WO2003014280A1

WO2003014280A1 - Bleaching compositions

Info

Publication number: WO2003014280A1
Application number: PCT/EP2002/008538
Authority: WO
Inventors: Peter Leslie Gratton; John Oakes
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 2001-08-02
Filing date: 2002-07-30
Publication date: 2003-02-20
Also published as: WO2003014280A8; GB0118934D0

Abstract

Bleaching compositions which can be used in laundry processes comprising a metal-complexed ligand which preferably has the structure (I) wherein: B1, B2, B3 and B4 each represent a bridging group, M is a transition metal ion, L is an axial ligand, and Q is an alkali metal counter-ion. The compositions also comprise one or more enhancer compounds for the said metal complexing ligand, said enhancer compound being preferably of the general formula (II) wherein Z1-Z2 are electron-withdrawing groups, and Z3 and Z4 are hydrogen, or are absent when the bonding between Z1 or Z2 and the adjacent nitrogen in the general form is a pi-bond. The composition comprises optional surfactant, peroxygen source and builder.

Description

BLEACHING COMPOSITIONS

Field of the Invention;

The present invention relates to the use of certain macrocyclic metal -ligand complexes as catalytic bleaching agents. The invention will be particularly described with reference to bleaching in the context of fabric washing and laundry, although other and broader aspects of the invention are not intended to be excluded.

Background of the Invention;

It is well known that enzymes can engage in catalytic oxidation reactions. It is also known that certain compounds can facilitate the progress of these reactions. O-A-94/12619, WO-A-94/12620 and O-A-94/12621 (Novo Nordisk) disclose the use of simple substituted phenols, benzidine derivatives, phenothiazine derivatives and azino compounds as 'enhancers' for peroxidases and/or laccases. O-A-97/06244 (Ciba) also discloses various enhancers, such as substituted naphthols, barbituric acids, and substituted coumarins .

Oxidation catalysts comprising non-enzyme (i.e. non-peptide) metal -complexes are also known. Such catalysts have been used in laundry compositions as components of a bleaching system. They have also been used in other chemical processes such as in the pulp and paper industry and in the cleaning of hard surfaces. These catalysts generally activate H₂O₂ or other peroxygen sources in water, and are effective at neutral to basic pH, Some of these catalysts are even effective with oxygen itself as the source of oxidising equivalents.

A specific bleaching catalyst is disclosed in WO 98/03263, filed 21 July 1997, (Collins) . This comprises a macrocyclic (tetra) amido N-donor. The macrocycle is capable of complexing with a metal ion, for example an iron III or IV. United States Patent 5,853,428, filed 24 Feb 1997, (Collins) discloses use of similar catalysts in laundry detergent compositions .

Although they have other uses, non-enzyme bleaching catalysts are of particular utility in the prevention of so- called 'dye transfer' in a laundry process. This occurs when dyestuffs are released from one region of a cloth article during laundering and are later re-adsorbed at another location or on another article. It is advantageous to bleach the dyestuff while it is in aqueous solution, thereby preventing or reducing its transfer.

While the present invention is described herein with specific reference to laundry processes other uses of the materials disclosed herein are not intended to be excluded. Thus the word 'dyestuff should be interpreted in the general sense of a material giving an unwanted colour. Summary of the Invention;

We have now determined that the bleaching activity of the metal-ligand catalysts may be improved by the presence of enhancers .

Accordingly, a first aspect of the present invention provides a composition comprising:

a) a non-enzyme, metal -complexing ligand which is capable, in its complexed form and in the presence of a source of oxidising equivalents of oxidising dyestuffs and/or chromophoric soils, and,

b) one or more enhancer compounds.

Typically, compositions according to the present invention will comprise a ligand which is pre-complexed with a metal. While in some circumstances the conditions of use may be such that the environment is rich enough in a suitable metal, and the complex may form with sufficient ease to allow for metal-ligand formation in situ, it is preferable to provide the complex ab-initio.

Without wishing to be limited by any theory of operation, it is believed that the metal-ligand complex can form an activated species in the presence of oxidising equivalents. This activated species then interacts with the enhancer to form an activated species of enhancer. This activated species of enhancer can then interact with a dyestuff or another coloured material and bring about discolouration of that material .

