionic surfactants contain both cationic and anionic hydrophilic groups
on the same molecule at a relatively wide range of pH's. The typical cationic group
is a quaternary ammonium group, although other positively charged groups like phosphonium,
imidazolium and sulfonium groups can be used. 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 some preferred zwitterionic surfactants
is
R
1-N
+(R
2)(R
3)R
4X
-
wherein R
1 is a hydrophobic group; R
2 and R
3 are each C
1-C
4 alkyl, hydroxy alkyl or other substituted alkyl group which can also be joined to
form ring structures with the N; 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 4 carbon atoms;
and X is the hydrophilic group which is preferably a carboxylate or sulfonate group.
Preferred hydrophobic groups R
1 are alkyl groups containing from 8 to 22, preferably less than 18, more preferably
less than 16 carbon atoms. The hydrophobic group can contain unsaturation and/or substituents
and/or linking groups such as aryl groups, amido groups, ester groups and the like.
In general, the simple alkyl groups are preferred for cost and stability reasons.
[0042] Other specific zwitterionic surfactants have the generic formulas:
R
1-C(O)-N(R
2)-(C(R
3)
2)
n-N(R
2)
2(+)-(C(R
3)
2)
n-SO
3(-)
or
R
1-C(O)-N(R
2)-(C(R
3)
2)
n-N(R
2)
2(+)-(C(R
3)
2)
n-COO
(-)
wherein each R
1 is a hydrocarbon, e.g. an alkyl group containing from 8 up to 20, preferably up to
18, more preferably up to 16 carbon atoms, each R
2 is either a hydrogen (when attached to the amido nitrogen), short chain alkyl or
substituted alkyl containing from one to 4 carbon atoms, preferably groups selected
from the group consisting of methyl, ethyl, propyl, hydroxy substituted ethyl or propyl
and mixtures thereof, preferably methyl, each R
3 is selected from the group consisting of hydrogen and hydroxy groups and each n is
a number from 1 to 4, preferably from 2 to 3, more preferably 3, with no more than
one hydroxy group in any (C(R
3)
2) moiety. The R
1 groups can be branched and/or unsaturated. The R
2 groups can also be connected to form ring structures. A surfactant of this type is
a C
10-C
14 fatty acylamidopropylene(hydroxypropylene)sulfobetaine that is available from the
Sheer Company under the trade name "Varian CAS sulfobetaine"®.
[0043] Suitable amphoteric surfactants are surfactants which are similar to the zwitterionic
surfactants but without the quaternary group. However, they contain an amine group
that is protonated at the low pH of the composition to form a cationic group and they
may also possess an anionic group at these pHs.
[0044] Other suitable amphoteric surfactants include amine oxides having the following formula
R
1R
2R
3NO wherein each of R1, R2 and R3 is independently a substituted or unsubstituted,
linear or branched alkyl groups of from 1 to 30 carbon atoms, preferably of from 6
to 30 carbon atoms, more preferably of from 10 to 20 carbon atoms and most preferably
of from 12 to 18 carbon atoms. It has been observed that in pretreatment of fabrics
according to the present invention, the presence of said amine oxide further improves
the cleaning performance on particulate and/or greasy stains. Suitable amine oxides
for use herein are preferably compatible with peroxygen bleaches.
[0045] Preferably the compositions according to the present invention comprise up to 40%
by weight of the total composition of a surfactant or mixtures thereof, more preferably
from 0.05% to 30%, more preferably from 1% to 20% and most preferably from 2% to 15%.
[0046] The composition according to the present invention as an optional but highly preferred
ingredient further comprises a bleach activator. 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. For the purpose of the present invention,
it is preferred that the bleach activator be hydrophobic in order to ensure that it
is partitioned from the hydrophilic bleach, thus avoiding premature reaction between
both compounds. Accordingly, 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.
Examples of suitable compounds of this type are disclosed in British Patent GB 1 586
769 and GB 2 143 231 and a method for their formation into a prilled form is described
in European Published Patent Application EP-A-62 523. Suitable examples of such compounds
to be used herein are tetracetyl ethylene diamine (TAED), sodium 3,5,5 trimethyl hexanoyloxybenzene
sulphonate, diperoxy dodecanoic acid as described for instance in US 4 818 425 and
nonylamide of peroxyadipic acid as described for instance in US 4 259 201 and n-nonanoyloxybenzenesulphonate
(NOBS). Also suitable are N-acyl caprolactam selected from the group consisting of
substituted or unsubstituted benzoyl caprolactam, octanoyl caprolactam, nonanoyl caprolactam,
hexanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam, formyl caprolactam,
acetyl caprolactam, propanoyl caprolactam, butanoyl caprolactam pentanoyl caprolactam.
