Field of the Invention
[0001] The invention relates to activation of bleaches employing peroxy compounds including
hydrogen peroxide or hydrogen peroxide adducts, which liberate hydrogen peroxide in
aqueous solution, and peroxy acids (or precursors thereof); to compounds that activate
or catalyse peroxy compounds; to bleach compositions, including detergent bleach compositions,
which contain a catalyst for peroxy compounds; and to processes for bleaching and/or
washing substrates using the aforementioned types of compositions.
[0002] In particular, the present invention is concerned with the novel use of iron compounds
as catalysts for the bleach activation of peroxy compounds.
Background of the Invention.
[0003] Peroxide bleaching agents for use in laundering have been known for many years. Such
agents are effective in removing stains, such as tea, fruit, and wine stains, from
clothing at or near boiling temperatures. The efficacy of peroxide bleaching agents
drops off sharply at temperatures below 60°C.
[0004] Previous patent applications dealt with environmentally acceptable manganese ions
and complexes. US-A-4,728,455 discusses the use of Mn(III)-gluconate as peroxide bleach
catalyst with high hydrolytic and oxidative stability; relatively high ratios of ligand
(gluconate) to Mn are, however, needed to obtain the desired catalytic system. Moreover,
the performance of these Mn-based catalysts is inadequate when used for bleaching
in the low-temperature region of about 20°-40°C, and they are restricted in their
efficacy to remove a wide range of stains.
[0005] In several patent documents, for instance EP-A-458,379, novel triazacyclononane-based
manganese complexes are disclosed, which display a high catalytic oxidation activity
at low temperatures that is particularly suitable for bleaching purposes. A major
improvement of the bleaching activity could be obtained by virtue of the fact that
these compounds are stable under washing conditions, e.g. high alkalinity and oxidizing
environment (as a result of the presence of hydrogen peroxide or peroxy acids).
[0006] In addition to the above-mentioned stain removal, dye transfer is a well-known problem
in the art and has been addressed in various ways. For instance, an improved dye transfer
inhibition has been obtained by using Fe-porphyrin and Fe-phthalocyanine complexes
(see EP-A-537,381, EP-A-553,607, EP-A-538,228).
[0007] It is well known that the stability, of Fe-co-ordination complexes in alkaline aqueous
media in the presence of peroxide compounds is very poor. In BP-A-537,381 and EP-A-553,607,
methods are disclosed for improvement in this respect.
[0008] This poor stability of Fe-co-ordination species has resulted in the necessity of
very low concentrations of peroxide and, additionally, the use of polymers (see EP-A-538,228).
These measures, however, only reduce the negative effects of the above-indicated poor
stability to some extent and do not provide a complete solution to this problem.
[0009] In WO-A-9534628, it has been shown that the use of iron compounds containing pentadentate
nitrogen-containing ligands, in particular the use of N,N-bis(pyridin-2-ylmethyl)-bis(pyridin-2-yl)methylamine,
as bleaching and oxidation catalysts, resulted in a favourable bleaching activity,
dye bleaching activity and oxidation activity in general.
[0010] We have now surprisingly found that a significantly improved catalytic oxidation
activity of the Fe-coordination complex can be obtained by substituting the H-atom
of the C-H group of the methylamine moiety present in the ligands according to WO-A-9534628,
by other groups.
[0011] As a consequence, these new iron compounds were found to provide favourable stain
removal in the presence of hydrogen peroxide or peroxy acids. Furthermore, an improved
bleaching activity has been particularly noted in alkaline aqueous solutions containing
peroxy compounds at concentrations generally present in the wash liquor during the
fabric washing cycle.
[0012] Additionally, these new iron compounds exhibit remarkable dye transfer inhibition
properties, and, alternatively, oxidation of organic substrates such as olefins, alcohols
and unactivated hydrocarbons.
Definition of the Invention
[0013] In one aspect, the present invention provides a bleach and oxidation catalyst comprising
an Fe-complex having formula (A):
[LFeX
n]
zY
q (A)
or precursors thereof, in which
Fe is iron in the II, III,IV or V oxidation state;
X represents a coordinating species such as H2O, ROH, NR3, RCN, OH, OOH, OOR-, RS-, RO-, RCOO-, OCN-, SCN-, N3-, CN-, F-, Cl-, Br-, I-, O2-, NO3-, NO2-, SO42-, SO32-, PO43- or aromatic N donors such as pyridines, pyrazines, pyrazoles, imidazoles, benzimidazoles,
pyrimidines, triazoles and thiazoles with R being H, optionally substituted alkyl
or optionally substituted aryl;
n is an integer ranging from 0-3;
Y is a counter ion, the type of which is dependent on the charge of the complex;
q = z/[charge Y];
z denotes the charge of the complex and is an integer which can be positive, zero
or negative; if z is positive, Y is an anion such as F-, Cl-, Br-, I-, NO3-, BPh4-, ClO4-, BF4-, PF6-, RSO3-, RSO4-, SO42-, CF2SO3- or RCOO- ; if z is negative, Y is a common cation such as an alkali metal, alkaline earth
metal or (alkyl)ammonium cation; and
L represents a ligand of general formula (B):

which contains at least five nitrogen atoms and in which the substituent groups R1-R5 are independently selected from hydrogen, hydroxy, halogen, nitroso, formyl, carboxyl,
and esters and salts thereof, carbamoyl, sulfo, and esters and salts hereof, sulfamoyl,
nitro, amino, C0-C20-alkyl-hydroxy, C0-C20-alkyl-halogen, C0-C20-alkyl-nitroso, C0-C20-alkyl-formyl, C0-C20-alkyl-carboxyl, and esters and salts thereof, C0-C20-alkyl-carbamoyl, C0-C20-alkyl-sulfo, and esters and salts hereof, C0-C20-alkyl-sulfamoyl, C0-C20-alkyl-amino, C0-C20-alkylaryl, C0-C20-alkylheteroaryl, C0-C20 alkyl, C0-C8 alkoxy, carbonyl-C0-C6-alkoxy, and aryl-C0-C6-alkyl,
provided that R1 does not represent hydrogen.
