ZA200405014B - Bleach catalyst enhancement. - Google Patents

Description

BLEACH CATALYST ENHANCEMENT

FIELD OF INVENTION

' The present invention relates to enhancing the activity of a bleaching catalyst.

BACKGROUND OF INVENTION

WO 93/19811 discloses the use of lipoxygenase, linoleic acid and metal complexes with ambient oxygen to degrade an environmental contaminant.

DK 0352/98 discloses a process for bleaching coloured stains, comprising contacting, in an aqueous solution, the : stain with a lipoxygenase enzyme, an unsaturated fatty acid and a transition metal ion.

The use of bleaching catalysts for stain removal has been developed over recent years. As with any cleaning product a more economical use of active components and effective stain bleaching profile is sought.

SUMMARY OF INVENTION

We have found that there is a synergetic interaction between a catalyst together with peroxide and an enzyme system for generating hydroperoxides.

The present invention provides a bleaching composition comprising an organic ligand which forms a complex with a s transition metal for bleaching a substrate with a peroxygen bleach or source thereof, and a peroxygen bleach or source thereof, together with an oxidizable precursor selected from the group consisting of: ’ (1) an unsaturated acid or alkali metal salt thereof; and ) (ii) a generating system for producing an unsaturated acid in situ in an aqueous medium, together with an enzyme for oxidising the oxidizable precursor to form a hydroperoxide in situ.

It is preferred that the bleaching composition comprises at least 3 % of a peroxygen bleach other than an alkyl hydroperoxide. :

In order to permit differentiation of components, within the context of the present invention as claimed, neither the organic ligand or transition metal complex thereof nor the enzyme system for generating hydroperoxides should be construed as a peroxygen bleach or source thereof. In addition, the organic ligand which forms a complex with a transition metal is additional and distinct from other components.

The bleaching composition of the present invention provides for the lipase hydrolysis of an unsaturated oil (triglyceride) to provide an unsaturated carboxylic acid (or soap formed therefrom) which is subsequently oxidized by a . lipoxygenase to form a hydroperoxide which together with a catalyst serves to bleach a stain. Alternatively, the ' bleaching composition comprises an unsaturated carboxylic acid (or soap formed therefrom) which obviates the lipase

- 3 = hydrolysis step described above. In some instances . unsaturated oils in a stain serve as a precursor for the lipoxygenase to provide a hydroperoxide intimate with the ) stain.

The greatest effect is provided by a bleaching composition comprising a catalyst, a lipase and a lipoxygenase together with metabolites or precursors thereof for the enzyme system (lipase and lipoxygenase).

The present invention extends to a commercial package comprising the bleaching composition according to the present invention together with instructions for its use.

Any suitable textile that is susceptible to bleaching or one that one might wish to subject to bleaching may be used.

Preferably the textile is a laundry fabric or garment.

In a preferred embodiment, the method according to the present invention is carried out on a laundry fabric using an aqueous treatment liquor. In particular, the treatment may be effected in a wash cycle for cleaning laundry. More preferably, the treatment is carried out in an aqueous detergent bleach wash liquid, preferably in a washing machine. , A unit dose as used herein is a particular amount of the bleaching composition used for a type of wash. The unit . dose may be in the form of a defined volume of powder, granules or tablet or unit dose detergent liquid.

- 4 =

DETAILED DESCRIPTION OF THE INVENTION

Bleach Catalyst

The bleach catalyst per se may be selected from a wide range ) of organic molecules (ligands) and complexes thereof.

Suitable organic molecules (ligands) and complexes for use with the present invention 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. The air bleaching catalysts as used herein should not be construed as an peroxyl-generating system, alone or in combination with other substrates, irrespective of how they bleaching action works.

Another example of a bleaching catalyst is a ligand or transition metal catalyst thereof of a ligand having the formula (I):

R1

R3 X R4 (I)

Nn RO AN ~N Ro Ne = wherein each R is independently selected from: hydrogen, ) hydroxyl, and Cl-Cé4-alkyl;

R1 and R2 are independently selected from:

- 5 =

Cl-C4-alkyl, ' C6-Cl0-aryl, and, . a group containing a heteroatom capable of coordinating to a transition metal, wherein at least one of Rl and R2 is the group containing the heteroatom;

R3 and R4 are independently selected from hydrogen, C1-C8 alkyl, Cl-C8-alkyl-O-Cl-C8-alkyl, Cl1-C8-alkyl-0-C6-Cl0-aryl,

C6~Cl0-aryl, Cl-C8-hydroxyalkyl, and =(CH2),C(O)ORS5 wherein R5 is Cl-C4-alkyl, n is from 0 to 4, and mixtures thereof; and, ¥ is selected from C=0, -[C(R6):]y~ wherein Y is from 0 to 3 each R6 is independently selected from hydrogen, hydroxyl,

Cl-Cd4-alkoxy and Cl-C4-alkyl.

