Note: Descriptions are shown in the official language in which they were submitted.
~3~
1 C 7222 (R)
LEACHING PROCESS AND BLEACH COMPOSITIONS
This invention relates to an improved process for
bleaching substrates using a peroxyacid bleach compound
and to improved bleach compositions comprising a
peroxyacid bleach compound. The term "substrates" used
herein includes fibres, textiles and fabrics of both
animal and vegetabie origins, synthetics and mixtures
thereof, such as cottons, cellulosics, wool and other
protein fibres, bast fibres, acrylic and other synthetic
fibres, fabrics, and textiles.
An important trend in washing and bleaching practices in
household and industry has been the move towards lower
wash and bleaching temperatures, i.e. at about 40C and
below. In turn, this trend towards lower temperature
bleaching has necessitated improvement in the bleaching
performance of bleach (detergent) compositions,
particularly with respect to the stain removal of
bleachable stains and soilings, such as tea, wine,
coffee, etc. and the so-called dingy soils.
It is known that organic peroxyacids incorporated as
such or in the form of their precursors generating the
; peroxyacid in situ in bleach formulations are effective
bleaches at temperatures significantly below the boil-
wash temperatures, e.g. from above 40 to 60C. Their
effect at about 40C and below, however, is still far
from ideal.
US Patent no. 3,749,674 proposes the use of a quaternary
ammonium salt as so-called micelle catalyst for the
bleaching reaction of organic peroxyacids containing an
additional anionic group capable of forming bi-anionic
dimers in solution. Formation of these indispensible
transition complexes of the bleaching reaction is said
to be facilitated by positively charged micelles formed
2l~3~
2 C 7222 (R)
by the quaternary ammonium salts in solution.
GB-A-1,557,568 discloses granular laundry compositions
comprising an agglomerate of an organic peroxyacid
5 precursor and a quaternary ammonium surfactant. The
agglomerated quaternary ammonium compound present in the
same granular particles together with the peroxyacid
precursor is said to reduce the tendency of "pin-point"
spotting.
It has now been found, surprisingly, that the bleaching
performance of organic peroxyacid bleach compounds not
containing an additional negative charge can be boosted
to an unexpectedly substantial degree by the use of
specified low levels of a quaternary ammonium compound.
The quaternary ammonium compounds suitable in the
present invention are the mono-long chain type
quaternary ammonium compounds having the formula :
RlR2R3R4N+X
wherein Rl is a C8-Cl~ alkyl, alkenyl or alkaryl group,
: R2, R3 and R4 are each Cl-C3 alkyl groups, wherein the
total number of carbon atoms of Rl, R2, R3 and R4 is
from 15 to 21; and K is a counter-ion, including Cl-,
: 25 N03- or CH3S04-, and the poly-long chain type quaternary
ammonium compounds having the formula:
R.R.R.R.N+.X-
wherein at least two R's are C4-C12 alkyl, alkenyl or
alkaryl groups and the remaining R or R's are Cl-C12
alkyl, alkenyl or alkaryl groups, wherein the total
number of carbon atoms of all four R's is from 12 to 28,
preferably from 14 to 26; and K is a counter-ion,
including Cl-, N03- or CH3S04-.
; Preferred mono-long chain quaternary ammonium compounds
are those wherein Rl is an alkyl group having from 12-16
carbon atoms, preferably from 14-16 carbon atoms; R2, R3
and R4 are each methyl or ethyl, preferably methyl; and
I: the carbon atoms of Rl, R2, R3 and R4 total 17-19.
3 C 7222 (R)
Specific examples of such compounds are tetradecyl-
trimethyl ammonium nitrate; tetradecyl-trimethyl
ammonium methosulphate and hexadecyl-trimethyl ammonium
chloride.
Specific examples of suitable poly-long chain quaternary
ammonium compounds are:
(Cl2H2s)2-(cH3)2 N Cl
(C8Hl7)3.cH3.N .NO3
(C6Hl3)4.N+.cl-
Quaternary ammonium compounds are, of course, known in
the art as belonging to the class of cationic surface-
active agents. They are referred to in the prior art foruse as, among other things, emulsifiers, fabric
softeners, antistatics and disinfectants, or for use in
a conventional detergent functionality. They have also
been used, as claimed in US-A-3,749,674, to improve the
bleaching action of monopersulphates and certain types
of organic peroxyacids having an extra charged group
e.g. CO2-, C03- and SO3-, in addition to the peroxy
carboxylic group. It is said that this is due to the
quaternary ammonium compounds forming micelles in
solution which facilitate formation of bi-anionic
complexes typical for the afore-mentioned peroxyacid
compounds.