Preferably the enhancers are nitrogen-containing organic molecules. More preferably, the enhancer compounds are of the general formula one, shown below:

General Formula One:

wherein Z₁-Z₂ are electron-withdrawing groups, independently selected from the group consisting of optionally substituted alkyl/ (hetero) (poly)aryl-, -sulfone, -sulfoxide, - sulfonate, -carbonyl, -oxalyl, -amidoxalyl, -hydrazidoxalyl , -carboxyl and esters and salts thereof, -amidyl, - hydrazidyl, and nitrile.

Z₃ and Z₄ are hydrogen, or are absent when the bonding between Z or Z₂ and the adjacent nitrogen in the general form is a pi-bond.

In preferred enhancers Z₃ and Z₄ are both hydrogen (thereby forming a hydrazino compound) , or Z₃ and Z₄ are both absent (thereby forming an azino compound) . Particularly preferred azino enhancers are molecules of the general formula given below:

This molecule is known as 2 , 2 ' -Azino-bis (3 -ethyl - benzthiazoline-6-sulphonate) diammonium salt. Its CA registry number is 30931-67-0.

Preferred hydrazino enhancers may contain one or more than one of the hydrazino structures. The general formulae of two particularly preferred enhancers are given below:

'Dimer'

The structure of a further enhancer, which does not have the characteristic azino- or hydrazino- bond of the preferred embodiments discussed above is given below:

This is phenothiazine-10-propionate (PTP) , as described in US-A-5 451 337 and US-A-5 445 755.

It is believed that there are several factors which contribute to the efficacy of the compositions disclosed herein. It is believed that the activated enhancer is a relatively long-lived species, that its low molecular weight (as compared with the metal-ligand complex) promotes diffusion of the activated enhancer and that it will be effective in heterogeneous environments. It is also believed that the activated enhancer is effective at low pH's.

The bleach catalyst per se may be selected from a wide range of transition metal complexes of organic molecules. Suitable organic molecules (ligands) for forming complexes and complexes thereof are found, for example in: GB 9906474.3; GB 9907714.1; GB 98309168.7, GB 98309169.5; GB 9027415.0 and GB 9907713.3; DE 19755493; EP 999050; WO-A-9534628; EP-A-458379; EP 0909809; United States Patent 4,728,455; WO-A-98/39098 ; WO-A-98/39406 , WO 9748787, WO 0029537; WO 0052124, and WO0060045 the complexes and organic molecule (ligand) precursors of which are herein incorporated by reference.

Preferred metal -complexed ligands are those having the structure as shown in general formula 2

General formula 2 :

Wherein: - Bi, B₃ and B₄ each represent a bridging group having zero, one two or three carbon containing nodes for substitution, and B₂ represents a bridging group having at least one carbon containing node for substitution, each said node containing a C (R) , C(Rχ) (R₂) or C (R) ₂ / each R substituent is the same is the same or different from the remaining R substituents, and

(i) is selected from the group consisting of alkyl, alkenyl, cycloalkyl, cycloalkenyl , aryl , alkynyl, alkylaryl, halogen, alkoxy, phenoxy and combinations thereof, or

(ii) form a substituted or unsubstituted benzene ring of which two carbons on the ring form nodes in the

B-unit ;

M is a transition metal ion;

- is an axial ligand; and,

Q is an alkali metal or tetra-alkyl ammonium or tetra- phenyl phosphonium counter-ion.

Preferably, the axial ligand is selected from the group consisting of water and halide. Particularly preferred axial ligands are water and chloride.

It is within the scope of the present invention to have a bleach activator, wherein M is selected from the group consisting of Fe, Mn, Cr, Cu, Co, Ni, Mo, V, Zn and W.

These complexes are of far lower molecular weight that enzymes and are consequently believed to be more weight efficient as regards activation of the enhancer. However, the complexes tend to be expensive to synthesise and consequently, their use in combination with a relatively inexpensive enhancer leads to a more cost effective system.