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). Acetyl
triethyl citrate has the advantage that it is environmentally friendly in that it
eventually degrades into citric acid and alcohol. Also, Acetyl triethyl citrate has
good hydrolytical stability in the compositions herein, it is an efficient bleach
activator and it provides good building capacity to the compositions. Such bleach
activators like Acetyl triethyl citrate because of their hydrophobicity tend to affine
onto the surface of fabrics and/or stains where they have been applied during the
pretreatment operation instead of dissolving in the aqueous washing solution in which
the fabrics are washed, thus providing surface bleaching instead of solution bleaching,
i.e. the perhydrolysis of the acetyl triethyl citrate into peracetic acid occurs on
the surface of the fabrics and/or stains instead of in the washing solution, increasing
the overall efficiency of the bleaching process. Thus the affinity between the bleach
activator and the fabric, especially the soiled portions thereof is maximised. This
effect is favoured when synthetic fabrics are pretreated, as synthetic fabrics have
a hydrophobic character. Furthermore acetyl triethyl citrate also acts as a substantially
water-insoluble solvent which dissolves the stains, thereby preparing and easing the
subsequent cleaning of the fabrics in the subsequent step where said fabrics are immersed
in the washing solution.
[0047] Accordingly, the compositions herein comprise up to 20% by weight of the total composition
of said bleach activator or mixtures thereof, preferably from 1% to 10%, most preferably
from 2% to 7%.
[0048] The compositions of the present invention comprising a bleach activator, in particular
a liquid hydrophobic bleach activator, on top of said peroxygen bleach are preferably
formulated so as to hold said bleach activator separated from said peroxygen bleach.
This can be achieved by formulating said compositions as a emulsion or a microemulsion,
exhibiting thereby excellent chemical stability. Accordingly, the compositions of
the present invention are preferably formulated as a microemulsion of said hydrophobic
liquid bleach activator in a matrix comprising water, said peroxygen bleach and a
hydrophilic surfactant system comprising an anionic and a nonionic surfactant.
[0049] Accordingly the preferred compositions herein comprise a hydrophilic surfactant system
comprising an anionic surfactant and a nonionic surfactant. A key factor in order
to stably incorporate the hydrophobic activator in said microemulsion is that at least
one of said surfactants must have a significantly 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.
[0050] The preferred making of the compositions of the present invention being formulated
as microemulsions includes premixing the surfactants with water and subsequently adding
the other ingredients including hydrogen peroxide. Eventually the hydrophobic bleach
activator is incorporated. Irrespective of this preferred order of addition, it is
important that during the mixing of the ingredients, the composition be constantly
kept under stirring under relatively high stirring energies, preferably 30 minutes
at 750 rpm, most preferably 30 minutes at 1000 rpm.
[0051] The preferred compositions of the present invention being formulated as microemulsions
can further be characterised by the fact that they are macroscopically transparent
in the absence of opacifiers and dyes, and said compositions can further be characterised
by microscopical examination and centrifugation. In centrifugation, it was observed
that said compositions herein showed no phase separation after 15 minutes at 6000
RPM. Under the microscope, said compositions 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
[0052] As an optional but preferred feature, the compositions herein should be formulated
in the acidic pH range, preferably between 2 and 6, more preferably between 3 and
5.
[0053] The compositions of the present invention are aqueous. Accordingly they comprise
preferably from 10% to 95% by weight of the total composition of water, more preferably
from 20% to 80% and most preferably from 40% to 75%.
[0054] As a further optional ingredient, the compositions herein can comprise up to 5%,
preferably from 0.5% to 4% by weight of the total composition of an alcohol according
to the formula HO - CR'R" - OH, wherein R' and R" are independently H or a C
2-C
10 hydrocarbon chain and/or cycle, or mixtures thereof. In a preferred embodiment according
the present invention, the compositions herein can comprise from 1% to 10% by weight
of the total composition, preferably from 2% to 4% of an alcohol according to the
above formula. Preferred alcohol according to that formula is propanediol. Indeed,
we have observed that these alcohols in general and propanediol in particular also
improve the chemical stability of compositions comprising a peroxygen bleach and a
bleach activator, i.e. lower the decomposition of the bleach and the bleach activator.