There has apparently been no realisation or appreciation
in the art of the beneficial effect that low levals of
quaternary ammonium compounds can have upon the
performance of organic peroxyacid bleach compounds which
in solution do not form bi-anionic dimers.
The present invention is based on the discovery that the
bleach performance of the more effective mono-peroxyacid
compounds not containing an additional charge can be
boosted still to a significant degree with mono- or
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4 C 7222 (R)
poly-long chain quaternary ammonium compounds as defined
hereinabove already at a level of as low as lx10-4 Molar
(M) in the bleach solution, improving steeply with
increasing levels up to about 12x10-4 Molar (M). Below
lx10-4 Molar the effect is too insignificant and above
12x10-4 Molar the effect generally plateaus or decreases
quickly. Preferred use levels are from 2 to lOx10-4 M,
particularly from 5 to lOx10-4 M.
The pH of the bleaching solution is not critical and
improvements of the bleaching and stain-removal effect
can be achieved under acid as well as under alkaline
conditions, e.g. at pH 4 to about 10.5, though a
bleaching pH of from about 7 to about 10 is generally
preferred.
Accordingly, in its broadest aspect the invention
provides in the use of a quaternary ammonium compound
having the formula :
R1R2R3R4N+X
wherein Rl is a C8-C18 alkyl, alkenyl or alkaryl group;
R2, R3 and R4 are each Cl-C3 alkyl groups, wherein the
total number of carbon atoms of Rl, R2, R3 and R4 is
from 15 to 21; and K is a counter-ion, including Cl-,
25 N03- or CH3S04-; or a quaternary ammonium compound
having the formula :
R.R.R.R.N+X-
wherein at least two R's are C4-C12 alkyl, alkenyl or
alkaryl groups and the remaining R or R's are C1-C12
alkyl, alkenyl or alkaryl groups, wherein the total
number of carbon atoms of all four R's is from 12 to 28,
preferably from 14 to 26; and K is a counter-ion,
including Cl-, N03- or CH3S0~-,
as a bleach booster for organic mono-peroxyacid
compounds not containing an additional negative charge,
in bleach solutions or bleaching (detergent)
compositions comprising said peroxyacid bleach compound.
C 7222 (R)
In another aspect, the invention provides a process for
bleaching substrates by treating the substrate with a
bleach solution comprising essentially a peroxyacid
bleach compound, characterized in that said bleach
solution comprises an organic mono-peroxyacid not
containing an additional negative charge and a
quaternary ammonium compound having the formula :
RlR2R3R4N+X
wherein R1 is a C8-C18 alkyl, alkenyl or alkaryl group,
R2, R3 and R~ are each C1-C3 alkyl groups wherein the
total number of carbon atoms of R1, R2, R3 and R~ is
from 15 to 21; and K is a counter-ion, including Cl-,
N03- or CH3S04-; or a quaternary ammonium compound
having the formula:
R.R.R.R.N+.X-
wherein at least two R's are C4-C12 alkyl, alkenyl or
alkaryl groups and the remaining R or R's are C1-C12
alkyl, alkenyl or alkaryl groups, wherein the total
number of carbon atoms of all four R's is from 12 to 28,
preferably form 14 to 26, and K is a counter-ion,
including Cl-, N03- or CH3S04-; as bleach booster for
said mono-peroxyacid, said quaternary ammonium compound
being present at a level of from lx10-4 to 12x10-4
Molar, preferably from 2x10-4 to lOx10-4 Molar.
Bleaching processes incorporating said low levels of
guaternary ammonium compounds can be carried out using
the mono-peroxyacid compound at the usual active oxygen
concentration in solution of about 0.3x10-3 Molar to
about 3x10-3 Molar, preferably from 0.3 to 1.5x10-3
Molar.
Advantageously, the organic mono-peroxyacid bleach
compound as defined above and the quaternary ammonium
compound as defined above are present in a molar ratio
of peroxyacid bleach compound to quaternary ammonium
compound of from about 50:1 to about 1:2.S, preferably
from about 25:1 to 1:2.
,~ ~3
6 C 7222 (R)
Compositions comprising the aforesaid mono-peroxyacid
compound bleach and the aforesaid quaternary ammonium
compound are effective over a wide pH range of between 4
and about 10.5, with optimal pH range lying between 7
and 9.5.
