Bleach auxiliaries, their manufacture and use in bleach and laundry compositions

Claim 2

A bleach auxiliary for use in aqueous medium as a peroxygen bleach catalyst, the bleach auxiliary comprising a water-soluble complex of iron and a multi-dentate ligand-forming chelating agent, wherein, at pH 10, the complex has a bleach catalytic activity of at least 10% and the stability of the complex against hydrolytic and oxidative degradation to water-insoluble iron species is at least 75%.

Claim 3

An auxiliary according to Claim 1 wherein the stability of the complex is such that in an aqueous solution thereof at 95°C or less and pH 10 and containing a total of 5 ppm of iron and an equivalent level of chelating agent, the level of unchelated iron is less than 10 x Molar, where x = log 10 K so + 12, and K so = solubility product of ferric hydroxide.

Claim 4

An auxiliary according to Claim 1 or 2 characterized in that the complex additionally comprises one or more aquo, hydroxy or peroxy ligands.

Claim 5

An auxiliary according to any of Claims 1 to 3 characterized in that the multidentate ligand is coordinated to iron exclusively through oxygen or ring nitrogen atoms.

Claim 6

An auxiliary according to any of Claims 1 to 4 characterized in that the multidentate ligand comprises at least three coordinating groups including at least two hydroxy, alkoxy, phenoxy or enolate coordinating groups.

Claim 7

- An auxiliary according to any of Claims 1 to 5 characterized in that the chelating agent is a hydroxy carboxylic acid having the general formula I wherein R is CH 2 0H, CHO or C0 2 H, n is from 4 to 8 and m is from 3 to n, or a salt, lactone, ether, acid ester or boric ester thereof.

Claim 8

An auxiliary according to Claim 6 characterized in that the chelating agent is selected from D-glycero-D-gulo heptonic acid, D-glycero-D-idoheptonic acid, stereoisomers thereof, mixtures thereof, and salts, lactones, acid esters and boric esters thereof.

Claim 9

An auxiliary according to any of Claims 1 to 7 additionally comprising an aminopolyphosphonate selected from nitrilotri(methylenephosphonic acid), ethylenediamine tetra(methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), hexamethylenediaminetetra(methylenephosphonic acid) and water-soluble salts thereof, an aminopolycarboxylate selected from nitrilotriacetic acid, ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, l,2-diaminocyclohexane-N,N,N',N'-tetracetic acid, diethylenetriaminepentaacetic acid and water-soluble salts thereof, or a polyphosphate selected from the tripolyphosphates and the penta- and hexametaphosphates wherein the mole ratio of aminopolyphosphonate and/or aminopolycarboxylate and/or polyphosphate to iron complex is from 1:1 to 25:1.

Claim 10

- A bleach auxiliary suitable for use in aqueous medium as a peroxygen bleach catalyst, characterized by an iron complex consisting essentially of a water soluble, substantially non-colloidal complex of iron and a multi-dentate ligand forming chelating agent, the chelating agent being a hydroxycarboxylic acid having the general formula I wherein R is CH 2 0H, CHO or C0 2 H, n is from 4 to 8, m is from 3 to n, or a salt, lactone, ether, acid ester or boric ester thereof.

Claim 11

- A bleach auxiliary suitable for use in aqueous medium as a peroxygen bleach catalyst, characterized by an iron complex consisting essentially of a water soluble, substantially non-colloidal complex of iron and a multi-dentate ligand forming chelating agent, the chelating agent being a hydroxycarboxylic acid having the general formula I wherein R is CH 2 0H, CHO or C0 2 H, n is from 4 to 8, m is from 3 to n, or a salt, lactone, ether, acid ester or boric ester thereof.

Claim 12

An auxiliary according to any of claims 1 to 9 in particulate form wherein the iron complex is incorporated in a water-soluble or water-dispersible organic carrier having a melting point greater than about 30°C and/or in a water-soluble or water-dispersible agglomerated matrix of solid inorganic diluent.

Claim 13

A bleach composition characterized by a mixture ot a bleach auxiliary according to any of Claims 1 to 10 and peroxygen bleaching agent wherein the mole ratio of peroxygen bleaching agent to iron complex is in the range from 2000:1 to 10:1.

Claim 14

A laundry composition characterized by: (a) at least 5% of laundry matrix materials comprising one or more of (i) up to 75% of organic surfactant selected from anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof, (ii) up to 90% of inorganic or organic detergency builder, and (iii) up to 40% each of peroxygen bleaching agent and/or organic activator therefor, and (b) a bleach auxiliary according to any of claims 1 to 10 in an amount sufficient to provide from 0.02% to 5% of iron complex.

