Use of transition metal complexes with nitrogen-containing polydentate ligands as a bleaching catalyst and bleaching agent composition Description The invention relates to the use of transition metal complexes with nitrogen-containing polydentate ligands as a bleaching catalyst and to bleaching agent compositions comprising such a bleaching catalyst. The activity of peroxy compounds in washing, bleaching and cleaning processes at low temperature is increased by the transition metal complexes to be used according to the invention.

Inorganic peroxy compounds, in particular hydrogen peroxide and compounds which liberate hydrogen peroxide, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate, have been employed for a long times as oxidizing agents in bleaching, washing and cleaning processes. Sufficiently rapid bleaching of soiled textiles requires a temperature of at least 809C.

The oxidizing action of inorganic peroxygen compounds at reduced temperature can be improved by co-using so-called bleaching activators. Bleaching activators are, in particular, N-and 0-acyl compounds, for example polyacylated alkylenediamines, such as tetraacetylethylenediamine (TAED), acetylated glycolurils, N-acetylated hydantoins, diketopiperazines,'carboxylic acid anhydrides, carboxylic acid esters, such as, in particular, sodium nonanoyloxy-benzenesulfonate (NOBS), and acylated sugar derivatives.

By using a combination of a peroxy compound and an activator, bleaching can be carried out at about 60°C instead of above 80°C without a loss in activity.

In efforts to be able to carry out washing and bleaching below 60°C, the use of transition metal complexes, in particular complexes of manganese, iron, cobalt and copper with at least one polydentate organic ligand, in particular nitrogen-containing ligands, has been described in many documents.

Reference is made by way of example to the complexes described in the following documents: EP 0 544 490, WO 98/54282, WO 00/12808, WO 00/60-043, WO 00/52124, EP 0 392 592, WO 99/64156 and WO 00/12667.

Although numerous different transition metal complexes are thus known for the use aimed for, they only partly meet some of the expectations imposed on them.

Thus, if the reactivity is too high there is the risk of a change in colour of dyed textiles, and in the extreme case oxidative damage to the fibres. Furthermore, some complexes decompose the peroxygen compound without a bleaching action, are insufficiently stable to hydrolysis or are susceptible to oxidation.

The doctrine of WO 00/32731 is bleaching catalysts with di (2-pyridyl) methylamine organic nitrogen-containing ligand. This catalyst is suitable for increasing the oxidizing and bleaching action of hydrogen peroxide. A further increase is achieved by combination of such a bleaching catalyst with a so-called activator which can form a peroxycarboxylic acid in the presence of a source of hydrogen peroxide. As has been shown in practice, different property profiles of bleaching catalysts which the products known to date do not achieve in all points are required in washing, bleaching and cleaning compositions.

The international application WO 98/03263 discloses homogeneous oxidation catalysts, these being transition metal complexes with a macrocyclic ligand. The ligand

includes four donor atoms, such as nitrogen, usually in the form of amides, so that the ligand is a tetraamide. Further similar macrocyclic ligands and chelate complexes are the doctrine of WO 99/64156, where the ligand can contain-four amidic or also two aminic and two amidic nitrogen atoms.

Such ligands are indeed stable to oxidation, but the activity as a bleaching catalyst leaves something to be desired.

The object of the present invention is accordingly to provide further transition metal complexes with at least one nitrogen-containing polydentate ligand which are suitable as a bleaching catalyst for activation of a peroxy compound and preferably also oxygen.

It has been found that transition metal complexes with a transition metal from the series consisting of manganese, iron, cobalt or copper are very active and gentle bleaching catalysts if these contain at least one nitrogen-containing polydentate ligand of the general formula (I) according to the claims.

The invention thus provides the use of a transition metal complex with at least one nitrogen-containing polydentate ligand as a bleaching catalyst for activation of a peroxy compound or of oxygen, wherein the complex is mono-or polynuclear, the transition metal (M) is manganese, iron, cobalt or copper and the nitrogen- containing polydentate ligand (L), at least one of which is present, has the general formula (I)