[0014] In another aspect, the present invention provides a bleaching composition comprising
a peroxy compound bleach preferably selected from hydrogen peroxide, hydrogen peroxide-liberating
or -generating compounds, peroxyacids and their salts, and mixtures thereof, optionally
together with peroxyacid bleach precursors, and a catalyst according to the present
invention.
Detailed Description of the Invention
[0015] Generally, the Fe-complex catalyst of the invention may be used in a bleaching system
comprising a peroxy compound or a precursor thereof, and may be suitable for use in
the washing and bleaching of substrates including laundry, dishwashing and hard surface
cleaning. Alternatively, the Fe-complex catalyst of the invention may be used for
bleaching in the textile, paper and woodpulp industries, as well as in waste water
treatment.
[0016] As already stated, an advantage of the Fe-complex catalysts according to the present
invention is that they exhibit a remarkably high oxidation activity in alkaline aqueous
media in the presence of peroxy compounds.
[0017] A second advantage of the new Fe-complex catalysts of the invention is that they
show good bleaching activity at a broader pH range (generally pH 6-11) than those
observed for the previously disclosed iron complexes. Their performance was especially
improved at pH of around 10. This advantage may be particularly beneficial in view
of the current detergent formulations that employ rather alkaline conditions, as well
as the tendency to shift the pH during fabric washing from alkaline (typically, a
pH of 10) to more neutral values. Furthermore, this advantage may be beneficial when
using the present iron complex catalyst in machine dishwash formulations.
[0018] An additional advantage is that such compounds are active as dye-transfer inhibition
agents, as shown in Example 5.
[0019] Another advantage is that the catalysts of the invention have a relatively low molecular
weight and, consequently, are very weight-effective.
[0020] Precursors of the active Fe-complex catalysts of the invention can be any iron coordination
complex, which, under fabric washing conditions, is transformed into the active iron
complex of general formula (A). Alternatively, the precursor of the Fe-complex of
the invention can be a mixture of an iron salt, such as Fe(NO
3)
3, and the ligand L.
[0021] A preferred class of ligands is that of compounds of general formula (B), in which
R
2, R
3, R
4, R
5 are independently chosen from C
0-C
5 alkyl substituted with nitrogen-containing heterocyclic aromatic groups, such as
pyridines, pyrazines, pyrazoles, imidazoles, benzimidazoles, thiazoles, triazoles
and pyrimidines, in particular pyridines, and in which the substituent group R
1 represents any group other than hydrogen, e.g. hydroxy, halogen, nitroso, formyl,
carboxyl, and esters and salts thereof, carbamoyl, sulfo, and esters and salts hereof,
sulfamoyl, nitro, amino, C
0-C
20-alkyl-hydroxy, C
0-C
20-alkyl-halogen, C
0-C
20-alkyl-nitroso, C
0-C
20-alkyl-formyl, C
0-C
20-alkyl-carboxyl, and esters and salts thereof, C
0-C
20-alkyl-carbamoyl, C
0-C
20-alkyl-sulfo, and esters and salts hereof, C
0-C
20-alkyl-sulfamoyl, C
0-C
20-alkyl-amino, C
0-C
20-alkylaryl, C
0-C
20-alkylheteroaryl, C
0-C
20 alkyl, C
0-C
8 alkoxy, carbonyl-C
0-C
6-alkoxy, aryl-C
0-C
6-alkyl, whereby the carbamoyl, sulfamoyl and amino groups are optionally further substituted
by any other group.
[0022] A more preferred class of ligands is that of compounds of general formula (B), in
which the substituent group R
1 is selected from C
0-C
20 alkylaryl, C
0-C
20 alkylheteroaryl, and C
0-C
20 alkyl, and in which the substituent groups R
2, R
3, R
4, and R
5 are independently chosen from C
0-C
5 alkyl substituted with a pyridine ring.
[0023] Examples of preferred ligands in their simplest forms are:
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane;
N,N-bis(pyrazol-1-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane;
N,N-bis(pyrazol-1-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane;
N,N-bis(imidazol-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane;
N,N-bis(imidazol-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane;
N,N-bis(1,2,4-triazol-1-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane;
N,N-bis(1,2,4-triazol-1-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyrazol-1-yl)-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyrazol-1-yl)-2-phenyl-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(imidazol-2-yl)-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(imidazol-2-yl)-2-phenyl-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(1,2,4-triazol-1-yl)-1-aminoethane;
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(1,2,4-triazol-1-yl)-1-aminoethane;
[0024] More preferred ligands are:
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminohexane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(4-sulfonic acid-phenyl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(pyridin-2-yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(pyridin-3 -yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(pyridin-4-yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(1-alkyl-pyridinium-4-yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(1-alkyl-pyridinium-3-yl)-1-aminoethane,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-(1-alkyl-pyridinium-2-yl)-1-aminoethane.
[0025] The most preferred ligands are:
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane, hereafter referred
to as MeN4Py,
N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane, hereafter
referred to as BzN4Py.
