CA2101448A1 - Preoxyacid bleach precursor compositions - Google Patents

Abstract

2101448 9213798 PCTABS00014 Solid peroxyacid bleach precursor compositions are provided in which the external surfaces of a particulate peroxyacid precursor material is treated with from 2 % to 20 % by weight of a solid organic acid compound of Mpt > 30 ·C and an aqueous solubility of at least 5g/100g water at 20 ·C. The bleach precursor material, when so treated, perhydrolyses after 3 minutes in a standard test at 20 ·C, to at least 90 % of the extent of the untreated bleach precursor material under the same conditions. Preferred organic acid compounds are monomeric aliphatic hydroxycarboxylic and polycarboxylic acids such as citric, lactic and glycolic acids.
Detergent compositions containing the treated peroxyacid bleach precursor particulates are also disclosed.

Description

37g8 2 1 ~ PCI`~U~92/~

PERO~AC~ID Bl,~E~lR~QR ~C)MP~$I~IONS

This invention relates to solid peroxy acid bleach precursor compo~itio~ a~d especially to particulat~ deterge~t compositio~s incorpora~ing inorgal~ic perhydr~te bleaches together with N- or C)-acyl group - containi~g per~ycarboxylic acid bleach precursors ~so- ~:
called bleach activators~. Such com~sitio~s have come iIltO ;~
widespread use in recent years as heavy du~y fabric cleaning ~;
products~ particularly in a~tomatic washing machines. ~he growth i~ usage of bleach activators has mirrored a decrease in fabric wash temperatures which itself has acc~mpanied an increase ill the ;
proportion of ~abrics that are coloured.
. .
One problem ~hat has become more sig~ Scant as a result of these tretlds is that of damage to fabric colours and materials caused by the development of localised high concentrations of bleaching species.
High bleach concentrations can arise around any particulate bleaching species for several reasons. The bleaching species may itself have . n intrinsically low solubility9 its solubili~ ~ay have been ; -hindered by ~he presence of other materials su~h as viscous :
surfactant phases or the agitation regime i~ the immediate ~;
environme~t of the bleach species may not be high eIlough ~o disperse the dissolved bleach. Where a bleach activator forms a compollent of the composition the potential problem is increased. Ln ;
addition to thc potential ~or localised high concentra~ioIls of ::
perhydroxyl ion arising from dissolution of the inorganic perhydxate normally co~tained in laundry detergent compositions, the perhydrolysis of the ble~ch activator to form peroxycarboxyl anions 2101~
WO g2/137~8 PCI'/US92/0~664 can give rise to significant localised pero~ycarboxylate bleach conceIltrations.
-:
The de~elopment of so-called coIlcentrated products and their delivery via dispensing devices placed in the machine drum together with the fabric load has merely se~ed to exacerbate these problems.
Accordi~gly a need exists to provide detergent compositions in which the bleach activator is incorporated i~ a fo~ that minimises and pre~erably eliminates damage to fabric colours aIld materials during :~
its dissolution alnd perhydrolysis iEl the wash liquor.

The prior ar~: coIlta~s ~mer~us e~amples of bleach activators coated or agglomeEated so as to increase their stability on storage in detergent comp~sitio~s and/or to influence their solution behaviour.

EP-A-0070474 discloses grar~u!ate bleach activators prepared by spray drying an aqueous pumpable dispersion containiIlg an N-acyl or O-acyl compound together with at least one water soluble cellulose ether, starch or starch derivath~e in a weight ratio of activator to coa~ing of from 98:2 to 90:10.

GB~A-1507312 discloses the c~ating of bleach activators with a mi~ture of alkali metal C~ - C22 fatty acid salts i~ admixture with the correspo~ding ~atty acids. GB-A~1381121 employs a molten coating of j~ç~ C14 - Clg ~atty acid xnixtures to protect solid bleach acti~ators. GB-A-1441416 discloses a similar process ernployi~g a mixture of C12 - C14 fatty acids and Clo - C20 aliphatic alcohols. EP-A-0375241 describes stabilised bleach activator extrudates in which Cs- C1g alkyl peroxy carboxylic acid precursors are mixed with a binder selected from anionic and nonionic surfactants, film forming polymers fatty acids or mixtures of such binders.

EP-A-0356700 discloses compositions comprisirlg a bleach activator, a water soluble film forming polymer and 2-15~o of a C3-C6 polyvalent carboxylic acid or hydroxycarboxylic acid for enhanced stability and ease of dispersion/solubility. The carboxylic acid, of Yo 9~13798 2 1 0 1 ~ ~ ~ P~l`/U~i~2/~

which a preferred e~cample is eitric acid, is dry mixed with the bleach activator and theIl granulated with the film forming polymer.
The citric acid is asserted to provide ~ enhanced rate of dissolution of the bleach acti-lator granules.

EP-A~382464 conce~s a process for eoating or e~capsulation of solid partieles includi~g bleaching compounds and bleach acti~rators in which a mel~ is ~ormed of coating material in which the partieles form a disperse phase, the melt is destabilised and then caused to crumble to a particulate material in which the disperse phase particles are embedded i~ the COIl~UOUS (coati~g~ phase. A variety of coat~g materials are disclosed a~d certain materials such as polyacrylic acid and cellulose ace~te phthala~ are taught as be~g useful where release of the coated material is dependeIlt on pH.

The s~erall emphasis in the prior art has ~us been orl the protection of the bleach ac~avator against a hostile enviro~ent dur~rlg storage and relatively little attention has bee~ paid to the dissolu~ion ;~
characteristics of the coated or agglomerated material in use. Where ~;;
coating and/or agglomeratlorl has been prsposed with poorly soluble materials such as fatty acids9 this has resulted in a rate of perhydrolysis of the bleach acti~ator which is slower than that which would occur if it had not been so protected. A~y use of more rapidly soluble materials such as citric acid has bee~ in the context of an a~glomerate component in which more rapid solution of the bleach activa~or has been the objective. In both instances, because perhydrolysis comme3~ces as soon as the d~tergent product starts to dissolYe and ~rm an alk~line hydrogen peroxide solutio~ the problem of localised peroxy acid bleach concentrations has remained unsolved.

One solutiorl to this problem would be to delay the start of perhydrolysis in order to aYoid the ~abric colour damage problems associated with the dissolution behaviour of other detergent product components. However it is important thas perhydrolysis of the bleach precursor and subsequent dispersion of the peroxycarboxylate wo 92/13798 2 1 ~ 8 PCI/US92/00664 bleach is as rapid as possible whè~ it commences bec~llse of the short wash times of modern automatic washing machines.

The problem that arises in simultaneously satisfying these two objectives does not appear to have been recognised in the prior art.