Detailed Description of the Invention;

Throughout the description and claims generic groups are used, for example alkyl, alkoxy, aryl etc. Unless otherwise specified the following are preferred group restrictions that may be applied to generic groups found within compounds disclosed herein:

alkyl : linear and branched Cl-C8-alkyl, preferably

C1-C6; alkenyl : C2-C8 -alkenyl, preferably C3-C6; cycloalkyl : C3-C8 -cycloalkyl, preferably C6-C8; cycloalkenyl C4- 12 -cycloalkenyl (preferably C4-C8) having a single cyclic ring or multiple condensed rings and at least one point of internal unsaturation which can be optionally substituted with from 1 to 3 Cl-C8-alkyl groups ; aryl : selected from homoaromatic compounds having a molecular weight under 300, preferably selected from group consisting of: phenyl ; biphenyl; naphthalenyl ; anthracenyl ; and phenanthrenyl ; alkynyl C2-C12 -alkynyl; alkylaryl : Cl-12-alkylaryl , wherein the aryl selected from homoaromatic compounds having a molecular weight under

300; halogen: selected from the group consisting of: F;

Cl; Br and I, preferably F and Cl ; and, alkoxy: Cl-C6-alkoxy, preferably C1-C4.

The present invention extends to fully formulated laundry products containing the catalysts and enhancers disclosed herein. Such products will generally contain a detergent active and will typically contain one or more builders together with the typical additives used in detergent compositions.

The present invention also extends to a packaged laundry treatment composition comprising a bleach activator as defined together with an enhancer as defined, and instructions for its use.

Typically, compositions of the present invention will comprise a peroxygen source.

Further aspects of the present invention and preferred embodiments are described below.

Ligands :

As described above, a preferred ligand is that described with reference to general formula 2.

Particularly preferred ligands of general formula 2 have R methyl. B3 and B4 are preferably absent, the two related sides of the ring being derived from a 'classical' amino acid in which the amino group is located on the alpha- carbon. A preferred starting amino acid is 2 -amino iso- butyric acid. (H₂N-C (CH₃) ₂-COOH) .

The transition metal is preferably selected from groups VI, VII, VIII, IX, X and XI of the periodic table. More preferably the metal is selected from the group consisting of Fe, Mn, Cr, Cu, Co, Ni, Mo, V, Zn and W. Particularly preferably the metal is selected from the group comprising: Fe, Mn, Cu and Co. Iron is the most preferred metal.

Suitable counter ions are tetra-alkyl ammonium, tetra-phenyl phosphonium, K, Li or Na, most preferably lithium.

The most preferred catalyst is that in which the ligand is 5, 6-benzo-3, 8, 11, 13-tetraoxo-2 , 2 , 9, 9, 12, 12-hexamethyl-

1 , 4 , 7 , 10-tetraaza-cyclo-tridecane as shown below as the Fe form, the axial ligand 'L' is water or preferably chloride. The counter-ion 'Q' is preferably lithium. The ligand is also known as 3 , 4 , 8 , 9-tetrahydro-3 , 3 , 6 , 6 , 9, 9-hexa-methyl-lH- 1,4,8, ll-benzotetraazocyclotridecane-2, 5, 7, 10 (6H, 11H) tetrone .

The composition is preferably used in laundry wash liquor, preferably an aqueous wash liquor.

The amount of catalyst in the composition according to the present invention is sufficient to provide a concentration in the wash liquor of generally 0.005 μm to 100 μm, preferably from 0.025 μM to 50 μM, more preferably from 0.05 μM to 10 μM.

Peroxygen Source :

While some of the catalysts described above are capable of utilising atmospheric oxygen as the source of oxidising equivalents, it is greatly preferred that the compositions of the present invention are pre-formulated with a source of hydroperoxyl species. It is preferable that the composition contains a peroxygen bleach or a peroxy-based or -generating system. The peroxygen bleach is preferably a compound which is capable of yielding hydrogen peroxide in aqueous solution although it is possible to use more complex systems which involve peracids and/or peracid precursors.

Hydrogen peroxide sources are well known in the art. They include the inorganic peroxides, for example alkali metal peroxides, organic peroxides for example 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.

Typical levels of peroxygen source in fully formulated composition will range from 0.05-55 wt . % with 1-40 wt . % being particularly preferred and 1-25 wt . % being most particularly preferred.