wherein A represents either the group-NH-CO-R2 or the group the bridge member B is chosen from the series consisting of wherein R4 to R7 independently of one another represent a radical from the series consisting of H, arylalkyl, aryl, heteroaryl, wherein R4 with R5 or/and R6 with R7 or R4 with R6 together with the atom (s) carrying them can form a five- to seven-membered, in particular five-or six-membered cycloaliphatic or O- or N-heterocyclic ring, which can also contain a double bond, and wherein the structural elements of the general formulae (BO) to (B5) have a total of 2 to 20 C atoms, R8 and R9 independently of one another can represent a radical from the series consisting of H, methyl or together can represent carbonyl oxygen, R10 and R11 independently of one another can represent a radical from the series consisting of H, (Cl-C4) alkyl,

halogen or together can represent a fused-on aromatic ring and R12 can represent H or methyl, the radicals R1 and R2 independently of one another can represent a radical from the series consisting of-COOH, - CONH2,-CONHR13, C (CH3) 20H, 2-pyridyl, 1, 3-oxazolin-2-yl, imidazol-2-yl or R1-R2 together can represent the radical wherein R13 can be chosen from the series consisting of linear, branched or cyclic alkyl, aryl, heteroaryl, in particular 2-pyridyl, 1, 3-oxazolin-2-yl and imidazol-2- yl and heteroalkylmethyl, R14 can be chosen from the series consisting of substituted or unsubstituted, linear, branched or cyclic alkyl, benzyl, aryl, heteroaryl, heteroarylmethyl, and R3 represents a radical from the series consisting of alkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and Z represents H, alkyl, aryl, dialkylaminoethyl, heteroaryl, and in the case of the oximes R1 additionally can represent the radical

wherein n is 0 or 1, R15 H or alkyl, and the group R15-C-R15 can be cycloalkyl.

The subclaims relate to preferred embodiments of the use according. to the invention.

The present invention also provides the bleaching agent composition defined in the claims, which comprises a peroxy compound, in particular a source of hydrogen peroxide, and a transition metal complex to be used according to the invention in an amount effective for activation. The subclaims of the bleaching agent composition relate to preferred embodiments thereof.

The transition metal complex to be used according to the invention can be mono-or polynuclear and contains as the transition metal one from the series consisting of manganese in the valency level II to IV, iron in the valency level II or III, cobalt in the valency level II or III and copper in the valency level I or II. Depending on the number of heteroatoms capable of ligand formation and their steric alignment in the ligand L, the complex can contain one or more transition metal atoms, preferably one or two metal atoms of the same type. In general the complex has the general formula [LJXjYp

In this formula, L denotes the ligand to be used according to the invention, M denotes a transition metal atom from the abovementioned series, X denotes a coordinating neutral or mono-or polyvalent ligand for saturation of the ligand sphere and Y denotes a non-coordinating counter-ion, which can be anionic or, if the sum of anionic ligands X and ionic substituents in the ligand L exceeds the sum of the valency of the metal atoms M, can also be cationic. The index m represents an integer in the range from 1 to 4, in particular 1 or 2, the index n represents an integer, preferably 1 or 2, the index o represents zero or an integer in the range from 1 to 8 and the index p represents zero or an integer in order to achieve a complete charge compensation. Y can also be a substituent, such as carboxylate or sulfonate, in the ligand.

The polydentate ligand L to be used according to the invention has the structure according to the general formula (I) already shown. According to a preferred embodiment, the complexes are cobalt complexes with the ligand B (NH-CO-R1) 2, wherein, particularly preferably, B represents optionally substituted ortho-phenylene and/or represents a radical from the series consisting of COOH, CONHR', C (CH3) OH where R'is H, (Cl-C4)-alkyl or substituted alkyl and 2-pyridyl.

The bleaching activators to be used according to the invention can in some cases also be macrocyclic, but the ligands differ from the ligands according to WO 98/03263 and WO 99/64156 by at least one feature.

Ligands of preferred bleaching activators are open-chain, that is to say not macrocyclic. Several of these substances are more easily obtainable than the macrocyclic ligands which are already known. Surprisingly, the substances of sometimes simple structure with oxamic acid or oxamide structural elements show a surprisingly good bleaching- activating action. Apart from on the ligand structure and

on the metal atom of the complex, the action also depends in part on the coloured substance to be bleached.

A new genus of active transition metal complexes contain a chelate ligand with four nitrogen donor atoms, two of which have an amide structure and two N atoms of which are the constituent of an N-heterocyclic ring.

Finally, ligands with two amide groups and two oxime groups are interesting compounds for complexing of Mn, Fe, Co and Cu for the purpose of obtaining active bleaching activators.