It is l~ow~ that the rate of perhydrolysis of a percar~o~cylic acid bleach precursor in an aqueous o~cidising medium is progressively reduced as ~he pH of the medium is reduced, particularly whe~ the p~I falls below the pKa of the pare~t acid of the precursor leaviIlg group. However the fatty acids taught as coating agents in the prior art are llot usefill as a mea~s of providi~g a low pH e~Yiro~ment in aqueous wash liguor because of their i~solubility. Moreover fatty acids used as coating a~/or agglomer~ing agen~ ~or pero~y acid bleach precursors have been found to reduce the rate of perhydrolysis of the lat~er, therelby redl;lcing the e~fectiYene~s of the resultant peroxycarbo~cylic acid bleach.

The Applicant has ~ow surprisingly ~ound that acidic materials having certain specified characteristics can be used to providç a sur~ace treatment to particulate pero~y acid bleach precursors, tha~
delays the orlset of perhydrolysis dllring dissolution of the product under ~he corlstrained agi~ation conditio~s ~f a loaded washing ma~hine drum without adversely hinderiIlg perhydrolysis when it occurs.

According to the present invention there is provided a solid peroxyacid bleach preeursor composition comprising a particulate peroxyacid bleach precursor material, said precursor containing one or more N- or O aeyl groups and having a Mpt> 30C, the external surfaces of said particulate peroxy acid bleach precursor material being treated with an organic acid compound so as to adhere said compound to said external sur~aces, said compound being preserlt i~ an amount of from 2% to 20~o by weight of the treated particulate, said organic acid compound having an aqueous solubility of at least Sg/lOO~g of water at 20C and a Mpt ~ 30C, wherein said ~reated particulate bleach precursor ma~erial produces, a~er 3 21~1~48 VO 92/1379B PCI/US92~00$64 minutes in a E~eaker Perhydrolysis Test at 20C, at least 90~ of the pero~y acid that is produced under the same eonditio~s by said particulate bleach precursor material in untreated ~orm.

Preferably the organic ~id compound is a mo~omeric or oligomeric carboxylate that has an aqueo~s solllbility of at least 20g/1OOg of water at 20~C. Most pre~erably the eompound is a mo~omeric aliphatic car~oxylic acid of very hîgh solubility and Mpt~40 C.

I~ is important for the purposes of the present inven~io~ tha~ the e~ternal surfaces of the peroxy bleach precursor particulate, whether in the ~orm of individual particles or agglomer~es~ are t~eated so hat the organic acid co~npound is adhered thereto. The trea~nent can be such as to provide the u~mpound in the form of a co~ti~uous or disconti~uous coating or as masses of the acid comp~und dispersed o~ the particulate surace or as i~dividual particle~ :~
dispo~ed at random on the sur~ace. The requireme~t i that the surface treatment material be immediately available, OIl e~posure to an aque~us medium, to dlssolve ra~idly a~d proYide a~ a~id pH
en~ironment arourld the exteric~r of the bleach precursor particulate.
~or this reason, irlcorporation of the organic acid compound as an - agglomerati~g agent dispersed with~ ehe pero~yacid bleach precursor pa~iele does not provide the benefit of the inventioIl. This is beeause, u~der ~he conditions of dissolution of a concentrated graIlular laundry product, particularly when delivered to washing machi~e drum by a dispellsing device, an agglomerated but non sur~ace ~reated pero~cyacid bleach precursor perhydrolyses to a significant e~tent and generates high bleach concentrations that give rise tQ localised ~abrie damage.

The solid peroxyacid bleach precursor eompositions of the presen~
invention inco:rporate precursors contai~ing one or more N- or 0-acyl groups, which precursors can be selected from a wide xange of classes. Suitable classes include anhydrides, esters, imides and acylated derivatives of imidazoles and o~cimes, ~d e~amples of useful materials wi~ these classes are diselosed in GB-A-1586789.
The most preferred classes are esters such as are disclosed in wo 92/137~ 2 1 ~ 8 6 PCI'/VS92/00~64 GB-A-836988, 864,798, 1147871 an~ 2143231 and imides such as are disclosed iIl GB-A-855735 & 1246338.

Specific O-acylated precursor compounds irlelude 2,3,3-tri-methyl hexanoyl oxyben~ene sulfonates, be~y~ oxybe~e~e sulfonates and penta ace~yl glucose.

Particularly p~erred preeursor compounds are the N-,N,NlN1 tetra acetylated compound of formula O O
Ii 11 3 \ / C C~I3 N - (c~I2~x ~ ~ \
C~3 C~ C -CH3 Il 11 .~
O
wherein x call be O or ~ integer between 1 & 6.

Exa~ples i~clude ~etra ace~l methylene diamine (TAMD) in which x= 1, te~a acetyl ethylelle diamine ~D) in which x=2 and tetraacetyl hexyle~e dia~e CTAHD) iD which x=6 These and analogous compounds are described in GB-A-907356. The most pre~erred peroxyacid bleach precursor is TAED.

Solid peroxyacid bleach precursors useful in the present inven~ion have a Mpt ~ 30C a~d pre~erably ~ C~ Such precursors will normally be in fine powder or clryst~lline form in which at least 90~ by weight of the powder has a particle size ~150 micrometers.

This powder ean !be surface treated directly but is more usually agglomerated, prior to surface treatmen~, to form particulate rnaterial, at least 85 ~o of which has a par~icle size between 4()0 and 1700 mierometers. Suitable agglomerating agents include C12-(: 18 fatty acids, C12-C1g aliphatic alcohols condensed with from 10 to 80 moles of ethylene o~cide ~er mole of alcohol, cellulose derivatives such as me~hyl, carboxymethyl and hydroxyethyl cellulose, polyethylene glycols of MWt 4,000 - 10,000 and polymeric materials such as polyvinyl pyrrolidone.

vo~12/l3798 2i~ 8 PClr/US92/0~664 Agglomerat~ particulate precursor material does not itself provide the benefi~ of the invention but is a pre~erred form of the precursor to which the organic acid compound is applied as a sur~ace treatment.

The organic acid compound ~ust satisfy several criteria. Firstly it must be a solid at ambient tem~eratures and so must ha~e a Melti~g Point of at least 30C and preferably of at least 40C. Preferred organic acid compounds will have a Melti~g Point in e~cess of 50C.

Secondly the organic acid compou~d ~ust be ~ghly soluble i~ water at ambie~t temperaeures, highly soluble be~g defined for ~e purpvses of the prese~t iIl~rention as at lea~t Sg of the acid dissolvi in lOO~g of distilled water a~ 20C. Pre~erably the org~c acid compou~d has a solubili~ o~ at least 2~/lOOg OI water at 20C and most pre~rably the organic acid compou~d will dissolve in its own weight of water at 20C.