Typical levels of peroxygen source (as hydrogen peroxide equivalents) in fully formulated composition will be such that the in-use concentration will range from 0.005mM to lOOmM with 0.025mM to 50mM being particularly preferred and 0.05mM to lOmM being most particularly preferred.

Preferred peroxygen sources include percarbonate and perborate .

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 .

Another suitable hydrogen peroxide generating system is a combination of a C₁-C₄ alkanol oxidase and a C₁-C₄ alkanol, especially a combination of methanol oxidase (MOX) and ethanol . Such combinations are disclosed in WO-A-9507972 , which is incorporated herein by reference.

Alkylhydroxy peroxides are another class of peroxy bleaching compounds. Examples of these materials include cumene hydroperoxide and t-butyl hydroperoxide.

Organic peroxyacids (also known as peracids) may also be suitable as components of the bleaching system. Such materials normally have the general formula:

Y-R—C—O-OH

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. Typical monoperoxy acids useful herein include, for example:

(i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-a-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.

Typical diperoxyacids useful herein include, for example:

(i) 1, 12-diperoxydodecanedioic acid (DPDA) ;

(ii) 1, 9-diperoxyazelaic acid;

(iii) diperoxybrassylic acid; diperoxysebacic acid and diperoxyisophthalic acid;

(iv) 2-decyldiperoxybutane-l, 4-dioic acid; and

(v) 4 , 4 ' -sulphonylbisperoxybenzoic acid.

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. Peroxyacid bleach precursors are also 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.

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-Nιo-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 .

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.

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. 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 hexanoyl-oxybenzene sulphonate (STHOBS) ; and the substituted cationic nitriles.

Of the peracid precursors, TAED and SNOBS are preferred. Hydrogen peroxide based bleaching systems according to the present invention are markedly preferred to peroxyacid based systems. Where present the precursors are typically used in an amount of up to 12%, more preferably from 0.5 - 5% by weight of the composition.

DTI Polymers :

It is advantageous for the compositions of the invention to comprise one or more dye transfer inhibition (DTI) agents. Known agents include peroxidases, pthalocyanines and polymers.

Nitrogen-containing, dye binding, DTI polymers are preferred. Of these polymers and co-polymers of cyclic amines such as vinyl pyrrolidone, and/or vinyl imidazole are preferred. Suitable polymers include polyvinyl pyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, and polymers of N-carboxymethyl-4-vinylpyridinium chloride .

Polyamine N-oxide polymers suitable for use herein contain units having the following structural formula: R-Aχ-P; wherein P is a polymerizable unit to which an N-O group can be attached or the N-0 group can form part of the polymerizable unit; A is one of the following structures: - NC(O)-, -C(0)0-, -S-, -0-, -N=; x is 0 or 1; and R is an aliphatic, ethoxylated aliphatic, aromatic, heterocyclic or alicyclic group or combination thereof to which the nitrogen of the N-0 group can be attached or the N-0 group is part of these groups, or the N-0 group can be attached to both units. Preferred polyamine N-oxides are those wherein R is a heterocyclic group such as pyridine, pyrrole, imidazole, pyrrolidine, piperidine and derivatives thereof. The N-0 group can be represented by the following general structures: N(O) (R')₀-₃ , or =N(0) (R') ₀-ι , wherein each R' independently represents an aliphatic, aromatic, heterocyclic or alicylic group or combination thereof; and the nitrogen of the N-0 group can be attached or form part of any of the aforementioned groups. The amine oxide unit of the polyamine N-oxides has a pKa<10, preferably pKa<7 , more preferably pKa<6.

Any polymer backbone can be used provided the amine oxide polymer formed is water-soluble and has dye transfer inhibiting properties. Examples of suitable polymeric backbones are polyvinyls, polyalkylenes, polyesters, polyethers, polyamides, polyimides, polyacrylates and mixtures thereof. These polymers include random or block copolymers where one monomer type is an amine N-oxide and the other monomer type is an N-oxide. The amine N-oxide polymers typically have a ratio of amine to the amine N-oxide of 10:1 to 1:1,000,000. However, the number of amine oxide groups present in the polyamine oxide polymer can be varied by appropriate copolymerization or by an appropriate degree of N-oxidation. The polyamine oxides can be obtained in almost any degree of polymerization. Typically, the average molecular weight is within the range of 500 to 1,000,000; more preferably 1,000 to 500,000; most preferably 5,000 to 100,000. This preferred class of materials is referred to herein as "PVNO" . A preferred polyamine N-oxide is poly (4-vinylpyridine-N-oxide) which as an average molecular weight of about 50,000 and an amine to amine N-oxide ratio of about 1:4.

