The bleaching catalyst combination contains (i) a transition metal complex with at least one nitrogen- containing ligand and (ii) an imine compound. The invention also provides selected bleaching catalyst combinations, a special metal complex contained in them, and bleaching agent compositions containing bleaching catalyst combinations.

Inorganic peroxy compounds, in particular hydrogen peroxide and compounds releasing hydrogen peroxide such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate have been used for a long time as oxidising agents in bleaching, washing and cleaning processes. A sufficiently fast bleaching of soiled textiles requires a temperature of at least 80°C.

The oxidation action of the inorganic peroxy compounds can be improved at low temperatures by the co-use of so-called bleaching activators. These bleaching activators are in particular N-acyl and 0-acyl compounds, for example multiply acylated alkylenediamines such as tetraacetyl- ethylenediamine (TAED), acetylated glycoluriles, N- acetylated hydantoins, diketopiperazines, carboxylic acid anhydrides, carboxylic acid esters, such as in particular sodium nonanoyloxybenzenesulfonate (NOBS) and acylated sugar derivatives.

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

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

For example, reference may be made to the complexes described in the following documents: EP 0 544 490, WO 98/54282, WO 00/12808, WO 00/60043, WO 00/52124, EP 0 392 592, WO 99/64156 and WO 00/12667.

Although numerous different transition metal complexes are known for the intended use, some of them only partially satisfy the expectations placed on them.

For example, if the reactivity is too high there is the danger of discolouration of coloured textiles and, in extreme cases, oxidative damage of the fibres. In addition to this some complexes break down the peroxy compound without producing a bleaching effect, or are insufficiently resistant to hydrolysis or are susceptible to oxidation.

Although many individual substances and also combinations are known, there is no reliable way of finding a transition metal complex that is effective as a bleaching catalyst.

Another way of activating peroxy compounds for bleaching and cleaning purposes is based on the use of special imine compounds as activators.

Iminium salts for example are suitable, wherein the iminium group may also be a constituent of an heterocyclic or heteroaromatic monocyclic or bicyclic ring system.

Iminium salts, including in particular 3,4- dihydroisoquinolinium salts, which may also be zwitterionic, are known from US patent specifications 5,482, 515 and 5,576, 282. Further iminium salts as well as oxaziridinium salts are disclosed in international patent application WO 01/16110.

Sulfonimines according to US patent 5,041, 232 as well as sulfanimines according to WO 97/41199 are also known as bleaching activators, which are also termed bleaching boosters. However, in practice many bleaching boosters do not meet in every respect the expectations placed on them, and accordingly there is an interest in discovering further bleaching systems.

In the effort to achieve a further improvement in the bleaching effectiveness of peroxy compounds bleaching systems have also been discovered that contain, in addition to a peroxidic compound, also a metal complex effective as bleaching catalyst and in addition an imine compound, in particular an iminium salt. By way of example reference may be made to WO 96/40855, according to which a bleaching agent composition contains 1-60 wt. % of a peroxy compound, 0.01-10 wt. % of an imine, and 0.001-10 wt. % of a transition metal complex.

Although the aforementioned combinations consisting of a transition metal complex and an imine compound are satisfactory as regards their effectiveness for the bleaching activation, because of the need to broaden the property profile of the bleaching there is still a requirement for further bleaching activation systems.

The present invention aims to provide combinations of a transition metal complex and an imine compound with at least one nitrogen-containing multidentate ligand that are suitable for use as bleaching activators in washing, bleaching and cleaning processes for various substrates

with oxygen and/or a peroxy compound, in particular a compound that releases hydrogen peroxide.

The present invention thus first of all provides for the use of a bleaching catalyst combination defined in the claims.

The complex (i) contained in the bleaching catalyst combination to be used according to the invention has the following general formula: [HnMnXJ Yt where M denotes the metal atom, which in this connection may be Mn (II), Mn (III), Mn (IV), Fe (II), Fe (III), Co (II), Co (III), Cu (I) and Cu (II). In the preferred combinations the complex (i) is a cobalt complex. Since the complex is mononuclear or dinuclear, the index n denotes the number 1 or 2.

The ligand L is a nitrogen-containing organic multidentate ligand of the general formula (I). The index m denotes å whole number in the range 1 to 4, in particular 1 or 2.

X denotes a neutral or anionic ligand co-ordinating with M, preferably selected from the group comprising water, lower alcohols, in particular methanol, acetonitrile, hydroxide, alcoholate and halide, in particular chloride, NH3 and alkylamine, 02-, o22~. The index õ denotes zero or a whole number in the range from 1 to 4.