The peroxyacid bleach compounds utilized in the present
invention are the organic mono-peroxyacids and their
salts, having no other anionic moiety than the
peroxycarboxyl group.
A suitable class of organic peroxyacids can be
represented by compounds of the general formula :
o
HO-O-C-(O)n-R-H ,
wherein R is an alkylene or substituted alkylene group
containing 1 to 20 carbon atoms or an arylene group
containing from 6 to 8 carbon atoms, n is 0 or 1.
Specific examples of compounds of this type are
peracetic acid, peroxylauric acid, peroxynonanoic acid,
:~ peroxybenzoic acid, m-chloroperoxybenzoic acid, and p-
nitro-peroxybenzoic acid.
Another slass of peroxyacids usable herein are those as
: described in EP-A-0 325 288 which can be represented by
I; the general formula:
.~ O
- `N - (R)y - C~3H
O
o
wherein X is H, alkyl chain, a halogen or nitro-group in
any position of the aromatic ring; R is a straight or
branched cha.in lower Cl-C4-alkylene, preferably - CH2 -;
3~
7 C 7222 (~)
and y is between 1 and 12, preferably 3-8.
A preferred compound within this class is one having the
formula:
O
N (CH2)s - CO3H
o
phthaloylamino-peroxycaproic acid.
Still another class of peroxyacids usable herein is for
example the class of fatty peroxyacids and salts thereof
having amide moieties in the fatty chain as described in
EP-A-0 170 386 and EP-A-0 290,292, of the following
general formulae:
Rl - C - N - R2 _ CO3H and Rl - N - C - R2 - CO3H.
11 1 11
O R5 R5 O
wherein R1 and R2 are alkyl(ene), aryl(ene) or
alkaryl(ene~ groups containing from about 1 to about 14
carbon atoms and R5 is H or an alkyl, aryl or alkaryl
group containing from about 1 to about 10 carbon atoms.
Still further classes of organic mono-peroxyacids not
containing an additional anionic moiety are known, such
as the imidoperoxycarboxylic acids of EP-A-0 366 041.
Suitable peroxy acid salts for use herein are for
example the alkalimetal and magnesium salts thereof.
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8 C 7222 (R)
In systems wherein the peroxyacid is formed in situ from
its precursor or precursors, the peroxyacid can be
formed from the combination of an organic peroxyacid
precursor and hydrogen peroxide or a persalt of the
peroxyhydrate type, e.g. sodium perborate, by
perhydrolysis, or from a precursor which generates
peroxyacid by hydrolysis. Hence, various peroxyacid
precursors will fall within the scope of use in the
compositions of the invention. These include, for
example, benzoyl peroxide, which is capable of
generating peroxybenzoic acid.
Typical examples of peroxyacid precursors generating
peroxyacids by perhydrolysis are disclosed in e.g. US
l Patent 3,256,198; US Patent 3,272,750; GB Patent
836,988; ~B Patent 864,798; US Patent 4,283,301; US
Patent 4,486,327; US Patent 4,536,314; US Patent
3,686,127; US Patent 4,397,757; US Patent 4,751,015; and
EP-A-0 120 591.
Preferred peroxyacid precursors include sodium-4-
benzoyloxy benzene sulphonate; N,N,N',N'-tetraacet~1
ethylene diamine; sodium-l-methyl-2-benzoyloxy benzene-
4-sulphonate; and sodium-4-methyl-3-benzoyloxy benzoate,
and also those precursors as described in EP-A 0 170 386
and EP A 0 290 292. These precursors are utilized in the
presence of an alkaline source of hydrogen peroxide to
generate the corresponding peracids in situ.
Any of the hydrogen peroxide sources known in the art,
including H202, can be utilized together with peracid
precursors to generate peracids by a reaction, known as
perhydrolysis. Examples of hydrogen peroxide sources
utilizable herein include the alkali metal peroxides,
organic peroxides, such as urea peroxide, and the
inorganic "persalts" such as the alkali metal
perborates, percarbonates, perphosphates and
persilicates. Preferred compounds for use in the process
h 3 a I ~3 e.
9 C 7222 (R)
of the invention are hydrogen peroxide, sodium
percarbonate and sodium perborate tetra- or monohydrate.
The peroxyacid bleach compounds, the performance of
which can be boosted by the use of the quaternary
ammonium compounds as defined herein according to the
invention, therefore include the peroxyacids or
peroxyacid salts per se, as well as the above-described
peroxyacid precursor systems generating the peroxyacid
bleach in situ, the peroxyacids and sa]ts thereof being
preferred.