In addition, said alcohols lower the surface tension of the compositions herein, thus
preventing superficial film or gel formation. Thus said alcohols improve the aesthetics
of the compositions herein. It is believed that the chemical stabilising effect of
said alcohols is twofold. Firstly they may work as radical scavengers and secondly
they may interact with the hydrogen peroxide preventing or limiting hydrolysis, therefore
reducing the rate of peroxide decomposition.
[0055] As a further optional ingredient, the compositions herein can comprise viscosity
regulating compounds including alcohols according to the following formula or mixtures
thereof:

wherein n is an integer between 0 and 10, wherein R, R', R", R"' and R
iv may be H or C1-C10 linear or branched alkyl chains, or C1-C10 linear or branched
alkenyl or alkinyl chains. Preferred alcohol according to that formula Is benzyl alcohol.
Indeed, we have observed that such compounds are particularly advantageous when it
is desired to formulate compositions according to the present invention at low viscosity,
i.e. liquid compositions having a viscosity of from 5 cps to 2000 cps, preferably
of from 10 cps to 1000 cps when measured with Brookfield spindle 3 at rate 50 rpm
at 20°C.
[0056] Accordingly, the compositions of the present invention comprise up to 20% by weight
of the total composition, preferably from 0.1% to 10%, more preferably from 0.5% to
5% of alcohols having the above formula or mixtures thereof.
[0057] As a further optional ingredient, the liquid compositions of the present invention
may comprise a chelating agent or mixtures thereof. Chelating agents suitable to be
used herein include chelating agents selected from the group of phosphonate chelating
agents, amino carboxylate chelating agents, polyfunctionally-substituted aromatic
chelating agents, polyamine chelating agents and further chelating agents like glycine,
salicylic acid, aspartic acid, glutamic acid, malonic acid, or mixtures thereof.
[0058] Suitable phosphonate chelating agents to be used herein may include ethydronic acid
as well as amino phosphonate compounds, including amino alkylene poly (alkylene phosphonate),
alkali metal ethane 1-hydroxy diphosphonates, nitrilo trimethylene phosphonates, ethylene
diamine tetra methylene 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. Preferred phosphonate
chelating agents to be used herein are diethylene triamine penta methylene phosphonates.
Such phosphonate chelating agents are commercially available from Monsanto under the
trade name DEQUEST®.
[0059] 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.
[0060] 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.
[0061] Suitable amino carboxylates to be used herein include ethylene diamine tetra acetates,
diethylene triamine pentaacetates, diethylene triamine pentaacetate (DTPA),N- hydroxyethylethylenediamine
triacetates, nitrilotri-acetates, ethylenediamine tetrapropionates, triethylenetetraaminehexa-acetates,
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 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).
[0062] Suitable polyamine chelating agents include alkyl polyamines in general, such as
1,2 alkyl diamine, e.g , 1,2 propyl-diamine, 1,3 alkyl diamine, e.g., 1,3 propyl-diamine,
1,4 alkyl diamine, e.g., 1,4 butyl-diamine, propylene diamine, isopropylene diamine,
ethylene diamine. Highly preferred polyamine to be used herein is ethylene diamine
(EDA). The polyamines suitable to be used herein may be available from Union Carbide.
For example ethylene diamine may be commercially available under the name EDA® from
Union Carbide.
[0063] Particularly preferred chelating agents to be used herein are diethylene triamine
methylene phosphonate, ethylene N,N'-disuccinic acid, diethylene triamine pantaacetate,
ethylene diamine, glycine, salicylic acid, aspartic acid, glutamic acid, malonic acid
or mixtures thereof and highly preferred is salicylic acid. Salicylic acid may be
commercially available from Rhone-Poulenc under the name Salicylic Acid®.
[0064] Accordingly, the compositions of the present invention comprise up to 5% by weight
of the total composition, preferably from 0.01% to 3%, more preferably from 0.01%
to 1.5 % of a chelating agent or mixtures thereof.
[0065] As a further optional ingredient, the compositions of the present invention may comprise
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 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, 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.
[0066] Accordingly, the compositions of the present invention comprise up to 5% by weight
of the total composition, preferably from 0.01% to 2%, more preferably from 0.05%
to 1% of a radical scavenger or mixtures thereof.
[0067] The compositions herein can further comprise a variety of other optional ingredients,
such as builders, other chelants, other radical scavengers, enzymes, brighteners,
dyes, perfumes, and the like.
[0068] Depending on the type of spray-type dispenser to be used according to the present
invention, the compositions according to the present invention may be newtonian or
shear thinning. Optional ingredients may be added as appropriate to get the desired
rheology of the compositions.