Thirdly the orgaI~ic acid compound should have no more than a mi~or e~fect9 and pre~erably substanti~lly no effec~ on the rate of perhydrolysis oiF ~e peroxyacid bleach precursor under well agitated unco~strained conditions. Unc~strai~ed, well agitated conditioIls are defined ~or ehe purposes of the present Lnventio~ as those existing in the Beaker Perhydrolysis Test described in detail hereina~er. A
treatment material that has 'no more than a minor e~t' on the rate of perhydrolysis of the precursor is definedg for the purposes of the present in~entiorl, as that which a~er 3 minutes in ~e Beaker Perhydrolysis Test at 20C, permits the production of at least 905~
of ~he peroxyacid that is prod~ced under the same conditions by the untreated bleach precursor material. Prefer~ly the rates of perhydrolysis of treated and untreated material are substantially identical.

Organic acid compolmds suitable as trcating agcnts ~r the purposes of the present invention comp~ise aliphatic or aromatic morlomeric or oligomeric carboxylates and pre~erably comprise monomeric alipha~ic carboxylic acids. Examples of such aliphatic aeid

2 1 ~ I ~ 4 8 P~/U~ 2/0~

compou~ds are glycolic, glutamic, citraco~G, succinie9 l~lactic and citric aeids. The acids are applied at levels of ~rom 2% tQ 2U% by weight of the treated particulate, more preferably ~rom 2% to 15 and mos~ pre~rably from 3% to 10% by weight of the trea~ed particulate . Glycolie acid at a level of appro~cimately 5 % by weight of the treated particulate is a partieularly prefe~red sur~ace treating agent.

The surface trea~me~ of the ble~eh precursor particulate with the orga~ic acid compound can be carried out in several ways and the process i~el~ is not critical to ~he present irlvelltion.

The organic acid compound may be sprayed on as a molte~ material or as a solutiol~ or dispersion in a solvent/carrier liquid which is subsequently removed by evaporation. The organic acid compound caII also be applied as a powder coating e.g. by elec~rostatic tech~iques although this is less pre~erred as the adherence of -;
powdered coating material is more difficult to achieve and can be `;
more e~pensive.

Molten coati~g is a pre~erred tec~ique for orgarlic acid compotlnds of Mpt ~ 80C such as glycolic and l-lactic acids but is less corlvenie~t ~r higher Melti~g Point acids (i.e. ~100C) sueh as citric acid. For organic acid comp~unds of Mpt~80C, spray on as a solution or dispersion is preferred. C1rga~ic solvents such as ethyl and isopropyl alcohol can be used to form the solutions or dispersio~s, although ehis will necessitate a solYerlt recovery stage in order to makc their use economic. However, t!he use of orga~ic solvents also gives rise to safety problems such as flammability and operator safety and thus aqueous solutions or dispersions are preferred.

Aqueous solutions are particularly advantageous where the organic acid compound has a high aqueous solubility (e.g. citric acid) and the solution has a suffleiently low viscosity to enable it to be handled.
Preferably a concentra~ioll of at least 25 % by weight of the organic acid compound in the solvent i used in order to reduce the 2 1 ~ 8 .~0 92~13798 P~/US92/00664 drying/evaporatioIl load after sur~ace treatment has taken place. The treatment apparatus ca~ be any of ~hose normally used for this purpose, such as inclined rotary pans~ rotary drums aIld fluidised beds.

Solid peroxyacid bleach precursor composidon~ i~ accorda~ce with the invention can take a variety of physical ~orms~ s the surfaGe trea~ed peroxyacid bleach pre~ursor particles may themselves be ~ .
incorporated into other solid compositions suGh as tablets, extmdatgs and agglomerates. The particulates ca~ also be suspended in no~aqueous liquid eompositions i~ which the org~c acid~sur~ce treat~g ma~erial is insoluble and inert. However, the preferred application ~or the solid peroxybleach precursor compositions of the inve~tioll is as pa~iculate compo~erlts of gra~lllar detergent eompositions, particularly the so called eoncentrated detergeIlt co~npositions tha~ are added to a washing machine by mea~s of a ;~
dosing device placed in the machine dI~m with the soiled fabric load.
Collcentrated granular detergent compositions dispensed into the wash liquo~ via a dosing de~ice are mc)re subject to dissolutiotl -problems thaIl compositions ~dded via the dispensirlg compartment of a washing machine because, in the initial stages of a wash cycle, the agitaltion in the immediate envi~nmen~ of the product is inhibi~ed by ~he presenGe o the fabric load. Whilst this ca~ co~stitute a beIlefit i~ :~
permi~cing ~e development of high transient conce~trations of ~ilder and surfactant, the development of high tr~siellt peroxyacid concen~ra~iorls can, as noted previously~ lead to ~abric arld colour damage. The coated peroxyacid bleach precursor particulates of the present i~vention, when incorporated into conce~trated detergent products delivered to the wash liquor via a dispensing deviee, mitigate if not eli~ate this problem.

Detergent compositions ineorporating the surface treated peroxy ~cid bleach precursor particulates will normally eontain from 0.5 % to 10~ of the precursor, more frequently ~rom 1% to 8% and most preferably from 2% to 6%, on a composition ~veight basis.

2101~
W~ 92/137g8 P~/US92/00664 Such detergent compositions will, of course, contain a source of alkali~e hydrogen peroxide necessa~y to form a pero~yacid bleaching species in the wash solu~ion and prèferably will also contain o~her components conve~ional in detergent compositions. Thus preferred de~ergent compositions will incorporate o~e of more of surfactants, org~c and inorg~c builders, soil uspendi~g and ~nti-redeposition agents, suds suppressors, e~zymes, fluoresce~t whitening age~ts photo ac~iva~d bleaches~ perfilmes a~d colours.

Detergent compositions incorporating the surface treated particulate peroxyacid precursors of the present inve~tion will include ~
i~orga~ic perhydrate bleach, normally in the fo~ of the sodium salt, as the source of alkal~e hydrogen peroxide i~ the wash liquor. This perhydrate is normally ~ncorporat~ at a level of ~rom 3 % to 22% by weight, more preferably ~rom 5% to 20% by weight and most pre~erably ~rom 8% to 18% by weight of the compo~itio~.

The perhydrate may be a~y of the inorganic salts sueh as perborate percarbonate, perphosphate a~d pcrsiLicate salt~ but is conYeIl~ioIlally an a~ali metal perborate or percarbonate. Whilst fabric coiour damage arising ~rom compositions in accordance with the invention is low, irrespective of whether a perborate or percarbonate salt is employed, the improvement in comparison with u~coated precursor pa~ticula~es is more noticeable wi~h percarbonate bleach as this causes greater fabric colour damage in ~he absence of any coati~g on the bleach precursor.