[0026] Suitable counter ions are those which give rise to the formation of storage-stable
solids. Combination of the preferred iron complexes with the counter ion Y preferably
involves counter ions selected from RCOO
-, BPh
4-, ClO
4-, BF
4-, PF
6-, RSO
3-, RSO
4-, SO
42-, NO
3-, F
-, Cl
-, Br
-, I
- wherein R=H, optionally substituted phenyl, naphthyl or C
1-C
4 alkyl. Preferred co-ordinating species X are selected from CH
3CN, pyridine, H
2O, Cl
-, OR
-, and OOH
-, wherein R=H, optionally substituted phenyl, naphthyl or C
1-C
4 alkyl.
[0027] The effective level of the Fe-complex catalyst, expressed in terms of parts per million
(ppm) of iron in an aqueous bleaching solution, will normally range from 0.001 ppm
to 100 ppm, preferably from 0.01 ppm to 20 ppm, most preferably from 0.1 ppm to 10
ppm. Higher levels may be desired and applied in industrial bleaching processes, such
as textile and paper pulp bleaching. The lower range levels are preferably used in
domestic laundry operations.
The detergent bleach composition
[0028] The bleaching composition of the invention has particular application in detergent
formulations, to form a new and improved detergent bleach composition within the purview
of the invention comprising a peroxy compound bleach as defined above, the aforesaid
Fe-complex catalyst having general formula (A), a surface-active material and a detergency
builder.
[0029] The Fe-complex catalyst will be present in the detergent bleach composition of the
invention in amounts so as to provide the required level in the wash liquor. Generally,
the Fe-complex catalyst level in the detergent bleach composition corresponds to an
iron content of from 0.0005% to 0.5% by weight. When the dosage of detergent bleach
composition is relatively low,
e.g. about 1-2 g/l, the Fe content in the formulation is suitably 0.0025 to 0.5%, preferably
0.005 to 0.25% by weight. At higher product dosages, as used
e.g. by European consumers, the Fe content in the formulation is suitably 0.0005 to 0.1%,
preferably 0.001 to 0.05% by weight.
[0030] Detergent bleach compositions of the invention are effective over a wide pH-range
of between 7 and 13, with optimal pH-range lying between 8 and 11.
The peroxy bleaching compound
[0031] The peroxy bleaching compound may be a compound which is capable of yielding hydrogen
peroxide in aqueous solution. Hydrogen peroxide sources are well known in the art.
They include the alkali metal peroxides, organic peroxides such as urea peroxide,
and inorganic persalts, such as the alkali metal perborates, percarbonates, perphosphates
persilicates and persulphates. Mixtures of two or more such compounds may also be
suitable.
[0032] Particularly preferred are sodium perborate tetrahydrate and, especially, sodium
perborate monohydrate. Sodium perborate monohydrate is preferred because of its high
active oxygen content. Sodium percarbonate may also be preferred for environmental
reasons. The amount thereof in the composition of the invention usually will be within
the range of about 5-35 % by weight, preferably from 10-25 % by weight.
[0033] Another suitable hydrogen peroxide generating system is a combination of a C
1-C
4 alkanol oxidase and a C
1-C
4 alkanol, especially a combination of methanol oxidase (MOX) and ethanol. Such combinations
are disclosed in WO-A-9507972, which is incorporated herein by reference.
[0034] Alkylhydroxy peroxides are another class of peroxy bleaching compounds. Examples
of these materials include cumene hydroperoxide and t-butyl hydroperoxide.
[0035] Organic peroxyacids may also be suitable as the peroxy bleaching compound. Such materials
normally have the general formula:

wherein R is an alkyl- or alkylidene- or substituted alkylene group containing from
1 to about 20 carbon atoms, optionally having an internal amide linkage; or a phenylene
or substituted phenylene group; and Y is hydrogen, halogen, alkyl, aryl, an imido-aromatic
or non-aromatic group, a COOH or COOOH group or a quaternary ammonium group.
[0036] Typical monoperoxy acids useful herein include, for example:
(i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-α-naphthoic
acid;
(ii) aliphatic, substituted aliphatic and arylalkyl monoperoxyacids, e.g. peroxylauric
acid, peroxystearic acid and N,N-phthaloylaminoperoxy caproic acid (PAP); and
(iii) 6-octylamino-6-oxo-peroxyhexanoic acid.
[0037] Typical diperoxyacids useful herein include, for example:
(iv) 1,12-diperoxydodecanedioic acid (DPDA);
(v) 1,9-diperoxyazelaic acid;
(vi) diperoxybrassylic acid; diperoxysebacic acid and diperoxyisophthalic acid;
(vii) 2-decyldiperoxybutane-1,4-dioic acid; and
(viii) 4,4'-sulphonylbisperoxybenzoic acid.
[0038] Also inorganic peroxyacid compounds are suitable, such as for example potassium monopersulphate
(MPS). If organic or inorganic peroxyacids are used as the peroxygen compound, the
amount thereof will normally be within the range of about 2-10% by weight, preferably
from 4-8 % by weight.
[0039] All these peroxy compounds may be utilized alone or in conjunction with a peroxyacid
bleach precursor and/or an organic bleach catalyst not containing a transition metal.
Generally, the bleaching composition of the invention can be suitably formulated to
contain from 2 to 35% , preferably from 5 to 25% by weight, of the peroxy bleaching
agent.
[0040] Peroxyacid bleach precursors are known and amply described in literature, such as
in GB-A-836988; GB-A-864,798; GB-A-907,356; GB-A-1,003,310 and GB-A-1,519,351; DE-A-3,337,921;
EP-A-0,185,522; EP-A-0,174,132; EP-A-0,120,591; and US-A-1,246,339; US-A-3,332,882;
US-A-4,128,494; US-A-4,412,934 and US-A-4,675,393.