[0069] By "newtonian" it is meant herein a composition having the same viscosity when submitted
to different shear stresses, e.g. when sprayed via a spray-type dispenser and when
adhered to the fabrics. By "shear thinning" it is meant herein a composition having
different viscosities when different shear stresses are applied to said composition.
For instance when sprayed via a spray-type dispenser such as for instance a trigger-sprayer
shear thinning compositions result in a shear thinning behaviour for ease of dispensing,
i.e. said compositions are thinner at higher shear rates. Thus said compositions pass
easily through the pumping mechanism of a spray-type dispenser where the shear rate
is high and immediately after recover their thickened character when reaching the
surface to be treated and adhere thereto.
[0070] As a further essential feature, the compositions according to the present invention
are packaged in a spray-type dispenser.
[0071] Suitable spray-type dispensers to be used according to the present invention include
aerosols as well as manually operated foam trigger-type dispensers sold for example
by Specialty Packaging Products, Inc. or Continental Sprayers, Inc. These types of
dispensers are disclosed, for instance, in US-4,646,973 and US-4,538,745 both to Focarracci.
Particularly preferred to be used herein are spray-type dispensers such as T 8500®
commercially available from Continental Spray International or T 8100® commercially
available from Canyon, Northen Ireland. In such a dispenser the liquid composition
is divided in fine liquid droplets resulting in a spray that is directed onto the
surface to be treated. Indeed, in such a spray-type dispenser the composition contained
in the body of said dispenser is directed through the spray-type dispenser head via
energy communicated to a pumping mechanism by the user as said user activates said
pumping mechanism. More particularly, in said spray-type dispenser head the composition
is forced against an obstacle, e.g. a grid or a cone or the like, thereby providing
shocks to help atomise the liquid composition, i.e. to help the formation of liquid
droplets.
[0072] An advantage of the present invention is that the liquid compositions according to
the present invention packaged in a spray-type dispenser and comprising a peroxygen
bleach and a surfactant may be applied uniformly to a relatively large area of a soiled
fabrics to be treated, thereby ensuring good cleaning performance on different types
of stains while being particularly safe to said soiled fabrics treated.
[0073] Another advantage of the present invention is that the liquid peroxygen bleach-containing
compositions of the present invention may be easily dispensed onto the soiled/stained
fabrics.
[0074] A further advantage according to the present invention is that fabrics pretreatment
is carried out in an economical way, i.e. no more product that what is really necessary
is used.
[0075] The present invention will be further illustrated by the following examples.
Examples
[0076] The following compositions were further made by mixing the listed ingredients in
the listed proportions. The listed proportions are expressed as weight %, based on
the total composition.
| Compositions(weight %) |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
| Neodol 23.3 |
6.4 |
2 |
-- |
12 |
-- |
3.5 |
6.4 |
| Neodol 45.7 |
8.6 |
-- |
6 |
-- |
3 |
6 |
8.6 |
| Dobanol 91-10 |
-- |
5 |
-- |
-- |
-- |
-- |
-- |
| Dobanol 23-6.5 |
-- |
-- |
6 |
-- |
-- |
-- |
-- |
| C25 AE3S |
2 |
-- |
-- |
-- |
-- |
-- |
-- |
| NaAS |
--- |
|
12 |
12 |
2 |
6 |
2 |
| H202 |
4 |
3 |
6 |
6 |
7 |
4 |
4 |
| Acetyl triethyl citrate |
3.5 |
-- |
3.5 |
3.5 |
-- |
2 |
3.5 |
| Octanoyl-caprolactam |
-- |
3.5 |
-- |
-- |
-- |
-- |
-- |
| Propanediol |
-- |
-- |
5 |
-- |
-- |
-- |
-- |
| Amine oxide |
-- |
-- |
3 |
-- |
-- |
-- |
-- |
| Benzyl alcohol |
-- |
-- |
-- |
-- |
-- |
3.0 |
-- |
| Water and minors |
-------------------------up to 100%------------------------- |
| H2SO4 up to pH 4 |
|
|
|
|
|
|
|
| NaAS stands for alkylsulfate |
| C25AE3S stands for C25 alkyl ethoxy sulfate |
[0077] By spraying the above compositions by means of a spray-type dispenser (e.g., a trigger-spray
commercially available under the trade name CalmarTS800-1A ®) onto soiled fabrics
to pretreat said fabrics excellent cleaning performance was obtained while improving
fabric safety and/or color safety.