Sodium percarbonate, which is the preferred perhydrate, is an addition conllpound havi~g a fo~mula correspo~ding to 2Na~CO3.3H202, aIld is available commercially as a crystalline solid. Most commercially available material includes a low level of a heavy metal sequestrant such as EDTA, 1-hydro~yethylidene 1, 1-diphosphonic acid (HEDP) or an an~ino-phosphonate, that is incorporated during the ma~ufacturing process. For the purposes of the de~ergent composition aspect of the present invention, the percarbonate can be incorporated into detergent compositions without additional protection, but preferred executions of such compositions ~101~(18 VO 92/137g8 PCI`/US92/0066 utilise a coated form of the material. Although a variety of coatings can be used, the most economical is sodium silicate of SiO2:Na20 ratio from 1.6:1 to 3.4:1, pre~erably 2.8:1, appli~ as an aqueous solution eO give a level of ~rom 2~ to 10~, (normally ~om 3% ~o 5 %) of silicate solids by weight of the percarbonate. Magnesillm silicate can also be included i~ the coating.

The par~icle size ra~ge of the &ryStalliIle perca~onate is ~rom 350 micrometers to 450 micrometers with a mean of appro~imately 400 micrometers. When çoated, the crystals have a size in the range from 400 to 600 micrometers.

Whilst heavy metals prese~t in the sodium carbonate used to manufacture the perearbonate can be controlled by the i~clusio~ of sequestrants in the reaction ~xture, tbe percarbonate still requires proteetiorl from heavy metals ~rese~t as i~purities in other ingredients of the product. According]ly, in detergent compositions u~ilising percarbollate as the perhydrate salt, the tot~l level of Iro~, Copper and Ma~ga~ese ions i~ the pro~ucl: should not e~ceed 25 ppm and preferably should be less thall 20 ppm in order to avoid an unacceptably adverse e~ect on percarbonate stability. Detergent compositio~s in which alkali metal percarbo~ate bleach has enhanced s~ability are disclosed i~ ~he ~pplica~ts copeIld~g British Pateng Applica~ion No. 9021761.3 (Attorney's Docket No. CM343).

A wide range of sur~actants ca~ be used in the dete~ent composi~îo~s. A typical listi~g of anionic, ~o~ionic, ampholytic and zwi~erionic cl~sses, and species of these surfactants~ is given in U.S.P. 3,929,678 issued to Laughlin a~d HeuriIlg on D cember, 30, 1975. A list of suitabl~ cationic sur~ac~a~ts is given i~ U.S.P.
4,259,217 issued to Murphy on March 31, 1981.

Mixtures of anionic surfactants are suitable herein, partieularly blends of sulphate, sulpho~ate andlor c~rboxylate surfac~ants.
Mixtures of sulphonate and sulphate sur~actants are normally employed ~ a sulphonate to sulphate weight ratio of from S:1 to 1:2, preferably from 3:1 to 2:3, more preferably from 3:1 to 1:1.

2 1 0 ~
WO 92t~3798 P~/US92~00664 Preferred sulphonates iDclude alkyl benzene sulphona~es havi~g from 9 to 15, especially 11 to 13 carbon a~oms i~ the alkyl radical9 and alpha-sulphonated methyl ~atty acid esters in which the ~atty acid is derived from a C12-(: 18 i~atty source9 preferably ~rom a C16-Clg ~atty source. In each instance the catio~ is an alkali metal, preferably sodium. Preferred sulphate sur~actalats i~ such sulphonate sulphate mi~tures are alkyl sulphates havillg ~rom 12 to 22, preferably 16 to 18 carbo~ atoms in thç alkyl radical. Another use~ul surfactant system co~pnses a ~x~ure of two alkyl sulphat~ materials whose respective mean chain lengths dif~er from each o~her. C)ne such sygtem comprises a mi~t~re of C14-Cls alkyl sulphate and C1~-C1g alkyl sulpbate in a weight ~atio Of (~14-6~15: C16-(~18 of ~-~ from 3:1 to 1:1. The allyl sulpha~ may also be combLned with alkyl ethoxy sulphates havin~g ~rom 10 to 20, preferably 10 to 16 carbon aeoms in the alkyl radical ~d a~ average degree of ethoxylation of l to 6. The catîon in each iIIstanc is aga~n an alkali metal, preferably sodium.
C)ther ~ionic surfactants suitable for the purposes of the illvention are the al~li met~l sarcosina~es of ~ormula R-CON ~R) CH~ COOM
whe~ R is a Cg-C17 linear or brallched alkyl or alkenyl group, R' is a C1-C4 alkyl group a~d M is an alkali metal ion. Preferred exa~nples are the lauroyl, Cocoyl (C12-C14), myristyl and oleyl me~yl sarcosinates in the form of their sodium salts.

One class of nonionic sur~actants useful in the present inYention comprises condensates of ethylene o~cide with a hydrophobic moiety, providing sul~ac~ts having an average hydrophilic-lipophilic balance (HLB) in the range from 8 to 17, preferably from 9.S to 13.5, more preferably ~rom 10 to 12.5. The hydrophobic (lipophilic) moie~y may be aliphatic or aromatic in ~ature a~d the }ength of the polyo~yethylene group which is condensed with any particular hydrophobie group can be readily adjusted to yield a water-soluble compound having the desired degree of balance betvveen hydrophilic and hydrophobic elements.

~101~
~o 92/1379~ P~r/lJss2/00 Especially pre~erred no~onic surfactants of this type are the Cg-C1s primary alcohvl ethoxylates contai~ing 3-8 moles of ethylelle oxide per mole of alcohol, particularly the C14-C1s primary alcohols con~g ~8 moles of ethylene o~cide per mole of alcohol and the C12-C14 primary alcohols containin~ 3-5 moles of ethylene o~cide per mole of alcohol.

Another class of nonionic sur~actants comprises al~l polyglucoside compounds of general ~rmula nH~n~)tzx wherein Z is a moiety derived from glucose; R is a satura~ed hydrophobic allyl group ~hat contains from 12 to 18 carbo~ atoms; t is from O to 10 ~nd n is 2 or 3; x is from 1.3 to 4, the compou~ds includ~g less than lO~o unreacted ~atty alcohol and less th~ 50~o short chain alkyl polyglucosides. Com~ounds of ~his t~rpe and their use i~ detergenl: compositions are disclosed in EP-B ~70074, 0070077, 0075996 and 0094118.

A ~urther class of sur~actants are the se~-polar surfactants such 2S
axr~ine oxides. Suit~ble amine ~xides are selected from mono Cg-C20, pre~rably Cl~C14 N-al~yl or all~enyl a~e oxides and propyl~ne-l ,3~iamine dio~cides wherein the remaini~g N positions are substituted by methyl, hydro~yethyl or hydroxpropyl groups.

Ca~ionic surfactants can also be used in the detergent compositions herein a~d suitable quaternary ammonium sur~ar-tants are selected from mono Cg-C16, preferably Clo-C14 N~alkyl or alkenyl ammonillm sl;arfac~a:nts wherein remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

The detergent composition comprise from 5% to 20~a of surfactan~
bu~ more usually comprise from 7% to 20%, more preferably from 10% to 15% surfactant ~y weight of the compositions.