The process of the invention is effective at low
temperatures, e.g. at 40C and below, and can be
advantageously used in both household practice for the
effective bleaching and stain removal from textiles and
fabrics, as well as in industrial practice for various
purposes whereby the results are substantially improved
such as in the following areas:
1) The bleaching of cotton, cotton blends and
cellulosics by discontinuous methods whereby
temperatures can be reduced to significantly below the
boil;
2) Cold pad batch cctton or cellulosic bleaching in
shorter times than normal;
3) Continuous bleaching where steaming temperatures
and *imes lower than normal can be used;
4) Oxidative de-sizing;
5) Bleaching of wool and other protein fibres;
6) Bleaching bast fibres t and
7) The preparation of wool for the subsequent
exhaustion of shrink-resisting polymers.
The compositions of the invention having improved
bleaching effect, particularly at the lower temperature
region, can be used as a true bleaching composition, as
a bleach additive to a wash liquor- or for admixing with
a cleaning composition.
C 7222 (R)
In the case of a true bleaching composition and a bleach
additive, the composition will essentially comprise a
peroxyacid bleach compound, which may be an organic
peroxyacid or a peroxyacid salt or a precursor thereof,
as herein before described, and a quaternary ammonium
compound as defined hereinbefore.
When admixed to cleaning compositions forming effective
low temperature detergent bleach compositions, the
compositions are usable for washing and bleaching of
textiles, fabrics and fibres at low temperatures. In
such a case, the formulation will normally contain,
apart from the above essential ingredients, a surface-
active material, detergency builders and other known
ingredients of such formulations.
In that case, the bleaching composition is incorporated
therein in an amount such that, upon use, the detergent
bleach composition at a dosage of from 1-6 g/l will have
the peroxyacid and the quaternary ammonium compound in
the washing and bleaching solution at molar
concentrations within the ranges as advantageously
described hereinhefore. The lower dosage is normally
used under US washing conditions, whereas the higher
dosage is normal in European washing practice.
The surface-active material should preferably be non-
anionic in nature, since anionic surfactants may
neutralize the effect of the cationic quaternary
ammonium compound.
Suitable surface-active agents which can be utilized
herein are nonionic, zwitterionic and/or amphoteric in
nature, the total level of which may range from 0% up to
about 50% by weight, preferably from about 2% to 40% by
weight of the composition, most preferably 4 to 25% by
weight.
en
11 C 7222 (R~
Examples of suitable nonionic surface-active compounds
which may be used include in particular the reaction
products of alkylene oxides, usually ethylene oxide,
with alkyl (C6-C22~ phenols, generally 5-25 EO, i.e. 5-
25 units of ethylene oxides per molecule; thecondensation products of aliphatic (C8-C18) primary or
secondary linear or branched alcohols with ethylene
oxide, generally 6-30 EO, and products made by
condensation of ethylene oxide with the reaction
products of propylene oxide and ethylene diamine. Other
so-called nonionic surface-actives include alkyl
polyglycosides, long chain tertiary amine oxides, long
chain tertiary phosphine oxides and dialkyl sulphoxides.
Amounts of amphoteric or zwitterionic surface-active
compounds can also be used in the compositions of the
invention but this is not normally desired owing to
their relatively high cost. If any amphoteric or
zwitterionic detergent compounds are used, it is
generally in small amounts in compositions based on the
much more commonly used nonionic actives.
A further description of surface-active compounds of the
aforementioned classes can be found in Schwartz, Perry
Vol. II, 1958, "Detergents and Surface Active Agents"
and Schick, Vol. I, 1967, "Nonionic Surfactants".
The bleaching and cleaning compositions utilizing the
bleach composition of the invention will normally also
contain a detergency builder. Builder materials may be
selected from l calcium sequestrant materials, (2)
precipitating materials, (3) calcium ion-exchange
materials and (4) mixtures thereof.
Examples of calcium sequestrant builder materials
include alkali metal polyphosphates, such as sodium
tripolyphosphate, nitrilotriacetic acid and its water-
soluble salts; the alkali metal salts of
12 C 7222 (R)
carboxymethyloxy succinic acid, ethylene diamine
tetraacetic acid, oxydisuccinic acid, mellitic acid,
benzene polycarboxylic acids, citric acid; and
polyacetalcarboxylates as disclosed US Patents 4,144,225
and 4,146,495.
Examples of precipitating builder materials include
sodium orthophosphate, sodium carbonate and long-chain
fatty acid soaps.