[0041] Another useful class of peroxyacid bleach precursors is that of the cationic i.e.
quaternary ammonium substituted peroxyacid precursors as disclosed in US-A-4,751,015
and US-A-4,397,757, in EP-A-0,284,292 and EP-A-331,229. Examples of peroxyacid bleach
precursors of this class are:
2-(N,N,N-trimethyl ammonium) ethyl sodium-4-sulphophenyl carbonate chloride- (SPCC);
N-octyl,N,N-dimethyl-N10-carbophenoxy decyl ammonium chloride - (ODC);
3-(N,N,N-trimethyl ammonium) propyl sodium-4-sulphophenyl carboxylate; and
N,N,N-trimethyl ammonium toluyloxy benzene sulphonate.
[0042] A further special class of bleach precursors is formed by the cationic nitriles as
disclosed in EP-A-303,520; EP-A-458,396 and EP-A-464,880.
[0043] Any one of these peroxyacid bleach precursors can be used in the present invention,
although some may be more preferred than others.
[0044] Of the above classes of bleach precursors, the preferred classes are the esters,
including acyl phenol sulphonates and acyl alkyl phenol sulphonates; the acyl-amides;
and the quaternary ammonium substituted peroxyacid precursors including the cationic
nitriles.
[0045] Examples of said preferred peroxyacid bleach precursors or activators are sodium-4-benzoyloxy
benzene sulphonate (SBOBS); N,N,N'N'-tetraacetyl ethylene diamine (TAED); sodium-1-methyl-2-benzoyloxy
benzene-4-sulphonate; sodium-4-methyl-3-benzoloxy benzoate; 2-(N,N,N-trimethyl ammonium)
ethyl sodium-4-sulphophenyl carbonate chloride (SPCC); trimethyl ammonium toluyloxy-benzene
sulphonate; sodium nonanoyloxybenzene sulphonate (SNOBS); sodium 3,5,5-trimethyl hexanoyloxybenzene
sulphonate (STHOBS); and the substituted cationic nitriles.
[0046] The precursors may be used in an amount of up to 12 %, preferably from 2-10% by weight,
of the composition.
[0047] As an alternative to the above described peroxide generating systems, molecular oxygen
may be used as the oxidant.
The surface-active material
[0048] The detergent bleach composition according to the present invention generally contains
a surface-active material in an amount of from 10 to 50% by weight.
[0049] Said surface-active material may be naturally derived, such as soap, or a synthetic
material selected from anionic, nonionic, amphoteric, zwitterionic, cationic actives
and mixtures thereof. Many suitable actives are commercially available and are fully
described in the literature, for example in "Surface Active Agents and Detergents",
Volumes I and II, by Schwartz, Perry and Berch.
[0050] Typical synthetic anionic surface-actives are usually water-soluble alkali metal
salts of organic sulphates and sulphonates having alkyl radicals containing from about
8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion
of higher aryl radicals. Examples of suitable synthetic anionic detergent compounds
are sodium and ammonium alkyl sulphates, especially those obtained by sulphating higher
(C
8-C
18) alcohols produced, for example, from tallow or coconut oil; sodium and ammonium
alkyl (C
9-C
10) benzene sulphonates, particularly sodium linear secondary alkyl (C
10-C
15) benzene sulphonates; sodium alkyl glyceryl ether sulphates, especially those ethers
of the higher alcohols derived from tallow or coconut oil fatty acid monoglyceride
sulphates and sulphonates; sodium and ammonium salts of sulphuric acid esters of higher
(C
9-C
18) fatty alcohol alkylene oxide, particularly ethylene oxide, reaction products; the
reaction products of fatty acids such as coconut fatty acids esterified with isethionic
acid and neutralised with sodium hydroxide; sodium and ammonium salts of fatty acid
amides of methyl taurine; alkane monosulphonates such as those derived by racting
alpha-olefins (C
8-C
20) with sodium bisulphite and those derived by reaction paraffins with SO
2 and Cl
2 and then hydrolysing with a base to produce a random sulphonate; sodium an ammonium
C
7-C
12 dialkyl sulphosuccinates; and olefin sulphonates which term is used to describe material
made by reacting olefins, particularly C
10-C
20 alpha-olefins, with SO
3 and then neutralising and hydrolysing the reaction product. The preferred anionic
detergent compounds are sodium (C
10-C
15) alkylbenzene sulphonates, sodium (C
16-C
18) alkyl ether sulphates.
[0051] Examples of suitable nonionic surface-active compounds which may be used, preferably
together with the anionic surface-active compounds, include, in particular, the reaction
products of alkylene oxides, usually ethylene oxide, with alkyl (C
6-C
22) phenols, generally 5-25 EO,
i.e. 5-25 units of ethylene oxides per molecule; and the condensation products of aliphatic
(C
8-C
18) primary or secondary linear or branched alcohols with ethylene oxide, generally
2-30 EO. Other so-called nonionic surface-actives include alkyl polyglycosides, sugar
esters, long-chain tertiary amine oxides, long-chain tertiary phosphine oxides and
dialkyl sulphoxides.
[0052] 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 synthetic anionic
and nonionic actives.
[0053] As disclosed by EP-A-544,490, the performance of the hereinbefore described bleach
catalyst may be dependent upon the active detergent system and the builder system
present in the detergent bleach composition of the invention.
[0054] The detergent bleach composition of the invention will preferably comprise from 1-15
% wt of anionic surfactant and from 10-40 % by weight of nonionic surfactant. In a
further preferred embodiment the detergent active system is free from C
16-C
12 fatty acids soaps.
The detergency builder
[0055] The composition of the invention normally and preferably also contains a detergency
builder in an amount of from about 5-80 % by weight, preferably from about 10-60 %
by weight.
[0056] Builder materials may be selected from 1) calcium sequestrant materials, 2) precipitating
materials, 3) calcium ion-exchange materials and 4) mixtures thereof.