Block or random copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (as a class, referred to as "PVP/PVI") are also preferred. Preferably the PVP/PVI has an average molecular weight range from 5,000 to 1,000,000, more preferably from 5,000 to 200,000, and most preferably from 10,000 to 20,000, as determined by light scattering as described in Barth, et al . , Chemical Analysis, Vol. 113. "Modern Methods of Polymer Characterization"). The preferred PVP/PVI copolymers typically have a molar ratio of N-vinylimidazole to N-vinylpyrrolidone from 1:1 to 0.2:1, more preferably from 0.8:1 to 0.3:1, most preferably from 0.6:1 to 0.4:1. These copolymers can be either linear or

(TM) branched. Suitable PVP/PVI polymers include Sokalan HP56, available commercially from BASF, Ludwigshafen, Germany.

Also preferred as dye transfer inhibition agents are polyvinylpyrrolidone polymers ("PVP") having an average molecular weight of from about 5,000 to about 400,000, preferably from about 5,000 to about 200,000, and more preferably from about 5,000 to about 50,000. PVP ' s are disclosed for example in EP-A-262,897 and EP-A-256, 696.

(TM) Suitable PVP polymers include Sokalan HP50, available commercially from BASF. Compositions containing PVP can also contain polyethylene glycol ("PEG") having an average molecular weight from about 500 to about 100,000, preferably from about 1,000 to about 10,000. Preferably, the ratio of PEG to PVP on a ppm basis delivered in wash solutions is from about 2:1 to about 50:1, and more preferably from about 3:1 to about 10:1.

Also suitable as dye transfer inhibiting agents are those from the class of modified polyethyleneimine polymers, as disclosed for example in WO-A-0005334. These modified polyethyleneimine polymers are water-soluble or dispersible, modified polyamines . Modified polyamines are further disclosed in US-A-4 , 548 , 744 ; US-A-4 , 597 , 898 ; US-A- 4,877,896; US-A- 4,891, 160; US-A- 4,976,879;

US-A-5, 415, 807; GB-A-1 , 537 , 288 ; GB-A-1 , 498 , 520 ;

DE-A-28 29022; and JP-A-06313271.

Preferably the bleaching composition according to the present invention comprises a dye transfer inhibition agent selected from poly vinyl -pyrridine N-oxide (PVPy-NO) , polyvinyl pyrrolidone (PVP), polyvinyl imidazole, N-vinylpyrrolidone and N-vinylimidazole copolymers (PVP/PVI), copolymers thereof, and mixtures thereof.

The amount of dye transfer inhibition agent in the composition according to the present invention will be from 0.01 to 10 %, preferably from 0.02 to 5 %, more preferably from 0.03 to 2 %, by weight of the composition.

Surfactants and Builders :

The present invention has particular application in detergent bleaching, especially for laundry cleaning.

Accordingly, the composition preferably contains a surface- active material, optionally together with detergency builder.

The composition may contain a surface-active material in an amount, for example, of from 10 to 50% by weight.

The surface-active material may comprise materials which are 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. Typical synthetic anionic surface-actives are usually water- soluble alkali metal salts of organic sulphates and sulphonates having alkyl groups containing from about 8 to about 22 carbon atoms, the term "alkyl" being used to include the alkyl portion of higher aryl groups.