It is preferred that the group containing the hetroatom is: a heterocycloalkyl: selected from the group consisting of: pyrrolinyl; pyrrolidinyl; morpholinyl; piperidinyl; piperazinyl; hexamethylene imine; 1, 4-piperazinyl; tetrahydrothiophenyl; tetrahydrofuranyl; tetrahydropyranyl; and oxazolidinyl, wherein the heterocycloalkyl may be connected to the ligand via any atom in the ring of the selected heterocycloalkyl, a -Cl-Cé6-alkyl-heterocycloalkyl, wherein the heterocycloalkyl of the -C1-Cé6-heterocycloalkyl is selected from the group consisting of: piperidinyl; piperidine; 1,4- piperazine, tetrahydrothiophene; tetrahydrofuran; . pyrrolidine; and tetrahydropyran, wherein the heterocycloalkyl may be connected to the —-Cl-C6-alkyl via ' any atom in the ring of the selected heterocycloalkyl, a -Cl-C6-alkyl-heteroaryl, wherein the heteroaryl of the - cl1-C6-alkylheteroaryl is selected from the group consisting of: pyridinyl; pyrimidinyl; pyrazinyl; triazolyl:; pyridazinyl; 1,3,5-triazinyl; quinolinyl; isoguinolinyl; ' quinoxalinyl; imidazolyl; pyrazolyl; benzimidazolyl; thiazolyl; oxazolidinyl; pyrrolyl; carbazolyl; indolyl; and ’ isoindolyl, wherein the heteroaryl may be connected to the -

Cl-Cé6-alkyl via any atom in the ring of the selected heteroaryl and the selected heteroaryl is optionally substituted by -Cl1-Cé-alkyl, a —-C0-Cé6-alkyl-phenol or thiophenol, a -C2-Cd4-alkyl-thiol, thioether or alcohol, a -C2-Cd-alkyl-amine, and a —-C2-C4d4-alkyl-carboxylate.

The ligand forms a complex with one or more transition metals, in the latter case for example as a dinuclear complex. Suitable transition metals include for example: manganese in oxidation states II-V, iron II-V, copper I-III, cobalt I-III, titanium II-IV, tungsten IV-VI, vanadium II-V and molybdenum II-VI.

The transition metal complex preferably is of the general formula (AI): [MaLiXn] Ym in which:

M represents a metal selected from Mn (II)-(III)-(IV)~- . (Vv), Cu(I)-(II)-(III), Fe (ID) - (III) -(IV)—-(V), Co(I)-(II)- (III), Ti(II)-(ITI)-(IV), V(II)-(III)-(IV)-(V), Mo (II) - ‘ (III)-(IV)~(V)-(VI) and W(IV)-(V)-(VI), preferably from

Fe (II1)-(III)-(1IV)-(V);

IL represents the ligand, or its protonated or ' deprotonated analogue; . X represents a coordinating species selected from any mono, bi or tri charged anions and any neutral molecules able to coordinate the metal in a mono, bi or tridentate manner;

Y represents any non-coordinated counter ion; a represents an integer from 1 to 10; k represents an integer from 1 to 10; n represents zero or an integer from 1 to 10; m represents zero or an integer from 1 to 20.

It is preferred that the organic molecule (ligand) or transition metal complex is present in the composition such that a unit dose provides at least 0.1 pM of the organic molecule or transition metal complex thereof.

The transition metal complex may be preformed or formed in situ. The organic substance (ligand) required has complexing qualities. The ligand may be present in the bleaching composition as a free ligand or the complex formed in situ, for example, in tap water used to wash cloths or stain.

Ligands have different binding constants for different transition metals and tap water usually contains many different transition metal ions. A transition metal complex may be used in the method of the present invention that is t not itself active in bleaching with atmospheric oxygen.

However, upon addition to tap water an active atmospheric ' oxygen bleaching solution is formed. Common transition metals found in tap water at a relatively high concentration are iron and manganese ions. A different transition metal complex may be formed in situ than found in the bleaching composition used. The formation of a particular type of ) transition metal complex other than the transition metal complex found in the bleaching composition is dependent on ) the binding constant for a particular transition metal, transition metal ions present tap water and the concentration of transition metal ions present in the tap water. In addition, not only may the ligand complex with transition metals present in the bleaching medium but with transition metals found in a stain; for example tomato oil stains have relatively high concentrations of transition metals present, in particular iron. Alternatively, the ligand may complex with manganese as found in tea stains.

However, it is preferred that the bleaching composition comprises a preformed iron transition metal catalyst.