[0057] 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 carboxymethyloxy succinic acid, ethylene diamine tetraacetic
acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, citric acid;
and polyacetal carboxylates as disclosed in US-A-4,144,226 and US-A-4,146,495.
[0058] Examples of precipitating builder materials include sodium orthophosphate and sodium
carbonate.
[0059] 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,
e.g. zeolite A, zeolite B (also know as zeolite P), zeolite C, zeolite X, zeolite
Y and also the zeolite P-type as described in EP-A-0384070.
[0060] In particular, the compositions of the invention may contain any one of the organic
and inorganic builder materials, though, for environmental reasons, phosphate builders
are preferably omitted or only used in very small amounts.
[0061] Typical builders usable in the present invention are, for example, sodium carbonate,
calcite/carbonate, the sodium salt of nitrilotriacetic acid, sodium citrate, carboxymethyloxy
malonate, carboxymethyloxy succinate and the water-insoluble crystalline or amorphous
aluminosilicate builder material, each of which can be used as the main builder, either
alone or in admixture with minor amounts of other builders or polymers as co-builder.
[0062] It is preferred that the composition contains not more than 5% by weight of a carbonate
builder, expressed as sodium carbonate, more preferable not more than 2.5 % by weight
to substantially nil, if the composition pH lies in the lower alkaline region of up
to 10.
Other ingredients
[0063] Apart form the components already mentioned, the detergent bleach composition of
the invention can contain any of the conventional additives in amounts of which such
materials are normally employed in fabric washing detergent compositions. Examples
of these additives include buffers such as carbonates, lather boosters, such as alkanolamides,
particularly the monoethanol amides derived from palmkernel fatty acids and coconut
fatty acids; lather depressants, such as alkyl phosphates and silicones; anti-redeposition
agents, such as sodium carboxymethyl cellulose and alkyl or substituted alkyl cellulose
ethers; stabilizers, such as phosphonic acid derivatives (i.e. Dequest® types); fabric
softening agents; inorganic salts and alkaline buffering agents, such as sodium sulphate
and sodium silicate; and usually in very small amounts, fluorescent agents; perfumes;
enzymes, such as proteases, cellulases, lipases, amylases and oxidases; germicides
and colourants.
[0064] When using a hydrogen peroxide source, such as sodium perborate or sodium percarbonate,
as the bleaching compound, it is preferred that the composition contains not more
than 5 % by weight of a carbonate buffer, expressed as sodium carbonate, more preferable
not more than 2.5% by weight to substantially nil, if the composition pH lies in the
lower alkaline region of up to 10.
[0065] Of the additives, transition metal sequestrants such as EDTA and the phosphonic acid
derivatives,
e.g. ethylene diamine tetra-(methylene phosphonate)-EDTMP- are of special importance,
as not only do they improve the stability of the catalyst/H
2O
2 system and sensitive ingredients, such as enzymes, fluorescent agents, perfumes and
the like, but also improve the bleach performance, especially at the higher pH region
of above 10, particularly at pH 10.5 and above.
[0066] The invention will now be further illustrated by way of the following non-limiting
examples:
Example 1
Preparation of MeN4Py ligand
[0067] The precursor N
4Py.HClO
4 was prepared as follows:
To pyridyl ketone oxim (3 g, 15.1 mmol) was added ethanol (15 ml), concentrated ammonia
solution (15 mL) and NH
4OAc (1.21 g, 15.8 mmol). The solution was warmed until reflux. To this solution was
added 4.64 g Zn in small portions. After the addition of all Zn, the mixture was refluxed
for 1 hour and allowed to cool to ambient temperature. The solution was filtered and
water (15 ml) was added. Solid NaOH was added until pH>>10 and the solution was extracted
with CH
2Cl
2 (3 x 20 ml). The organic layers were dried over Na
2SO
4 and evaporated until dryness. Bis(pyridin-2-yl)methylamine (2.39 g, 12.9 mmol) was
obtained as a colourless oil in 86% yield, showing the following analytical characteristics:
1H NMR (360 MHz, CDCl
3): δ 2.64 (s, 2H, NH
2), 5.18 (s, 1H, CH), 6.93 (m, 2H, pyridine), 7.22 (m, 2H, pyridine), 7.41 (m, 2H,
pyridine), 8.32 (m, 2H, pyridine);
13C NMR (CDCl
3): δ 62.19 (CH), 121.73 (CH), 122.01 (CH), 136.56 (CH), 149.03 (CH), 162.64 (Cq).
[0068] To picolylchloride hydrochloride (4.06 g, 24.8 mmol) was added, at 0°C, 4.9 ml of
a 5N NaOH solution. This emulsion was added by means of a syringe to bis(pyridin-2-yl)methylamine
(2.3 g, 12.4 mmol) at 0°C. Another 5 ml of a 5N NaOH solution was added to this mixture.
After warming to ambient temperature, the mixture was stirred vigorously for 40 hrs.
The mixture was put in an ice bath and HClO
4 was added until pH<1, whereupon a brown solid precipitated. The brown precipitate
was collected by filtration and recrystallized from water. While stirring, this mixture
was allowed to cool to ambient temperature, whereupon a light-brown solid precipitated
which was collected by filtration and washed with cold water and air-dried (1.47 g).