Claim 15

A composition according to Claim 12 characterized by a dry mixture of

Claim 16

(a) from 30% to 93.9% of spray dried base powder comprising from 0% to 75% of surfactant and from 5% to 90% of detergency builder, (b) from 0.1% to 20% of an agglomerate comprising from 0.02% to 5% of iron complex, and (c) from 5% to 35% of particulate peroxygen bleaching agent; the composition additionally comprising from 1% to 15% of ethoxylated nonionic surfactant sprayed onto the dry mixture of base powder, agglomerate and peroxygen bleaching agent.

Claim 17

(a) from 30% to 93.9% of spray dried base powder comprising from 0% to 75% of surfactant and from 5% to 90% of detergency builder, (b) from 0.1% to 20% of an agglomerate comprising from 0.02% to 5% of iron complex, and (c) from 5% to 35% of particulate peroxygen bleaching agent; the composition additionally comprising from 1% to 15% of ethoxylated nonionic surfactant sprayed onto the dry mixture of base powder, agglomerate and peroxygen bleaching agent.

Claim 18

A composition according to Claim 12 in water-releasable combination with a water-insoluble dispensing carrier.

Claim 19

A composition according to any of Claims 12 to 14 characterized by the addition of at least 1%, preferably from about 2% to about 20% sodium carbonate or bicarbonate.

Claim 20

A process of making an iron complex consisting essentially of a water soluble, substantially non-colloidal complex of iron and a multi-dentate ligand forming chelatinc agent, the chelating agent being a hydroxycarboxylic acid having the general formula I wherein R is CH 2 0H, CHO or C0 2 H, n is from 4 to 8, m is from 3 to n, or a salt, lactone, ether, acid ester or boric ester thereof, the process being characterized by: (a) preparing an aqueous solution containing the multidentate ligand-forming chelating agent together with a second water-soluble complex of iron and auxiliary chelating agent, the first and second iron complexes being such that over a specified pH range both complexes are stable against hydrolytic degradation to water-insoluble iron species, the first iron complex having greater stability than the second iron complex within the specified pH range but having lower stability or being unstable at pH values below the pH range, the aqueous solution having a pH within the specified pH range and containing each chelating agent in an amount equal to or greater than that independently required for complete iron complexation, and (b) maintaining the aqueous solution within the specified pH range until chelation of iron by the multidentate ligand forming chelation agent is complete.

Claim 21

A process of making an iron complex consisting essentially of a water soluble, substantially non-colloidal complex of iron and a multi-dentate ligand forming chelatinc agent, the chelating agent being a hydroxycarboxylic acid having the general formula I wherein R is CH 2 0H, CHO or C0 2 H, n is from 4 to 8, m is from 3 to n, or a salt, lactone, ether, acid ester or boric ester thereof, the process being characterized by: (a) preparing an aqueous solution containing the multidentate ligand-forming chelating agent together with a second water-soluble complex of iron and auxiliary chelating agent, the first and second iron complexes being such that over a specified pH range both complexes are stable against hydrolytic degradation to water-insoluble iron species, the first iron complex having greater stability than the second iron complex within the specified pH range but having lower stability or being unstable at pH values below the pH range, the aqueous solution having a pH within the specified pH range and containing each chelating agent in an amount equal to or greater than that independently required for complete iron complexation, and (b) maintaining the aqueous solution within the specified pH range until chelation of iron by the multidentate ligand forming chelation agent is complete.

Claim 22

A process of bleaching soiled fabrics characterized by contacting the soiled fabrics with an aqueous wash liquor containing (a) from 10 -4 to 10 -1 , preferably from 5.10 -3 to 5.10 -2 mmoles / litre of a water-soluble complex of iron and a multidentate ligand-forming chelating agent, and (b) from 0.01 to lOg/litre of peroxygen bleaching agent wherein the mole ratio of peroxygen bleaching agent to iron complex is from 2000:1 to 10:1, the complex has a bleach activity of at least 10%, and the stability of the complex against hydrolytic and oxidative degradation to water-insoluble iron species is at least 75%.

Claim 23

A process of bleaching soiled fabrics characterized by contacting the soiled fabrics with an aqueous wash liquor containing (a) from 10 -4 to 10 -1 , preferably from 5.10 -3 to 5.10 -2 mmoles / litre of a water-soluble complex of iron and a multidentate ligand-forming chelating agent, and (b) from 0.01 to lOg/litre of peroxygen bleaching agent wherein the mole ratio of peroxygen bleaching agent to iron complex is from 2000:1 to 10:1, the complex has a bleach activity of at least 10%, and the stability of the complex against hydrolytic and oxidative degradation to water-insoluble iron species is at least 75%.