Examples of suitable synthetic anionic detergent compounds are sodium and ammonium alkyl sulphates, especially those obtained by sulphating higher (Cβ-Ciβ) alcohols produced, for example, from tallow or coconut oil; sodium and ammonium alkyl (C₉-C₂₀) benzene sulphonates, particularly sodium linear secondary alkyl (C₁₀-C₁₅) 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 (C₉-C₁₈) 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 reacting alpha- olefins (C₈-C₂₀) with sodium bisulphite and those derived by reacting paraffins with SO₂ and CI₂ and then hydrolysing with a base to produce a random sulphonate; sodium and ammonium (C₇-C₁₂) dialkyl sulphosuccinates; and olefin sulphonates, which term is used to describe material made by reacting olefins, particularly (C₁₀-C₂₀) alpha-olefins, with SO₃ and then neutralising and hydrolysing the reaction product . The preferred anionic detergent compounds are sodium (C₁₀-C₁₅) alkylbenzene sulphonates (C10-C15 LAS) , and sodium (Ci₆-Cιβ) alkyl ether sulphates (C16-C18 LES) .

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 (C₆-C₂₂) phenols, generally 5-25 EO, i.e. 5-25 units of ethylene oxides per molecule; and the condensation products of aliphatic (Cs-Cis) 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 .

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.

The composition will preferably comprise from 1 to 15 % wt of anionic surfactant and from 10 to 40 % by weight of nonionic surfactant . Preferred embodiments of the present invention comprise a mixed active system which comprises both anionic and nonionic surfactants. It is believed that the catalysts become less effective as the level of nonionic approaches 100% on surfactant. Conversely, where nitrogen-containing, dye binding, DTI polymers are used, the effectiveness of these polymers is reduced at high levels of anionic surfactant .

It is preferable that the level of anionic surfactant (on total surfactant) ranges from 10-90%wt and that the level of nonionic ranges from 90-10%wt (on total surfactant). It is especially preferred to use 30-60%wt/surfactant of anionic surfactant selected from: LAS, PAS, soap and mixtures thereof, together with 70-40%wt/surfactant of ethoxylated alcohol nonionic surfactant .

In absence of DTI polymer which is sensitive to surfactants, the formulation can contain 100% Anionic surfactant.

The composition may also contain a detergency builder, for example in an amount of from about 5 to 80 % by weight, preferably from about 10 to 60 % by weight.

Builder materials may be selected from 1) 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 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.

Examples of precipitating builder materials include sodium orthophosphate and sodium carbonate .

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 known as zeolite P) , zeolite C, zeolite X, zeolite Y and also the zeolite P-type as described in EP-A-0 , 384 , 070.

In particular, the composition 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. 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 water-insoluble crystalline or amorphous aluminosilicate builder materials, 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. It is preferred that the composition contains not more than 5% by weight of a carbonate builder, expressed as sodium carbonate, more preferably not more than 2.5 % by weight to substantially nil, if the composition pH lies in the lower alkaline region of up to 10.

Apart from the components already mentioned, the composition 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; stabilisers, 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 .

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. 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/H₂O₂ 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. Other suitable transition metal sequestrants are known and can be chosen by those skilled in the art, for example aminocarboxylates, aminophosphonates, and polyfunctionally substituted aromatic chelating agents, as disclosed further in WO-A-98/39406. If present, the sequestrants are generally present in amounts of 0.001 to 15%, more preferably 0.01 to 3.0%, by weight of the composition.

The present invention may be conveniently embodied in a solid form of product, which includes both a powder or tablet form of product. Both of these forms may be homogeneous or non-homogeneous . For example tablets may comprise a plurality of discrete regions which include some ingredients only, while powders may comprise mixed granules of differing compositions.

Examples ;

In order that the invention may be further and better understood it will be described in detail with reference to following non-limiting examples. The catalyst referred to in the examples is the Fe complex of 3,4,8, 9-tetrahydro-3, 3,6,6,9, 9-hexamethyl-lH-l, 4 , 8, 11- benzotetraazocyclotri-decane -2,5,7,10 (6H,11H) tetrone, with lithium as the counter-ion and water as the axial ligand. This was synthesised in accordance with the method set out in our co-pending patent application GB 0020846.2.

The model detergent used in the examples was such that the wash liquor contained lg/L of a 50/50 mixture of LAS and the nonionic Synperonic A7 , lg/L of sodium tripolyphosphate, 0.4 g/L sodium carbonate and 20 microlitres of sequestrant (Dequest™ 2047) .

Washes were simulated in a shaker-bath or Rotawash Linitester™ at 40°C, using 30 minutes agitation in 100-200ml of wash liquor.