The cyclic bridge members B can also have functional or non-functional substituents, for example OH, NH2, COOH, S03H, COOMe, S03Me, wherein Me represents an alkali metal, N+ (C1-C4-alkyl) 4, F, Cl, alkoxy, in particular (C1-C4) alkoxy, alkyl, in particular (C1-C4) alkyl, phenyl, benzyl, pyridyl, 2-pyridylmethyl.

The radicals R1 and R2 in the ligand L can be identical or different and represent H, linear, cyclic or branched alkyl or heteroalkyl, aryl, heteroaryl, arylalkyl and heteroarylalkyl. Examples are methyl, ethyl, i-propyl, tert-butyl, benzyl, phenyl, pyridyl, in particular 2- pyridyl, 1, 3-oxazolin-2-yl, 1, 3-oxazolin-2-methyl and 2- pyridylmethyl.

The radical R3 in the ligand L can be aryl, heteroaryl, alkoxy, aryloxy, heteroaryl, alkyl and arylalkyl. The examples mentioned above for R1 and R2 also apply here. If R3 represents alkoxy or aryloxy, it is preferably methoxy,

ethoxy, 2-hydroxyethoxy, 2-aminoethoxy, 2-N, N-di (C1- C4) alkylaminoethoxy and phenoxy.

Both the radicals R1 to R3 and bridge members (B1 to B5) can have one or more functional or non-functional substituents. These are those substituents such as have already been disclosed in connection with the description of the bridge member B. According to particularly preferred embodiments, the heterocyclic or heteroaromatic ring systems bonded to the bridge member B contain one or more linear or branched (C1-C4) alkyl groups, in particular methyl, isopropyl and tert-butyl, and furthermore phenyl, benzyl, 2-pyridylmethyl or-ethyl or 4-imidazolylmethyl or - ethyl.

According to a further preferred embodiment, one or more radicals from the series consisting of R1 to R15 or the nitrogen-containing ring systems formed therefrom contain hydrophilic substituents in order to increase the solubility of the complex. Examples of these are salt- forming functional substituents and hydroxyalkoxy groupings, which additionally can also contain one or more ether bridges.

The chemical name for some examples of suitable ligands and the formulae of some complexes containing them follow below: 5,8, 13, 16-tetrahydro-5,8, 13 ; 16-tetraaza- dibenzoCa, g] cyclododecene-6, 7,14, 15-tetraone (TTBP) 1,2-phenylene-bisoxamic acid (OPBA) Mn complex of 1, 2-phenylene-bisoxamic acid

N-methyl-N'- [2- (methylaminooxalylamino) phenyl] oxalamide (PBOMA) <BR> <BR> <BR> N- [4, 5-dichloro-2- (methylaminooxalylamino) phenyl]-NN- methyloxalamide (for R = Cl) N, N'-bis (pyridine-2-carboxamido)-1, 2-ethane (BPEN)

1, 2-bis (pyridine-2-carboxamido)-4, 5-dichlorobenzene (PCADB) 1, 2-bis (4-tert-butylpyridine-2-carboxamido)-4, 5- dichlorobenzene (for R = tBu)

N, N'-bis [2- (1-hydroxyiminoethyl) phenyl] - dimethylmalonodiamide N, N'-bis [2-(2-methyl-1-oxo-1-phenyl)propyl]- dimethylmalonodiamide

Apart from the ligand L, the catalyst can additionally contain coordinating co-ligands X. X here can be a mono-, di-or trivalent anion or a neutral molecule, which can be coordinated with the transition metal in a mono-, bi-or tridentate manner. The co-ligand is preferably the following groupings : OH-, OZ-, N03-, P043, CN, SCN-, HS04-, So42, Cl, Br, F, ClO4-, OCN-, HCO3-, RS-, CO32-, SO32-, RSO3-, S2O62-, RCO2 ; H20, ROH, CH3CN, NRR'R''.

The counter-ion Y of the complex to be used can be anionic or cationic, wherein the number p is chosen such that complete charge compensation is achieved. The counter-ion can preferably have the following meaning: F-, Cl, Br-, I-, NO3-, RS03 (R e. g. preferably CF3), ClO4-, RC02, PO43-,

Hop04, , H2PO4-, SO42-, HSO4-, CO32-, HCO3-, BF4-, PF6-, SO32-; Li+, Na, K, Mg, Ca, Ba.

The bleaching catalysts to be used according to the invention activate elemental oxygen and peroxy compounds.