[0069] From 0.5 g of the perchlorate salt of N
4Py prepared as described above, the free amine was obtained by precipitating the salt
with 2N NaOH and subsequently by extraction with CH
2Cl
2. To the free amine was added under argon 20 ml of dry tetrahydrofuran freshly distilled
from LiAlH
4 The mixture was stirred and cooled to -70 °C by an alcohol / dry ice bath. Now 1
ml of 2.5 N butyllithium solution in hexane was added giving an immediate dark red
colour. The mixture was allowed to warm to -20 °C and now 0.1 ml of methyl iodide
was added. The temperature was kept to -10 °C for 1 hour. Subsequently 0.5 g of ammonium
chloride was added and the mixture was evaporated in vacuo. To the residue water was
added and the aqueous layer was extracted with dichloromethane. The dichloromethane
layer was dried on sodium sulfate, filtered and evaporated giving 0.4 g residue. The
residue was purified by crystallisation from ethyl acetate and hexane giving 0.2 g
of creamish powder (50% yield) showing the following analytical characteristics:
1H NMR (400 MHz, CDCl
3): δ (ppm) 2.05 (s, 3H, CH
3), 4.01 (s, 4H, CH
2), 6.92 (m, 2H, pyridine), 7.08 (m, 2H, pyridine), 7.39 (m, 4H pyridine), 7.60 (m,
2H, pyridine), 7.98 (d, 2H, pyridine), 8.41 (m, 2H pyridine), 8.57 (m, 2H, pyridine).
13C NMR (100.55 MHz, CDCl
3); δ (ppm) 21.7 (CH
3), 58.2 (CH
2), 73.2 (Cq), 121.4 (CH), 121.7 (CH), 123.4 (CH), 123.6 (CH), 136.0 (CH), 148.2 (Cq),
148.6 (Cq), 160.1 (Cq), 163.8 (Cq).
[0070] Subsequently [(MeN
4Py)Fe(CH
3CN)](ClO
4)
2, hereinafter referred to as Fe(MeN
4Py), was prepared as follows:
[0071] To a solution of 0.27 g of MeN
4Py in 12 ml of a mixture of 6 ml acetonitrile and 6 ml methanol was added 350 mg Fe(ClO
4)
2.6H
2O immediately a dark red colour formed. To the mix was added now 0.5 g of sodium perchlorate
and a orange red precipitate formed immediately. After 5 minutes stirring and ultrasonic
treatment the precipitate was isolated by filtration and dried in vacuo at 50°C. In
this way 350 mg of an orange red powder was obtained in 70% yield showing the following
analytical characteristics:
1H NMR (400 MHz, CD
3CN): δ (ppm) 2.15, (CH
3CN), 2.28 (s, 3H, CH
3), 4.2 (ab, 4H, CH
2), 7.05 (d, 2H, pyridine), 7.38 (m, 4H, pyridine), 7.71 (2t, 4H pyridine), 7.98 (t,
2H, pyridine), 8.96 (d, 2H pyridine), 9.06 (m, 2H, pyridine).
UV/Vis (acetonitrile) [λmax, nm (ε, M
-1 cm
-1)]: 381 (8400), 458 nm (6400).
Anal.Calcd for C
25H
26Cl
2FeN
6O
8: C, 46.11; H, 3.87; N, 12.41; Cl, 10.47; Fe, 8.25. Found: C, 45.49; H, 3.95; N, 12.5;
Cl, 10.7; Fe, 8.12.
Mass-ESP (cone voltage 17V in CH
3CN): m/z 218.6 [MeN
4PyFe]
2+ ; 239.1 [MeN
4PyFeCH
3CN]
2+.
Example 2
Preparation of BzN4Py ligand
[0072] To 1 g of the N
4Py ligand prepared as described above, 20 ml of dry tetrahydrofuran freshly distilled
from LiAlH
4, was added under argon. The mixture was stirred and cooled to -70 °C by an alcohol
/ dry ice bath. Now 2 ml of 2.5 N butyllithium solution in hexane was added giving
an immediate dark red colour. The mix was allowed to warm to -20°C and now 0.4 ml
of benzyl bromidide was added. The mixture was allowed to warm up to 25 °C and stirring
was continued over night. Subsequently 0.5 g of ammonium chloride was added and the
mixture was evaporated in vacuo. To the residue water was added and the aqueous layer
was extracted with dichloromethane. The dichloromethane layer was dried on sodium
sulfate, filtered and evaporated giving 1 g brown oily residue. According to NMR spectroscopy,
the product was not pure but contained no starting material (N
4Py). The residue was used without further purification.
[0073] Subsequently [(BzN
4Py)Fe(CH
3CN)](ClO
4)
2, hereinafter referred to as Fe(BzN
4Py), was prepared as follows:
[0074] To a solution of 0.2 g of the residue obtained by the previous described procedure
in 10 ml of a mixture of 5 ml acetonitrile and 5 ml methanol was added 100 mg Fe(ClO
4)
2.6H
2O immediately a dark red colour formed. To the mix was added now 0.25 g of sodium
perchlorate and ethylacetate was allowed to diffuse into the mixture overnight. Some
red crystals were formed which were isolated by filtration and washed with methanol.
In this way 70 mg of a red powder was obtained showing the following analytical characteristics:
1H NMR (400 MHz, CD
3CN): δ (ppm) 2.12, (s, 3H, CH
3CN), 3.65 + 4.1 (ab, 4H, CH
2), 4.42 (s, 2H, CH
2-benzyl), 6.84 (d, 2H, pyridine), 7.35 (m, 4H, pyridine), 7.45 (m, 3 H, benzene) 7.65
(m, 4H benzene + pryidine), 8.08(m, 4H, pyridine), 8.95 (m, 4H pyridine).
UV/Vis (acetonitrile) [λmax, nm (ε, M
-1 cm
-1)]: 380 (7400), 458 nm (5500).
Mass-ESP (cone voltage 17V in CH3CN): m/z 256.4 [BzN
4Py]
2+; 612 [BzN
4PyFeClO
4]
+
Example 3
[0075] The bleaching activity of the Fe-catalysts prepared according to Example 1 and 2,
was demonstrated in the presence of hydrogen peroxide on standard tea-stained (BC-1)
cotton test cloths.