Y denotes a counterion, and the index t is a whole number such that the complex is neutral. Y, which is an anion or cation but is generally an anion, may also be a constituent of a functional substituent such as a carboxylate group of the nitrogen-containing ligand. Examples of Y include C1-, SO42-, CO32-, POg3, N03, HSO4, H 04, Na+, K+, Li+, Mg+, Cc Cool4-.

The ligand characterising the complex (i) has the general formula (I): The bridge member B of the ligand denotes a radical from the group comprising oxygen, sulfur ; NR5-, CH (NHR6) and a ketone hydrate group. The radicals R1, R2, R3 and R4 denote independently of one another a radical from the group comprising H, unsubstituted or substituted alkyl, aryl and heteroaryl radicals, or the structural elements R1-N=C-R2 and/or R3-N=C-R4 may denote a five-membered or six-membered optionally substituted ring.

The radicals R5 and R6 denote H, substituted or unsubstituted linear, branched or cyclic C1-C2o-alkyl radicals, which may also contain one or more heteroatoms.

Where the aforementioned radicals are substituted, the substituents are preferably from the group comprising hydroxyl, halogen, amino, acylamino, carbalkoxy, carboy, carboxamino and SO3H or SO3-.

Preferred complexes (i) contain as ligands compounds in which R1-N=C-R2 and R3-N=C-R4 denote a five-membered or six- membered heterocyclic or heteroaromatic ring. Examples are 1, 3-oxazolin-2-yl and 2-pyridyl. A particularly preferred bridge member B is the ketone hydrate structural element.

Transition metal complexes and their use for activating peroxy compounds, in which the complex contains at least one ligand of the general formula (I) are, except for the corresponding ketone hydrate compounds, known from EP 0 392 592, and accordingly this document is incorporated into the disclosure.

The bleaching agent catalyst combination to be used according to the invention contains as second component an imine compound (ii) that is selected from the group comprising iminium salts (II), oxaziridinium salts (III), sulfonimines (IV) and sulfanimines (V) of the general formulae (II) to (V):

Such imine compounds are known from the documents mentioned in the introduction. Accordingly, patent specifications US 5,482, 515, US 5,576, 282 and US 5,041, 232 as well as the international patent application WO 01/16110 are incorporated into the description.

Of the preferred imine compounds, particularly preferred are iminium salts in which R7 to R10 independently of one another denote a radical from the group comprising aryl, heteroaryl, alkyl, aralkyl, alkaryl, cycloalkyl, heterocycloalkyl and alkenyl, in which the radicals may be

substituted or unsubstituted and contain 1 to 30 C atoms.

The radicals R8 to R1° may also denote H. One or more groupings R9-C-Rl°, R9-C=N-R7 and R7-N-R8 may also denote a monocyclic or polycyclic, cycloaliphatic or heterocyclic aromatic or heteroaromatic ring system The bridge member Q denotes an oxygen bridge or the group NR. Y denotes an anionic counterion, which is preferably selected from the group comprising Cl', L-, Br-, Y-, HSO4-, SO42-, NO3-, PO43-, HPO42-, BF4-, ClO4-, formate, acetate and Co (Hal) 4-, where Hal denotes Cl-or Br-.

The combinations according to the invention, in particular those consisting of a transition metal complex with a ligand from the group comprising di (2-pyridyl) amine, di (2- pyridyl) ketone hydrate and N-alkyl-di (2-pyridyl)- methylamine and an imine compound from the group comprising iminium salts, in particular 3,4-dihydroisoquinolinium salts and imidazopyridinium salts, have a surprisingly good overall effect in the activation of inorganic peroxy compounds.

A combination of cobalt-bis [di (2-pyridyl) ketone hydrate] (= Co (DPKH) 2) of the formula: and 1, 3, 3-tris (2-pyridyl)-3H-imidazole l, 5-a] pyridin-4- iminium salt (=TPIP-salt), in particular in the form of the TPIP-CoCl4 salt of the formula:

have an unexpectedly good bleach-activating effect.

Preferably such a combination is used that contains as complex (i) Co (DPKH) 2 and as imine (ii) a TPIP salt, in particular a tetrachlorocobaltate. Such a combination can readily be obtained by oxidation of bis [di (2-pyridyl)- methyl] amine (=BDPMA) in the presence of oxygen and/or a peroxy compound and a cobalt salt-see C. Hemmert et al., Chem. Eur. J. (1999), 5 (6), 1766.