Peroxy compounds are to be understood as meaning, in particular, hydrogen peroxide, compounds which liberate hydrogen peroxide, such as, in particular, sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate, perphosphates and persulfates, peroxycarboxylic acids and salts thereof and peroxycarboxylic acid bleaching precursors, so-called activators, and mixtures of such substances. Suitable peroxycarboxylic acids can be aliphatic or aromatic in nature and contain one or more peroxycarboxylic acid groups. Aliphatic peroxycarboxylic acids usually contain 1 to 20 C atoms, preferably 1 to 12 C atoms, and the particularly preferred peroxycarboxylic acid is peroxyacetic acid. Among the peroxycarboxylic acids with 2 peroxycarboxylic acid groups, those having 4 to 18 C atoms are preferred ; examples are diperoxyadipic acid, diperoxyazelaic acid, diperbxylauric acid and diperoxydodecanedioic acid, as well as salts of the acids mentioned, for example magnesium salts. Among the aromatic peroxycarboxylic acids there are, in particular, peroxybenzoic acid, m-chlorobenzoic acid, p- sulfonatoperoxybenzoic acid, diperoxyisophthalic acid, phthalimidopercaproic acid, 4, 4'-sulfonyl-diperoxybenzoic acid and magnesium salts of these acids.

The peroxycarboxylic acids can also be formed in situ under the use conditions, and in particular from so-called activators, which are in general 0-acyl compounds and N- acyl compounds. Such compounds form the corresponding

peroxycarboxylic acid under perhydrolysis conditions in the presence of hydrogen peroxide or a source of hydrogen peroxide. Activators which are particularly preferably to be used are: N, N, N'N'-tetraacetylethylenediamine (TAED), Na 1-methyl-2-benzoyloxybenzene-4-sulfonate, Na nonanoyloxybenzenesulfonate (NOBS), 2- (N, N, N- trimethylammonium) ethyl-sodium 4-sulfophenylcarbonate chloride (SPCC), pentaacetylglucose, phthalic anhydride.

For activation of peroxy compounds, the transition metal complexes to be used according to the invention are in general employed in an amount of about 0.0001 to 50 wt. %, in particular 0. 01 to 20 wt. % and particularly preferably 0.01 to 1 wt. %, based on the peroxy compounds.

Bleaching agent compositions according to the invention comprise at least one peroxy compound and a transition metal complex to be used according to the invention in an active amount. Such compositions expediently comprise 0. 001 to 50 wt. %, in particular 0.01 to 20 wt. % and particularly preferably 0. 01 to 1 wt. % of a transition metal complex with a ligand according to the invention, based on the content of peroxy compounds or precursor of one.

Bleaching agent compositions according to the invention expediently additionally comprise one or more surfactants from the series consisting of anionic, cationic, zwitter- ionic and nonionic surfactants, in particular surfactants such as are used in conventional washing, bleaching and cleaning compositions. Bleaching agent compositions according to the invention can furthermore also comprise organic and/or inorganic builders, such as zeolites.

Further constituents can be those such as are used in

conventional washing, bleaching and cleaning compositions, including enzymes, pH regulators and conventional alkali metal carriers, such as alkali metal silicate and alkali metal carbonates.

Examples Example 1: Preparation of the dibenzotetramide 5,8, 13, 16-tetrahydro- 5,8, 13,16-tetraaza-dibenzo [a, g] cyclododecene-6, 7,14, 15- tetraone (TTBP) Ligand: A solution of 5.52 g (17.9 mmol) diethyl 1,2- phenylene-dioxamate (preparation in accordance with: J. Am.

Chem. Soc. 1993, 115 (15), 6738) and 1.94 g (17.9 mmol) 1,2- phenylenediamine in 250 ml toluene was heated under reflux for 8 hours. The product was then filtered off and dried in vacuo at 50°C. Yield :. 29% (pale green solid).

M complex (M = Fe, Cu, Mn, Co): 500 mg (1.54 mmol) of ligand were dissolved in 50 ml THF under argon and the solution was then cooled to-100°C. 4.2 ml (6.17 mmol) n- butyllithium (15 per cent in pentane) were added all at once by means of a disposable syringe and, after 15 minutes, 195 mg (1.54 mmol) anhydrous iron (II) chloride 'were added. The reaction mixture was warmed to room temperature and stirred at this temperature for 22 hours.