All fabrics were measured after washing on an ICS Texicon Spectraflash™ 500 which was calibrated using the following settings:

UV Excluded - (420nm cut-off) Specular included Large aperture

Each monitor was measured through one thickness of cloth with bleached, non- fluorescent mercerised white cotton sheeting as the reference standard. Each monitor was measured four times and the average of these four measurements was taken to be the value of that monitor. Reflectance values were taken and converted into delta E values by a computer software package which reported average delta E values according to the following equation:

z_vE = /(ΔL² + Δ-ϊ² + Δb²)

Example 1 ; Removal of Tomato Stains ;

Four replicates of 5cm square tomato-stained cotton cloths were washed in 100ml phosphate-built detergent liquor using a shaker bath at 40 C.

Where present, levels of additional components are: 50μM Enhancer, 500μM H202 , lμM catalyst.

Data as presented in Table 1 are averages of eight readings (2 per side, per cloth) . In this experiment, higher values of delta-E indicate that more of the stain has been removed from the cloth.

Table 1 shows that peroxide alone shows a very slight improvement over just detergent but has no significant effect on tomato stain, while the catalyst + H202 has significant stain removal benefits. It can be seen that, in particular, the enhancer ABTS greatly increases stain removal . Table 1: Delta-E Values for Tomato Stained Cloth

Example 2; Pick-up on white from Direct Green Dye:

One lOxlOcm Direct Green 26 dyed (fixed) cotton cloth and one 10x10 cm white cotton monitor cloth were washed together in 200ml liquor using a Rotawash (Linitester) . Data values (delta E) shown in table 2 are averages of 4 readings (2 per side, per monitor cloth) .

In this experiment the delta-E represents the amount of dye which has been transferred from the green cloth to the white monitor. Therefore, lower levels of delta-E are representative of better results.

Where present, levels of additional components are: 100μM ABTS, 500μM H202, lμM catalyst.

Results in Table 2 show that peroxide alone did nothing to prevent dye transfer. Addition of catalyst has an effect which is further improved by the presence of the enhancer. Table 2; Delta-E values Direct Green Pick-up

Example 3; ABTS - pH profile of tea stain bleaching:

One lOxlOcm tea stained monitor cloth (BC1 stained) was washed in 100ml detergent (lg/L 50/50 LAS/A7, lg/L sodium sulphate) 20μM EDTA. This was buffered in phosphate or borax. Washes were 30 min in a shaker-bath at 40°C.

Data values (Delta R, 460nm - nil fluorescence) are given in Table 3 below, these are averages of 4 readings, two per side. Where present, examples have 100μM ABTS, 1000μM H202 , lμM catalyst. As with Example 1 above the delta-E values are higher for those experiments in which more of staining is removed from the cloth.

Table 3 shows that addition of ABTS extends the pH profile to better bleaching at low pH. In the control experiments and those with either peroxide or peroxide plus enhancer, the bleaching performance falls off with decreasing pH. When the enhancer is present, the performance does not fall off so quickly at lower pH. Table 3; pH range of catalyst/enhancer:

Example 4; Bleaching on tea stains;

Two 10x10cm BC1 cloths were washed 200ml phosphate-built detergent liquor (lg/L 50/50 LAS/A7, lg/L STP, 0.4g/L

Na₂C0₃) containing 20μM Dequest, for 30 min in the Rotawash

(Linitester) at 40' C. Data values shown in table 4 (Delta E) and are averages of 4 readings (2 per side, per cloth) . Where present, additional components are 100μM ABTS, 500μM H202, lμM catalyst.

As with Example 1 above, the delta-R values are higher for those experiments in which more of staining is removed from the cloth. The results show that enhancers improve the performance of the catalyst under these conditions. Table 4: Delta-R Values for Tea Stained Cloth

Example 5; Pick-up on white from Direct Green Dye;

One lOxlOcm Direct Green 26 dyed (unfixed) cotton cloth and one 10x10 cm white cotton monitor cloth were washed together in a zeolite-built detergent liquor (lg/L 55/45 LAS/A7,

1.5g/L zeolite, 0.5g/L Na₂C0₃) 200ml liquor using a Rotawash

(Linitester) . Data values (delta E) shown in Table 5 are averages of 4 readings (2 per side, per monitor cloth) .