~0 92/137~8 2 i 01~ A 8 PCI`/US~2/0066~ ' Combinations of sllrfac~Ilt types are pre~erred, more especially anio~ nonionic alld also anionië-nonio~ic-cationic blends.
Particularly preferred combinatio~s are described in C3B-A-2040987 and EP-A 0087914. Although the su~facta~ts can be incorporated into ~he compositions as mixtures9 it is preferable to control the point of addition of each sur~a~tant in order to optimise the physical characteristics of the co~nposition aIld avoid processL~g problems.
Preferred modes and orders of surfactant addition are described hereina~er.

AIlogher highly pre~erred component of deterge~t compositioIls incorporating the coa~ed peroxy acid precursor particulates of ~be inve~tio~ is a deterge~t builder system compnsing one or more non-phosphate de~ergent bl~ilders. Thçse can include, but are not res~ricted to alkali metal carbonates, bicarbonates, silicates9 alu~osilicates~ mo~omeric polycarbo~ylates, homo or copolymeric polycarboxylic acids or their salts in wh;ch the polycarbo~ylic acid comprises at least two carboxylic r~di~als separated from each other by not more tha~ ~wo carlbon atoms, organic phosphona~es a~d aminoalkylene poly (alkylene phosphonates) aIld mi~tures of a~y of the ~regoing. The builder system is present in an amount of iF~om :~
25% to S0~6 by weight of the c~mposition, more pre~rably ~rom 30~ to 60% by weight.

Pre~erred builder systems are free of boron compounds and any polymeric organic materials are pre~erably biodegradable.

Suitable silicate are those having an SiO2:Na2Q ratio in the range from 1.6 to 3.4, the s~called amorphous silicates of SiO2: Na~O
ratios from 2.0 to 2.8 being preferred. These materials can be a~ded at various points of the manufacturing process, sueh as in a slurry of componen~ that are spray dried or in the form of an aqueous solution seirvin~ as an agglome~ating agent i~or other solid components9 or, where the silicates are themselves in particulate form, as solids to the other particulate components of the compositon. H~wever, for compositions in which the percentage of 2.~ 8 ~10 92/13798 PC~/U~9~/00664 spray dried col~pone~ts is low i.e. 30%, it is preferred to include the amorphous silicate i~ the spray-dried compongnts.
.

Within the silicate class, highly pre~erred materials are crystalline layered sodium silicates of general formula NaMSi~O2x+ l-Y3H2~) whereill M is sQdium or hydroge~, x is a number ~rom 1.9 to 4 and y is a ~umber from 0 to 20, Crystalli~e layered s~illm silica~es of this type are disclosed ~ EP-A~164514 aIld methods for their preparatio~ are disclosed i~ DE-A-3417649 and DE-A-374~043. For the purposes of the presen~ i~velltio~, x in l~e ge~eral for~ule above has a value of 2, 3 or 4 a~d is preferably 2. More pre~erably M is sodium arld y is 0 and pre~erred examples of this for~ula comprise the ~ and ~ forms of Na~Si2Os. These materials are available &om Hoechst AG FRG as res~ectiYely NaSKS-11 and NaSK5-6.
The most preferred material is -Na2Si~Os~ (NaSKS-6).
C: rystalline layered silicates are i~corporated either as dry mixed solids, or as solid component:s of agglomerates with other components. :

Whilst a r~nge of aluminosilicate ion e~cha~ge materials can be used, preferred sodium aluminosilicate zeolites have the unit eell formula N~z [(~1~2 ) z (5i02 )y ~ ~H 2 wherein z arld y are a~ leas~ 6; ~he molar ratio of ~ to y is ~rom 1.0 to 0.5 a~d x is at least 5, pre~erably from 7.5 to 276, more pre~erably from 10 to 264. The alumino~ilicate materials are in hydrated form and are pre~erably crystalline, containing ~rom 10% to 28%, more preferably from 18% to 22% water in bound form.

The above alumi~osilicate ion excha~ge materials are further characterised by a particle size diameter of from 0.1 ~o 10 micrometers, preferably from 0.2 to 4 micrometers. The term "particle size diameter" herein represents the a~rerage particle size diameter of a given ion e~change material ~s deter~ined by conventional analytical techniques such as, ~or example, microscopic WO 92~13798 2101 4 ~ ~ PC~/US92/01)6M

determination utili~ing a scannir~g electron microscope or by means of a laser granulometer~ The aluminosilicate iOIl excharlge materials are further characterisecl by their ~alcl~m iOIl exchange capacity, which is at least 2~0 mg equivalent of CaC03 vvater hardness/g of aluminosilicate~ calculated on an anhydrou basis~ and whieh generally is ~ the range of from 300 mg eq./g to 352 mg eq./g. The aluminosilicaee io~ e~;cha~gg materials herein are still filrther characterised by their ealeium ion e~change rate which is at least 130 mg equivalent of CACO3/litre/minute/(g/litre) ~2 grains (: a+ +/
gallo~ u~e/gram/g2110n)] of alu~osilicate (anhydrous basis)~
and which ge~erally lies withi~ the range of from 130 mg equivalent of CaC03/litre/minute/(gram/litre) [2 ~grains/gallontminute/ :-~ram/gallon)] to 390 mg equivalellt of CaC03/litrgJminute/ ~:~
(gram/litre) [6 grains/gallon/mi~ute/~gram/gallon)], based on calcium ~::
ion hardness. -:
Optimum aluminosilicates for builder purposes exhibit a calcium ion exchange rate of at le~st 260 mg equivaleIlt of CaC03/litre/ minute/
(gram/litre) [4 grains/gallon/minute/(gram/gallon)~.

AlumiI~osilicate ion exchange materials use~ul in the practice of this inven~ion are commercially aYailable and can be naturally occurring materials, but are prefer~bly synthetically derived. A method for producing aluminosilicate ion e~chaIlge materials is discussed in IJS
Patent No~ 3,985,669. Preferred synthetic crystalline alumiIlosilicate ion e~change materials useful herei~ are available under the desig~ations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and ~:
mi~ res thereof. In a~ especially pre~erred embodiment, the ~:~
c~ystalli~qe alun~inosilicate ion excbange material is Zeolite A and has the formula ~ 12 ~(A102 ) 12 (sio2)~2 ~. X~2 wherein x is ~rom 20 to 30, especially 27 Zeolite X of formula Na86 [(A12)86(Si2)106] 276 H20 is also suitable, as well as Zeoli~e HS of formula Na6 [(A102)6(SiO~)6] 7.5 H~ 0).

2101~
~/0 92/13798 P~/OS92/00664 Suitable water-soluble monomeric or oligomenc carboxylat~ builders can be selected from a wide range of comp~u~ds but such compounds pre~rably have a first carbo~yl logarithmic acidity/constallt (pKl) of less ~an 9, pre~rably of between 2 a~d - 8.5, more preferably of bet~Neen 4 and 7.5.