Peroxygen Bleach or Source Thereof

The composition of the present invention uses a peroxyl species to bleach a substrate. The peroxy bleaching species 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. ’ *

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

J the composition of the invention usually will be within the range of about 1-35% by weight, preferably from 5-25% by weight. One skilled in the art will appreciate that these amounts may be reduced in the presence of a bleach precursor e.g., N,N,N'N'-tetraacetyl ethylene diamine (TAED).

Another suitable hydrogen peroxide generating system is a combination of a Cl-C4 alkanol oxidase and a Cl-C4 alkanol, especially a combination of methanol oxidase (MOX) and ethanol. Such combinations are disclosed in International

Application PCT/EP 94/03003 (Unilever), 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 may also be suitable as the peroxy bleaching compound. Such materials normally have the general formula:

I

0 Cc Y

SNS

. wherein R is an alkylene 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 0 ¢” No” " ° 0) 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-.alpha.-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: (iv) 1,12-diperoxydodecanedioic acid (DPDA) ; (v) 1,9-diperoxyazelaic acid; (vi) diperoxybrassilic acid; diperoxysebasic acid and diperoxyisophthalic acid; , (vii) 2-decyldiperoxybutane-1,4-diotic acid; and (viii) 4,4'-sulphonylbisperoxybenzoic acid.

Claims (20)

Claims:

1. A bleaching composition comprising an organic ligand which forms a complex with a transition metal for bleaching a substrate with a peroxygen bleach or source thereof, and a peroxygen bleach or source thereof, together with an oxidizable precursor selected from the group consisting of: : (1) an unsaturated acid or alkali metal salt thereof; and (11) a generating system for producing an unsaturated acid in situ in an aqueous medium, together with an enzyme for oxidising the oxidizable precursor to form a hydroperoxide in situ.

2. A bleaching composition according to claim 1, wherein the composition comprises 1-35% by weight sodium percarbonate.

3. A bleaching composition according to claim 1 for bleaching a substrate, wherein the generating system for producing an unsaturated acid in situ in an aqueous medium is derived from an oily stain, lipoxygenase and the organic ligand.

e 4. A bleaching composition according to claim 1, wherein : bleaching composition comprises fat which has a degree : of unsaturation.

5. A bleaching composition according to any preceding claim, wherein bleaching composition is substantially devoid of fat other than a fat which participates as a precursor for a lipase or a lipoxogenase.

6. A bleaching composition according any preceding claim, wherein the oxidizable precursor is selected from the following system (i) an enzyme for enzymatically hydrolysing a fat, (ii) and the fat.

7. A bleaching composition according to any preceding claim, wherein the enzyme for enzymatically hydrolysing a fat is a lipase selected from the group consisting of Lipolase, Lipolase ultra, LipoPrime, Lipex, Lipomax, Liposam, and lipase from Mucor Miehei.

8. A bleaching composition according to any preceding claim, wherein the generating system for producing an unsaturated acid in situ in an aqueous medium comprises lipoxygenase and a lipoxygenase metabolic system.

9. A bleaching composition according to claim 8, wherein the lipoxygenase metabolic system comprises a fat and lipase, said fat being metabolised to produce linoleate (linoleic acid) for producing (9Z,11E)-13S-13- hydroperoxyoctadec-9, 11-dienoate. »

10. A bleaching composition according to any preceding claim, wherein the bleaching composition is devoid of ) lipase.

11. A bleaching composition according to claims 1 to 10, wherein the bleaching composition comprises 5,000 - 1,000,000 Lipoxygenase Units per gram of detergent composition.

12. A bleaching composition according to claims 1 to 9, wherein the bleaching composition comprises 10 - 20,000 Lipase Units per gram of detergent composition.

13. A bleaching composition according to claim 8 or claim 9, wherein the ratio of lipase:lipoxygenase is in the weight ratio range from 1:10 to 10:1.

14. A bleaching composition according to any preceding claim, wherein the organic ligand is present in the formulation in the form of a preformed complex.

15. A bleaching composition according to any preceding claim, wherein the organic ligand is present in the formulation in the form of a free ligand.

16. A bleaching composition according to any preceding claim, wherein the bleaching composition comprises a surfactant.

17. A bleaching composition according to claim 16, wherein ” the surfactant is saturated.

18. A bleaching composition according to claim 16, wherein the surfactant is unsaturated.

19. A bleaching composition according to any preceding claim, wherein the bleaching composition comprises a builder.

20. A process for bleaching a stain comprising the steps of treating a textile with a bleaching composition comprising an organic ligand which forms a complex with a transition metal for bleaching a substrate with a peroxygen bleach or source thereof, together with an oxidizable precursor selected from the group consisting of: (i) an unsaturated acid or alkali metal salt thereof, and (ii) a generating system for producing an unsaturated acid in situ in an aqueous medium and an enzyme for oxidising the oxidizable precursor to form a hydroperoxide in situ. »