[0076] The experiments were carried out at 40°C and at a pH of 10 in a temperature-controlled
glass beaker equipped with a magnetic stirrer, thermocouple and a pH electrode.
[0077] Two pieces of test cloth were stirred for 30 minutes in 1 liter of a 8.6x10
-3 mol/l hydrogen peroxide solution in millipore water, containing concentrations of
the compounds as indicated in Table 1. After rinsing with demineralised water, the
test cloths were dried for 7 minutes in a microwave oven. The reflectance (R
460*) of the test cloths was measured on a Minolta® CM-3700d spectrophotometer including
UV-filter before and after treatment. The difference (ΔR
460*) between both reflectance values thus obtained gives a measure of the bleaching
performance, i.e. higher ΔR
460* values correspond to an improved bleaching performance.
TABLE 1
|
conc. Fe |
ΔR460* |
|
(mol/l) |
(at pH=10) |
blank |
- |
6.5 |
Fe(NO3)3 |
10x10-6 |
6.2 |
Fe(N4Py) |
10x10-6 |
12.0 |
Fe(MeN4Py) |
10x10-6 |
15.8 |
Fe(BzN4Py) |
10x10-6 |
17.3 |
[0078] In Table 1, Fe(MeN
4Py) and Fe(BzN
4Py) refer to the Fe-catalysts prepared according to Examples 1 and 2, and Fe(N
4Py) to the non-methylated analogue as described in WO-A-9534628, The blank and Fe(NO
3)
3 experiment were used as control.
[0079] These measurements show that significantly improved bleaching performance is obtained
with Fe(MeN
4Py) and Fe(BzN
4Py) as compared to Fe(N
4Py) as catalyst.
Example 4
[0080] The bleaching activity of the Fe(MeN
4Py) catalyst prepared according to Example 1 was demonstrated in the presence of a
detergent formulation on standard tea-stained (BC-1) cotton test cloths.
[0081] The detergent formulation contained the following ingredients and was dosed (in water)
as indicated in Table 2.
TABLE 2
Detergent formulation used for the bleaching experiments with Fe(MeN4Py) |
Ingredient |
Dosage (g/l) |
Sodium linear alkylbenzene sulphonate (LAS) |
0.60 |
Sodium triphosphate (STP) |
0.36 |
Sodium carbonate |
0.44 |
Sodium disilicate |
0.20 |
Sodium sulphate |
0.67 |
Sodium perborate monohydrate |
0.20 |
Tetraacetyleneethylene diamine (TAED) |
0.061) |
Fe(MeN4Py) |
<0.012) |
enzymes, fluorescer, SCMC, minors, moisture |
0.19 |
1) Only for experiment A |
2) Only for experiment B |
[0082] The experiments were carried out at 25°C and at a pH of around 10 (pH of the wash
liquor) by using water of 4 °F (Ca:Mg= 4:1) in a temperature-controlled glass beaker
equipped with a magnetic stirrer, thermocouple and a pH electrode.
[0083] Two pieces of test cloth were stirred for 30 minutes in 1 liter of the above detergent
formulation yielding
in situ:
* in experiment A: 1.5 x 10-3 mol/l hydrogen peroxide and 0.5 x 10-3 mol/l peroxyacetic acid; and
* in experiment B: 2 x 10-3 mol/l hydrogen peroxide containing 1 x 10-5 mol/l Fe(MeN4Py).
[0084] After rinsing with demineralised water, the test cloths were dried for 7 minutes
in a microwave oven. The reflectance (R
460*) of the test cloths was measured on a Minolta® CM-3700d spectrophotometer including
UV-filter before and after treatment. The difference (ΔR
460*) between both reflectance values thus obtained gives a measure of the bleaching
performance,
i.e. higher ΔR
460* values correspond to an improved bleaching performance.
Experiment A: 4.0 ΔR460* bleaching units
Experiment B: 6.7 ΔR460* bleaching units
[0085] These measurements show that significantly improved bleaching performance is obtained
with Fe(MeN
4Py)/H
2O
2 in representative detergent formulation, compared to peroxyacetic acid/H
2O
2 in the same detergent formulation.
Example 5
[0086] The dye oxidation activity of the Fe-catalysts prepared according to Examples 1 and
2 was demonstrated in the presence of hydrogen peroxide on a dye known as Acid Red
88.
[0087] The experiments were carried out at 40 °C at pH=10 in a 1 cm cuvet in the presence
of 8.6x10
-3 mol/l hydrogen peroxide and 6x10
-5 mol/l Acid Red 88. The absorbance at 503 nm (A
503), which is the maximum of the characteristic visible absorption of the dye in aqueous
media, was measured at t=0 and t=30 minutes. The ΔA
503 value given in the table is a measure of the dye bleaching activity: ΔA
503= 1 - (A
503(t=30)/A
503(t=0 min)), expressed in %.
[0088] A higher ΔA
503 value represent a better dye bleaching activity.
TABLE 3
|
|
pH 10 |
pH 8 |
|
conc.(mol/l) |
ΔA503 |
ΔA503 |
blank |
- |
15% |
2 % |
Fe(NO3)3. |
5x10-6 |
16 % |
2 % |
Fe(MeN4Py) |
5x10-6 |
26 % |
79 % |
Fe(BzN4Py) |
5x10-6 |
35 % |
86 % |
[0089] Fe(MeN
4Py) and Fe(BzN
4Py) in Table 2 refer to the Fe-catalyst prepared according to Examples 1 and 2. The
blank and Fe(NO
3)
3 experiment were used as controls.