The logarithmic acidity constant is defined by reference to the equilibrium H+ + A =lEI+A
where A is the fully io~ized car~o~ylate anio~ of the ~ilder s~lt.

~-~ The equilibrium constant as therefore K1 -- (H+ A) I(H~) (A) and pK1 = log~

For the purposes of this specification, acidity cons~ants are defimed at 25C a~d a~ zero ionic strength. Literature values are talcen where possible (see Stability Cons~ts of Metal-Ion Complexex, Special Publication No. 25, The Chemical Society~ London~: where doubt arises ~hey are determined by potentiometric ti~ation using a ~glass eleetrode.

Pre~rred carboxylates can also be defined in ~erms vf their calcium ion stability cons~nt (pR~a~ ~) defined, a~alogously to pKl, by the equatio~s PKCa~ ~ logl0~Ca~ +

where ~Ca+ + (Ca~ + A) (Ca+ +~ (A) Preferably, the polycarboxyla~ has a pK C~a+ + in the range ~rom abou~ 2 to about 7 especially from about 3 to about 6. Once again 2 1 ~ 8 ~N~ 92/13798 P~/US92/0 literature values of stability constant are taken where possible. The stabili~y co~stant is defilled at 25C and at zero io~ic stre~gth using a glass electrode method of measurement as described i~ Co~plexation in Analytical Chemistry by ~ders Ringbom (1963).

The carbo~ylate or polycarbo~cylate buailder c~ be momomeric or oligomeric i~ type although mosomeric polycarbo~cylates are generally pre~erred for re~o~s of cost a~d perfor~se~

Monomeric and oligomeric builde~s can be selected ~rom acyclic, alicyclic,-heterocyclic and aromatic carbo~ylates havill the ge~eral ~ormulae ~:
~ .
( a ~
Rl --X~C- ~2 2 m (b) o~
(c) Yp~q whe~ein Rl represents H,C1 30 all~l or alkenyl optio~ally substitutKI by hydroxy, car~o~y, sulfo or phosphono groups or attached to a polyethyle~o~cy moiety contai~i~g up to 20 ethyle~eoxy groups; R~ represe~ts H,C1~ alkyl, alke~yl or hydro~y alkyl, or alkaryl, sulfo, or phosphono gro~.lps;
X represents a single bo~; C); S; SO; SO2; or NRl;
Y represe~ts H; carboxy;hydro~y; carbo~methylo~cy; sr C ~ 30 alkyl or alk nyl optio~ally substituted by hydru~y or carbo~cy groups;
Z represen~s H; or carbo~cy;

vo 92/l37g8 2 1 0 1 ~ '1 8 P~r/USg2/00~64 m is an ~teger from 1 to 10;
n is ~ integer from 3 to 6;
p, q are i~egers from 0 to 6, p ~ q being from 1 to 6; and wherein, X, Y, and Z each have the same or dif~rent represe~tations when repea~ a given molecular formula1 and wherein at least o~e Y or Z in a molecule contain a carboxyl group.

Suitable car~o~ylates co~ta~g o~e carbo~ group include lactic :~
acid, glycolic ~cid and ether derivatives thereof as disclosed i~
Belgian Patent ~os. 831,368, 821,369 and 821,370.
Polycarboxylates con~aining two carbo~y groups include ~e water-soluble salts of succinic acid, malonic acid,, (etlhylenediQxy) diace~ic ~cid, maleic acid~ diglyeolic acid, tartaric acid7 tart~o~ic acid and fumaric acid, as well as the ether carbo.xylates described iIl German Of~e~legen~chrift 2,446~686~ and 2,446,687 a~d U.S~ Pate~t No~ -

3,935,257 and the sulfinyl carbo~ylates descri~ed in E~elgian Patent No. 840,623. Polycarboxylates co~taining three carbo~y groups iIIclude, iIl parti~ular, water-soluble citlates, aco~itra~es and citraconates as well as succinate derivatives such as the carboxymethyloxysuc~nates described in I3ritish Pate~t No.
1,379,241, lacto~cysucci~ates described in British Patent No.
1,389,7329 a~d a~osuccinates described in Netherlands Application 7205873, and the o~cypoly~arboxylate materials such as 2-oxa-1,1,3 propane trica~o~ylates described ill British Patent No.
1,387,~47.

Polycarbo~ylates con~ining four carbo~cy groups incldue oxydisuccinates disclosed i~ E~ritish Patent No. 1,261,829, 1~1J2~2 ethane tetracarboxylates, 1,1,3,3-propane tetracarbo~ylates and 1,1 ,2,3-propane tetracarboxylates. Polycarb~cylates contai~ing sul~o substituents include ~e sul~osuccinate derivatives disclosed in British Pate~t Nos. 1,398,421 and 1,398,422 and ~ U.S. Patent No.
- 3,936,4489 and the sulfo~ated pyrolysed citrates described in British PatentNo. 1,439,000.

Alicyclic a~d heterocyclic polycarboxylates include eyclopentane-cis,eis,cis-te~racarbo~ylates, cyclopentadienide pentacarboxylates, 21a~!l4~
WO 92/13798 PCI~/US92/00664 !

2,3,4,5-te~rahydro:fura~ cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran- cis - dicarboxylates, 2,2,5,5-tetrahydrofu~
tetracarbo~cylates, 1,2,3,4,5,~he~ e - he~ac~rbo~ylates and carboxymethyl derivatiYes of polyhydric alcohols sueh as sorbitol, ma~itol alld xylitol. Arolnatic polycarbo~ylates include mellitic acid, pyromellitic acid and ~he phthalic acid deriva~ives disclosed in British P~tent No. 1,4259343.
Of the above, the preferred polycarbo~cylates are hydro~ycarbo~ylates con~g up to three carboxy groups per molecule, more partieularly citrates.

The parent acids of the mo~omeric or oligomeric polycarboxylate _. chelating a~e~ts or miactures thereof with their salts, e.g~ cit~c acid or citrate/citric acid ~tures are also contemplated as components of builder systems of d~erge~t compositions in accordance with the preseIlt invention.

Other suitable water soluble orgaDic sal~s are the homo- or co~
polymeric pollycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxyl radicals separated from each other by not more than two carbon atoms.
Polymers of the latter type are disclosed in GB~A-1,596~7$6.
Examples of such salts are polyacrylates of MWt 2000 5000 aIld their copolymers with maleic anhydride~ such copolymers having a molecular weight of from 20,000 to 70,000, especially ab~ut 40,000.
These materials are normally used at levels of from 0.5% to 10~o by weigh~ more preferably ~rom 0.75% to 8%, most pre~erably ~om 1% to 6% by weight of the composi~ion.