Atmospheric oxygen was then passed through the solution in the course of 2 hours. The red-brown solid was filtered off and dried at 502C in vacuo. Yield : 96% Analogously, the Mn complex was prepared with anhydrous MnCl2 (42%, red-brown solid), the Cu complex with anhydrous CuCl2 (70%, dark brown solid) and the Co complex with anhydrous CoCl2 (83%, dark red solid).

Example 2: Preparation of N-methyl-N'- [2- (methylaminooxalylamino)- phenyl] oxalamide (PBOMA) N, N'-1, 2-Phenylene-bis (oxamic acid ethyl ester) 8.40 g (60.0 mmol) ethoxalyl chloride were added dropwise to a solution of 3.30 g (30.0 mmol) 1,2-phenylenediamine in 150 ml tetrahydrofuran analogously to the instructions in J. Am. Chem. Soc. 1993, 115 (15), 6738. The solution was heated under reflux for 0.5 hour and solid constituents were then filtered off. After distillation of the solvent, a little water was added to the oily residue, a colourless solid precipitating out. This was filtered off, washed with water and dried in vacuo. (Yield : 97%) Reaction of the diester with methylamine 8. 24 g (87.5 mmol) methylamine (33% in methanol) were added dropwise to a solution of 9.00 g (29.2 mmol) of the diethyl ester in 50 ml ethanol analogously to the instructions in J. Chem. Soc. Dalton Trans. 1997,745 at room temperature and the reaction solution was then stirred vigorously for 0.5 hour at 65°C. The colourless solid was filtered off, washed with a little cold methanol and methyl tert-butyl ether and dried in vacuo. (Yield: 82%) Co complex of PBOMA: 2.62 g (7.18 mmol) cobalt (II) perchlorate dihydrate, which were dissolved in a little methanol beforehand, were added to 2.00 g (7 lys mmol) of the bisamide PBOMA and 11.0 g (30.2 mmol) tetramethylammonium hydroxide in 10 ml methanol. A pale red solid precipitated out. This was filtered off and dried. (Yield: 84%)

Examples 3 to 8 The complexes of examples 1 and 2 and complexes prepared in an analogous manner or a manner known from the literature were investigated for their catalytic action by means of the Morin test and in some cases by means of a washing test.

Morin test: A sodium perborate monohydrate solution, a methanolic solution of tetraacetylethylenediamine and a dilute solution of the combination to be investigated are added to an aqueous Morin solution.

After intensive mixing, the extinction/transmission is measured at 400 nm after 30 minutes at 30°C. The blank value is measured in the absence of the combination to be investigated.

Washing test: Laboratory washing apparatus type ATLAS LAUNDER-0-METER Temperature: 30 °C Washing time: 30 minutes Water hardness: 14°d Staining : tea, in some cases also grass on cotton Detergent recipe: 12.2% anionic surfactant 7.7% nonionic surfactant 2.0% soap 34. 8% zeolite A 4.2% polycarboxylate 0.5% phosphonic acid 4. 1% corrosion inhibitor 1. 1% magnesium silicate

1.1% greying inhibitor (CMC) 2.2% sodium sulfate 4.1% sodium citrate Bleaching component: 17% sodium percarbonate 5% activator TAED Metal complex: 2,400 ppm Detergent concentration: 5 g/l As a comparison, the base recipe plus percarbonate/TAED, but without a metal complex (= catalyst) was always run (CE1). This change in reflection compared with the starting fabrics is subtracted from the change in reflection achieved with percarbonate/TAED/bleaching catalyst.

The results follow from the table: Table: Complex Morin test Washing test No. MLX or Y transmission (A R) 3 Co TTBP 94.8 0.2 4 Co PBOMA Y=N (CH3) 4+ 94. 8 1.9 5a Co OPBA 13 1.5 5b Cu OPBA 13.8 n. d. 5c Fe OPBA 5.8 n. d. X= (µO) 2 6 Mn OPBA 4.2 n.d. Y=(Na+)4 7 Mn BPEN 8 n.d. X=(Cl-) 2 8a Co PCADB. 6.2 n. d. X=(Cl-)2 8b Fe PCADB 46 n.d. Y=(Na+)4

The test results show that the catalysts according to the invention, in particular cobalt complexes, lead to a high increase in the activity of the peroxyacetic acid formed in situ from an activator (TAED) and perborate.