[0090] These measurements show that improved dye oxidation performance is obtained when
Fe(MeN
4Py) and Fe(BzN
4Py) are used as catalysts, especially at pH 8.
Example 6
[0091] The oxidation activity of Fe(MeN
4Py) catalyst, prepared according to example 1, was demonstrated in the presence of
hydrogen peroxide on a range of organic substrates. The experiments were carried out
at ambient temperature in acetone. The concentration of the Fe catalyst was 7.7x10
-4 M and the ratio catalyst/H
2O
2/substrate was 1/100/1000. The turnover numbers indicated in Table 4 represent the
number of molecules formed per molecule of catalyst as determined after the indicated
time of the reaction by using gas chromatography. In a blank experiment or in the
presence of Fe(NO
3)
3, essentially no oxidation products could be detected.
TABLE 4
substrate |
product (turnover number) |
reaction time |
|
2-cyclohexen-1-ol (9) |
|
cyclohexene |
2-cyclohexen-1-one (3) |
30 minutes |
|
cyclohexene epoxide (0) |
|
|
cyclohexane |
cyclohexanol (11) |
30 minutes |
|
cyclohexanone (6) |
|
1. A bleach and oxidation catalyst comprising an Fe-complex having formula (A):
[LFeX
n]
zY
q (A)
or precursors thereof, in which
Fe is iron in the II, III,IV or V oxidation state;
X represents a co-ordinating species such as H2O, ROH, NR3, RCN, OH-, OOH-, RS-, RO-, RCOO-, OCN-, SCN-, N3-, CN-, F-, Cl-, Br-, I-, O2-, NO3-, NO2-, SO42-, SO32-, PO43- or aromatic N donors such as pyridines, pyrazines, pyrazoles, imidazoles, benzimidazoles,
pyrimidines, triazoles and thiazoles with R being H, optionally substituted alkyl
or optionally substituted aryl;
n is an integer number ranging from 0-3;
Y is a counter ion, the type of which is dependent on the charge of the complex;
z denotes the charge of the complex and is an integer which can be positive, zero
or negative; if z is positive, Y is an anion such as F-, Cl-, Br-, I-, NO3-, BPh4-, ClO4-, BF4-, PF6-, RSO3-, RSO4-, SO42-, CF3SO3- or RCOO-; if z is negative, Y is a common cation such as an alkali metal, alkaline earth metal
or (alkyl)ammonium cation;
q = z/[charge Y];
L represents a ligand of general formula (B)

which contains at least five nitrogen atoms and in which the substituent groups R1-R5 are selected from hydrogen, hydroxy, halogen, nitroso, formyl, carboxyl, and esters
and salts thereof, carbamoyl, sulfo, and esters and salts hereof, sulfamoyl, nitro,
amino, C0-C20-alkyl-hydroxy, C0-C20-alkyl-halogen, C0-C20-alkyl-nitroso, C0-C20-alkyl-formyl, C0-C20-alkyl-carboxyl, and esters and salts thereof, C0-C20-alkyl-carbamoyl, C0-C20-alkyl-sulfo, and esters and salts hereof, C0-C20-alkyl-sulfamoyl, C0-C20-alkyl-amino, C0-C20-alkylaryl, C0-C20-alkylheteroaryl, C0-C20 alkyl, C0-C8 alkoxy, carbonyl-C0-C6-alkoxy, and aryl-C0-C6-alkyl,
provided that R1 does not represent hydrogen.
2. Catalyst according to Claim 1, wherein L represents a ligand of general formula (B)
in which the substituents R2, R3, R4, R5 are independently selected from C0-C5 alkyl substituted with a nitrogen-containing heterocyclic aromatic group, such as
pyridines, pyrazines, pyrazoles, imidazoles, benzimidazoles, thiazoles, triazoles
and pyrimidines, or combinations thereof.
3. Catalyst according to Claim 2, wherein L represents a ligand of general formula (B)
in which the substituent group R1 represents C0-C20-alkylaryl, C0-C20-alkylheteroaryl, or C0-C20 alkyl.
4. Catalyst according to Claim 3, wherein L represents a ligand of general formula (B)
in which the substituents groups R2, R3, R4, R5 are independently chosen from C0-C5 alkyl substituted with a pyridine ring.
5. Catalyst according to any of Claims 1-4, wherein X represents a co-ordinating species
selected from CH3CN, pyridine, H2O, Cl-, OOH- and OR- wherein R is hydrogen, optionally substituted phenyl, naphthyl, or C1-C4 alkyl.
6. Catalyst according to any of Claims 1-5, wherein the counter ion Y is selected from
RCOO-, BPh4-, F-, Cl-, Br-, I-, ClO4-, BF4-, PF6-, RSO3-, RSO4-, SO42- and NO3-, wherein R=H, optionally substituted phenyl, naphthyl or C1-C4 alkyl.
7. Catalyst according to any of Claims 1-6, wherein the ligand L is N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane.
8. Catalyst according to any of Claims 1-6, wherein the ligand L is N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-2-phenyl-1-aminoethane.
9. A bleaching composition comprising a peroxy bleaching compound and a catalyst according
to any of the preceding claims.
10. Composition according to claim 9, which comprises said peroxy bleaching compound at
a level of from 2 to 35% by weight and said catalyst at a level corresponding to an
iron content of from 0.0005 to 0.5% by weight.
11. Composition according to claim 9 or 10, wherein the peroxy bleaching compound is selected
from hydrogen peroxide, hydrogen peroxide-liberating or generating compounds, peroxyacids
and their salts, and mixtures thereof, optionally together with peroxyacid bleach
precursors.
12. Composition according to any of claims 9-11, which further comprises a surface-active
material, in an amount of from 10 to 50% by weight, and a detergency builder in an
amount of from 5 to 80% by weight.