Organic phosphonates and amino alkylene poly (alkylene phosphonates) inclu~e alkali metal etha~e l-hydroxy diphosphonates, nitrilo trimethylene phosphorlates, ethylene diamine tetra methylene phosphonates and diethylene triamine penta methyleIle phosphonates, although these materials are less preferred where the minimisation of phospborus eompounds in the compositions is desired.

2~01~sll~
Vl~g2/13798 PClfUS92~0~664 2' ~or the purp~ses of detergent compositions embodying the surface tr~ated bleach precursor particulates of the i~vention ~ the non-phosphate builder ingredient will comprise from 25% to 60% by weight of the compo~itio~s, more preferably from 30% to 60% by weight. Within the preferred compositions, sodium aluminosilicate such as Zeolite A will comprise from 20% to 60% by weight of the total amount of builder, a monomeric or oligomeric carboxylate will comprise ~rom 10~ to 305to by weigbt of ~e total amou~t of builder and a crystalline layered silicate will eomprise from 10% to 65% by weight of the total amount of builder. I~ sueh compositions the builde~ i~gr~ilen~ preferably also incorporates a coEnbi~atio~ of auxiliary inorg~c aDd organic builders such as sodium carbonate and maleic anhydride/acrylic acid copolymers in amo~ts of up to 35 ~o by weight of the total builder.

A~ti-redepositioIl and soil-sus~e~sioIl age~ts suitable herein ~clude cellulose deriYatiYes such as rnethylcellulose~ carboxymethylcellulose and hydroxyethycellulose, and homoo]r co~polymeric polycarboxylic æids or their salts. Polymers of this type include copolymers of malcic anhydride with ethylene, nnethylvinyl ether or methacrylic acid, the maleic anhydride constituting at least 20 mole percent of the copolymer. These materials are ~ormally used at levels of ~orn 0.5% to 10% by weight, more preferably from 0.75% to 8%, most preferably from 1 5~o to 6~ by weight of the composition.

Other useful polymeric materials are the polyethylene glycols, particlllarly those of molecular weight 1~10000, more particularly 2000 to 8000 and most preferably about 4000. These are used at levels of from 0.20~ to 5% more preferably from 0.25% to 2.5%
by weight. These polymers and the previously mentioned homo- or eQ-polymeric polycarbo~ylate salts are vaïuable for improving whiteness mainte~a~ce~ fabric ash depositiorl, and cleaning performance on clay, proteinaceous and oxidi~ble soils in the prese~ce of transition metal impurities.

Preferrecl optical brighteners are anionic in charaeter, examples of which are disodium 4,41-bis-(2-diethanolamino~anilino -s- triæin-21~ l8wo ~/13798 PCI`/USg2/~0664 ' -ylamino)s~ilbene-2:21 disulphonate, disodium 4,41~bis-(2-morpholino ~aniliI1~2-~riazin-~ylaminos~ilbene-2:2l-disulphonate,disodium 4, 41-bis-(2,4 dianilin~s-triæi ylamino)stilbe~e-2:21 - disulpho~ate, mo~osodlium 41,411-bis-(2,~
diaI~ili~s-~ 6ylamiIlo)seilbene-2~ sulpho~ate, disodium4,41 bi~-~2-al~ili~o~(N-methyl-N-2-~ydro~yethyl~o3-2-triaz~Il-~ylamino)stilbe~e 2,21 ~ disulphonate, disodium 4,41-bis-~phenyl~
2,1,3-triazol-2-yl)stilbe~e-2,21 disulph~ disodium4,41bis(2-a~lino~(l-methyl-2-~ydro~yethylamino)-s-triazin-~yl~o)stilbe~e 2,21disulpho~ate a~d sodium 2(stillb~
~n~aphth~11 ,21 :4pS)-1,2,3 - ~azole-21 1 sulphoIla~:

Soil-relea~e agents usefi~ compositio~s of the prese~ invention are con~entionally copolymers or terpoly~ers of terephthalic acid wîth ethylelle glycol a~d/or propyle~e glycol unîts Ln varîous arra~geme~ts. I~ples of s~ch pol~ers are dîsclosed ~ the commonly assigned US Pate~t Nos. 4116885 ~d 4711730 a~d Europea~ Publîshed Patent ApplîcatîoDI No. 0272033. A partîcular prei~erred polymer in accordance wîth EP-A~272033 has the ~ormula 3(~a~43~O.7~ .a5t~ a.~ )o.d~ os-asop~G~3c~3)o-75 Certain polymenc ~enals such as polyvî~yl pyrrolidones typîcally of MWt 50~20000, preferably 10000 15~, also form useful agen~s in preven~i~g ehe tra~sfer of labile dyestu~fs be~wee~ ~abrics dur~g ~e washî~g process.

Another optional detergen~ composition i~gredîe~t is a suds suppr@ssor, e~cemplified by silico~es, a~d sîlica-sîlieo~e mi~ctures~
Sîlicones can be ge~erally represented by alkylat~d polysilo~e matenals whil~ silica is ~srmally us~ finely divided ~orms~ -e~emplified by sîlica aerogels and xerogels a~d hydrophobic sîlicas of various types. These matenal~ ca~ b~ incorporated as partieulates i~ which the suds suppressor is advantageously releasably incorpora~:ed in a water-soluble or water~îspersible, sub~tantially 2101 ~
0 92/13798 PCr/US92/0066 ~3 non-surface-active detergent-impermeable carrier. Alternatively the suds suppressor can be dissolved or dispersed i~ a liguid carrier a~d applied by spraying on to one or more of the other com~onents.

As men~ioned above, usefill silicone suds controllillg ageIlts can comprise a mi~cture of an alkylated silo~ane, of the ~pe referred to hereiIlbe~ore, ~d solid silica. Such mi~ture~ are prepared by ~ffixing the silicone to the surface of the solid silica. A preferred silicone suds controlli~g age~t is represented by a hydrophobic sila~ated ~most preferably trimethyl-silaD ated~ silica hav~g ~ particle size in the range from 10 na~ometers to 20 ~ometers and a speGifi~
surface area above 50 m21g~ intimately admi~ed with dimethyl ~-~ silico~e fluid having a molecular weight i~ the ra~ge ~rom ab~ut 5 to about 200,000 at a weight ratio of silico~e to silanated silica of ~rom ab~ut 1:1 to about 1:2.

A preferred silicone suds controlling a~gent is disclosed in Bartollo~a e~ al. US Paterlt 3,933,672. Other parlicularly u~efill suds suppressors are the sel~-emulsi~ying silicone suds suppressors, described in (3erman Patent Application Dl'OS 2,646,126 published April 28, 1977. An example of such a compound is :0C0544, commercially available from Dow Conning, which is a siloxane/glycol copolymer.

The suds suppressors described above are ~ormally e~ployed a~
levels of ~rom 0.001% to 0.5% by weight of the composition, preferably from 0.01% to 0.1% by weight.