Where present, levels of additional components are: lOOμM PTP, lOOOμM H202, lμM catalyst.

Results in Table 5 show that peroxide alone did nothing to prevent dye transfer. Addition of catalyst has an effect which is further improved by the presence of the enhancer. Table 5; Delta-E values Direct Green Pick-up

Claims

L. A composition comprising:

a) a non-enzyme, metal -complexing ligand which is capable, in its complexed form and in the presence of a source of oxidising equivalents, of oxidising dyestuffs and/or chromophoric soils, and,

b) one or more enhancer compounds for the said metal complexing ligand.

2. Composition according to claim 1 wherein the enhancer compound is of the general formula shown below:

(general formula 1)

wherein:

a) Z₁-Z₂ are electron-withdrawing groups, independently selected from the group consisting of optionally substituted alkyl/ (hetero) (poly) aryl-, -sulfone, - sulfoxide, -sulfonate, -carbonyl, -oxalyl, - amidoxalyl, -hydrazidoxalyl, -carboxyl and esters and salts thereof, -amidyl, -hydrazidyl, and nitrile, and,

b) Z₃ and Z₄ are hydrogen, or are absent when the bonding between Zi or Z₂ and the adjacent nitrogen in the general form is a pi-bond.

3) Composition according to claim 2 wherein the enhancer compound has the formula:

4) Composition according to claim 2 wherein the enhancer compound has the formula:

5) Composition according to claim 2 wherein the enhancer compound has the formula:

6) Composition according to any preceding claim wherein the metal -complexed ligands are those having the structure:

wherein :

a) Bi, B₃ and B₄ each represent a bridging group having zero, one two or three carbon containing nodes for substitution, and B₂ represents a bridging group having at least one carbon containing node for substitution, each said node containing a C (R) , C(Rι) (R₂) or C(R)₂ ,

b) each R substituent is the same is the same or different from the remaining R substituents, and

1) is selected from the group consisting of alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, alkynyl, alkylaryl, halogen, alkoxy, phenoxy and combinations thereof, or

2) forms a substituted or unsubstituted benzene ring of which two carbons on the ring form nodes in the B-unit;

c) M is a transition metal ion;

d) L is an axial ligand; and,

e) Q is an alkali metal counter-ion.

7. Composition according to any one of claims 1-6, further comprising a peroxygen source.

8. Composition according to claim 7, wherein the peroxygen source is hydrogen peroxide or a precursor thereof .

9. Composition according to any one of claims 1-8, further comprising surfactant and builder.

0. A laundry bleaching composition comprising:

a) at least one surfactant,

b) at least one builder,

c) a metal -complexed ligand having the structure

wherein:

Bi, B₃ and B₄ each represent a bridging group having zero, one two or three carbon containing nodes for substitution, and B₂ represents a bridging group having at least one carbon containing node for substitution, each said node containing a C(R), C(Rι) (R2) or C (R) ₂ , 2) each R substituent is the same is the same or different from the remaining R substituents, and

a) is selected from the group consisting of alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, alkynyl, alkylaryl, halogen, alkoxy, phenoxy and combinations thereof, or

b) forms a substituted or unsubstituted benzene ring of which two carbons on the ring form nodes in the B-unit;

3) M is a transition metal ion;

4) L is an axial ligand; and,

5) Q is an alkali metal counter-ion.

d) a peroxygen source, and,

e) one or more enhancer compounds for the said metal complexing ligand, at least one said enhancer compound being of the general formula shown below:

(general formula 1)

wherein :

1) Z₁-Z₂ are electron-withdrawing groups, independently selected from the group consisting of optionally substituted alkyl/ (hetero) (poly) aryl-, -sulfone, -sulfoxide, -sulfonate, - carbonyl, -oxalyl, -amidoxalyl, -hydrazidoxalyl , - carboxyl and esters and salts thereof, -amidyl, - hydrazidyl, and nitrile, and,

2) Z₃ and Z₄ are hydrogen, or are absent when the bonding between Z or Z₂ and the adjacent nitrogen in the general form is a pi-bond.