Examples of calcium ion-exchange builder materials
include the various types of water-insoluble crystalline
or amorphous aluminosilicates, of which zeolites are the
best-known representatives.
In particular, the compositions of the invention may
contain any one of the organic or inorganic builder
materials, such as sodium or potassium tripolyphosphate,
sodium or potassium pyrophosphate, sodium or potassium
orthophosphate, sodium carbonate, the sodium salt of
nitrilotriacetic acid, sodium citrate, carboxymethyl
malonate, carboxymethyl succinate arld the water-
insoluble crystalline or amorphous aluminosilicate
builder materials, or mixtures thereof.
These builder materials may be present at a level of,
for example, from 5 to 80% by weight, preferably from 10
to 60% by weight.
Apart from the components already mentioned, a fully
formulated bleaching and cleaning composition of the
invention can contain any of the conventional additives
in the amounts in which such materials are normally
employed in fabric-washing detergent compositions.
Examples of these additives include lather boosters,
such as alkanolamides, particularly the
monoethanolamides derived from palmkernel fatty acids
and coconut fatty acids, lather depressants such as
2 r
13 C 7222 (R)
alkyl phosphates and silicones, anti-redeposition agents
such as sodium caxboxymethyl cellulose and alkyl or
substituted alkyl cellulose ethers, stabilizers such as
ethylene diamine tetraacetic acid, fabric-softening
agents, inorganic salts such as sodium sulphate, and,
usually present in very small amounts, fluorescent
agents, perfumes, enzymes such as proteases, cellulases,
lipases and amylases, germicides and colorants.
The peroxyacid compounds usable in the bleach or bleach
and detergent compositions of the invention may be
present in an amount of from 0.5-65~ by weight of the
total composition, preferably from 1-50%, particularly
from 1-25% by weight.
The higher side of the range is usually applied to true
bleaching composi$ions which can be used as such for
bleaching fabrics or as a bleach adjunct to detergent
compositions. The lower side of the range applies to
fully formulated heavy duty bleaching detergent
compositions. In such compositions the peroxyacid
compound is usually present at a level within the range
of 0.5-15% by weight, preferably from 1-10% by weight.
The invention will now be further illustrated by way of
the following examples.
14 C 7222 (R)
EXAMPLE 1
Bleaching experiments were carried out on tea-stained
test cloths. The tea-stained test cloths were treated
with bleaching solution at 40~C containing p-nitro
peroxybenzoic acid in a concentration of 1.2x10-3 Molar
for 30 minutes, at pH 4, pH 7.1 and pH 10 with and
without tetradecyl-trimethyl ammonium nitrate (TDTAN)
added at a concentration of 5x10-4 Molar.
The bleaching performances of each test were measured
using a reflectophotometer and the results expressed as
difference in reflectance (OR) are tabulated below:
TABLE 1
~R460*
TDTAN pH=4 pH=7.1 pH=10
(-) 15.0 17.0 4.0
(~) 27.3 29.7 20.8
EXAMPLE II
In this Example the effect of TDTAN on the bleaching
performance of various peroxyacids is demonstrated. The
bleaching experiments were carried out with bleachiny
solutions/ again at 40C and for 30 minutes, using tea-
stained test pieces. The peroxyacids used were m-chloro-
peroxybenzoic acid (MCPBA), peroxynonanoic acid (PNA)and peroxybenzoic acid (P3A3, incorporated therein at a
concentration of 1.2 x 10-3M and the bleaching
solutions were adjusted to pH 10.
The following results were obtained:
Y
C 7222 (R)
TABLE 2
TDTAN concentration ~R460*
(xlO- M)
MCPBA PNA PBA
o 4.5 6.8 4.5
22.4 12.9 16.7
EXAMPLE III
When the bleaching experiments of Examples I and II were
repeated in a Tergotometer together with a detergent
base powder composition, dosed at 5 g/l, of the
following formulation, the same significant bleach
boosting effects were observed.
Base powder composition % by weiaht
Nonionic fatty alcohol-7 ethoxylate 7.0
: MaIeic acidjacrylic acid copolymer 4.0
(Sokolan CP5 ex BASF)
Zeolite 4A 30.0
Sodium triphosphate 15.0
Sodium sulphate 35.0
Sodium ethylene diamine tetraacetate 0.3
25 Sodium carboxymethyl cellulose 0.6
Ethylene diam~ne tetra~methylene phosphonate) 0.6
(Dequest ~J 2047~
Water + fluorescer 7.5