Depending on the oxidation time, the quantitative ratio of Co (DPKH) 2 and TPIP salt can easily be controlled, the formation of TPIP salt predominating at the start of the oxidation.

The bleaching catalyst combination to be used according to the invention can be employed in washing, bleaching and cleaning processes for the activation of oxygen and/or peroxy compounds.

The peroxy compounds include in particular hydrogen peroxide, inorganic salts releasing hydrogen peroxide such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate, as well as peroxycarboxylic acids with 1 to 18 C atoms and 1 or 2 peroxycarboxy groups. Examples are peroxyacetic acid, diperoxyglutaric acid, diperoxyadipic acid,

phthalimidopercaproic acid, diperoxylauric acid, diperoxydodecanedioic acid and peroxybenzoic acid.

The peroxycarboxylic acids may also be formed in situ in the washing, bleaching and cleaning processes from an N- acyl compound or an 0-acyl compound, as has already been mentioned in the introduction, in the presence of hydrogen peroxide or a compound releasing hydrogen peroxide.

The amount of a combination of a complex (i) and an imine compound (ii) to be used according to the invention may vary within wide limits, a total amount in the range from 5 to 10,000 ppm referred to the aqueous medium used in a washing, bleaching or cleaning process preferably being employed.

The amount used and the ratio of the two components (i) and (ii) is determined by the person skilled in the art by readily performable preliminary tests, having regard to the results desired by the person skilled in the art.

The combination to be used according to the invention consisting of a complex (i) and an imine compound (ii) may either be a constituent of a conventional detergent, bleaching agent or cleansing agent, or may be added directly to the aqueous medium of a wash, bleaching or cleaning liquor.

A bleaching agent composition according to the invention contains a peroxy compound and a bleaching catalyst combination according to the invention in an effective amount, such as 0. 01 to 50 wt. %, in particular 0.01 to 20 wt. %, referred to the peroxy compound.

Such washing, bleaching and cleaning agents or aqueous media containing them comprise, apart from the combination to be used according to the invention, also one or more peroxy compounds, normally one or more surface active components, inorganic builders such as in particular

zeolites, organic builders such as peroxycarboxylic acids, pH regulators and, if necessary, further auxiliary substances, for example activators (peracid precursors), enzymes, greying inhibitors and further auxiliary substances known to the person skilled in the art and performing specific functions.

Examples Preparation of the bleaching combination of Co (DPKH) 2 and TPIP salt The starting substance bis [di (2-pyridyl) methyl] amine was prepared according to Eur. J. Org. Chem. 1998,1271.

Reaction of BDPMA with cobalt salt : A solution of 0.70 g (2.81 mmole) of cobalt (II) acetate tetrahydrate in 20 ml of ethanol was added to 1.00 g (2.83 mmole) of BDPMA in 20 ml of acetonitrile. After the addition the solution was stirred for 5 days at room temperature. The solution was then covered with a layer of ethyl acetate and allowed to stand for 9 days in a closed flask. During this time further ethyl acetate was constantly carefully added until the first crystals had formed. In some cases no crystals separated out, in which case the solution was concentrated by evaporation to dryness. The product was dried in air. (Yield : 95%, dark red powder) HPLC-MS analysis (W-detection) showed that the powder was a mixture of the complex Co (DPKH2) and TPIP-CoCl4 salt.

Co (DPKH) 2 and TPIP salt can also be prepared independently of one another by methods known in the literature.

The effectiveness of combinations according to the invention was determined by means of a morin test as well as a wash test.

The complexes of Examples 2 and 3 as well as complexes prepared in a similar way or by processes known in the literature were investigated as regards their catalytic activity by means of the morin test and in some cases wash 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.

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

Wash test: ATLAS LAUNDER-O-METER laboratory washing machine Temperature: 30°C Wash time: 30 minutes Water hardness : 14°d Soiling: Tea, in some cases also grass stains on cotton Detergent formulation: 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 and iminium salt: in total 2400 ppm Detergent concentration : 5 g/1 The basic formulation plus percarbonate/TAED (VB1) always served as comparison. The change in reflection with respect to the initial fabrics is subtracted from the change in reflection that was achieved with percarbonate/TAED/bleaching catalyst combination (B1 and B2).

The test results are shown in the following table.

- No. Morin Test Wash Test A R Transmission [%] VB Without 4, 2% 6.7 (with combination respect to starting fabric) B1 Co (DPKH) 2 (96%) 91. 0% 5.7 (with TPIP (CoCl4) (4%) respect to VB 1) The test results show that the use of the catalyst combination according to the invention produces a very significant improvement in effectiveness.