The pre~rred methods of incorporation comprise either application of th~ suds suppressors in liquid form by spray-oll to one or more of ~h~ major components of the compositioll or alternatively the formation of the suds suppressors L~to separate particulates that can the~ be mi~ed with the other solid com~onents of the composition.
The inc~rporation of the suds modifiers as separate particulates also permits the iIlclusion ~herein of other suds co~trolling materials such as C2~C24 fatty acids, microcrystalline waxes and high MWt copolymers of ethylene oxide and propylene oxide which would WO 9~/13798 2 1 0 1 ~ '1 g P~/US92/~06~4 ~

otherwise adversely affect the dispersibili~ of the matrix.
Techniques ~or forming such suds modifying particulates are disclosed in the previously mentioned Bartolo~ et al US Patent No. ~:
3,933,672. ::~

Another optional i~gredient useful in the present i~ventio~ is one or more enzymesO

Prei~err~ en~ym~ic materials i~clude the con~ercially a~ailable amylases, n~u~al ar~d al~aline proteases, lipase~, esterases a~d cellulases conventionally i~corporat~ into detergent eo~positions.
Sui~able e~ymes are discussed i~ US Pate~ts 3,519,570 and 3,S33,139.

~abric softenin~ agents can also be ~corporated into detergent co~positio~s i~ accorda~ce wi~ the present i~vention. Thes~ agents may be inorga~iG or organic iIl typeO Inorganic softe~in~g agents are e~amplified by the smectite clays disclosed in G13-A-1,~,898.
Orgaruc ~ric so~tening age~ts include the water i~soluble tertiary amines as disclosed in GB-A-1514276 ~md E~P-B-00l 1340.

Their combiDation with mono C12-Cl~ quater~ary ammonium salts is disclosed in E~P-B~2~527 ~ 528. Other use~ul or~ganic ~a~ric softening age~s are the dilong chain a~ides as disclosed in EP~B-0242919. Additional org~c ingredients of fabric softening sys~erlls include high molecular weight polyetlhylene o~;ide ~aterials as disclosed in EP-A-0299575 and 0313146.

Levels of smectite clay are normally in the range from 5% to lS~, morc pre~rably from 8% to 12~i by weight~ with the material being -~
added as a dry mixed component to the remainder of the ~orn~ulatio~
Org~c fabric softe~ing agents such 2s the water-insoluble tertiary amines or dilong chain amide materials are incorporated at levels of from 0O5 % ~o 5 % by weight, normally ~rom 1% to 3 ~ by weight, whilst the high molecular weight polyethylene oxide materials ~nd the water soluble cationic materials are added at levels of from 0.1 ~o 2%, normally from 0.15% to 1.5% by weight. Where a portion 2 1 ~
~0 92/13798 P~r/U~92/00664 of the composition is spray dried, these materials can be added to the aqueous slurry ~ed to the spray drying tower, although in some i~stances it may be more ~o~venient to add them as a dry mixed par~iculate, or spray ~hem as a molteIl liquid o~ to o~her solid components of the composition.

The surface treated pero~yacid bleach precur~or particulates of the present invention are par~icularly usefill ~ co~ee~tra~ed gra~ular detergent compositions that are characterised by a relatively high densi~ compariso~ with col~ventional laundry detergent compositio~s. Such high de~sity composi~ons have a bulk de~sity of a~ leas~ 650 g/litre, m3re usually at least 7~ g/litre and more ~-~ pre~erably i~ excess of 800 g/litre.

Bulk d~nsity is measurecl by means of a simple ~ el and cup deviçe co~sisti~g of a conical fuDIlel moulded rigidly o~ a lbase and provided with a flap valve at its lower e~tremity to allow the conte~ts of the fu~el ~o be emptied i~to an a~cially alig~ed cyli~drical cup disposed below tbe filDnel. The ~u~nel is 130 mm and 40 mm a~ its respec~ive upper alad lower extremities. It is mounted so that the lower ex~remity is 140 mm above the upper surface of th~ base. The cup has an overall beight of 90 mm, ~ i~ter~al height of 87 m~ and a~
inten~al diameter of 84 mm. I :s nominal volume is 500 ml.

To carry o~t a measureme~t, the funn~l is filled with powder by hand pouring, thc flap valve is opened and powder allowed to overfill the cup. The filled cup is removed from t:he frame and excess powder removed from ~he cup by passing a straigh~ edged implemen~ e.g. a kni~e, across its upper edge. The filled eup is then weighed and ~he ~alue obtained for the weight of powder doubled to provide the bulk density in g/litre. Replicate measurements are made as required.

Concentrated detergent compositions also normally incorporage at least one mul~i-ingredie~t component i.e. they do not comprise compositions formed merely by dry-m~xing individual ingredients.
Composi~ions in which each individual ingredient is dry-mixed are WO 92/1379~ 210 ~ 8 P~JVS92~00664 generally dusty, slow to dissolve and also tend to cake and develop pOOF par~icle flow characteristics in storage.

Sub3ect to the above bulk densi~ and co~nponent co~tent limitatio~s, the compositions of ehe inventio~ can be made via a ~arie~ of me~hods includi~g dry mi~ing, spray drying9 agglomeration a~d grarlulatio~ a~d prefe~ed methods i~volve combinations of these tech~iques. A preferred method of making the co~positio~s involves a eombina~io~ of spray drying, agglomeration in a high speed mi~cer a~d dry mi~ing.

Pre~erred detergent ~ompositions in accordallce wi~h the invention comprise a~ least ~wo particulate multi-in~gredient compone~ts. The first componeIlt ~omprises at least 15 %, conYentionally ~rom 25 % ~o 50%, but more pre~erably ~o more thall 35~Zo by weight of the composition an~ the seco~ compone~t ~rom 1% to 50% 9 more pre~rably 10% to 40% by weight of the compositioIl.

The first compone~ comprises a par~iculate incorporating a~ anionic surfacta~t ~ aIl amou~t of from 0.75% to 40% by weight of the powder and one or more inorganic and/or orgaIlic salts in a~ almou~t of from 99.25% to 60% by weaght of ~he powder. The par~iculate ca~ have any suitable ~o~m such as gran~les, flakes, prills, maFumes or no~dles but is preferably graIlular. The grallules ~hemselves may be agglomerates formed by pan or drum agglomeration or by in~ e mi~ers bu~ are customarily spray dried particles produced by a atomising ~ aqueous slurry of the ~gredients in a hot air stream which removes most of ~he water. The spray dried granules are then subJected to densificatio~ steps, e.g. by high speed cutter mixers and/or compacting mills, to increase density before bei~g reagglomerated. For illustrative purposes, the first oomponeIlt is described hereinafter as a spray dried powder.

Suitable anionic surfactants ~or the purposes of the first componeIlt have bee~ ~ound to be slowly dissolving linear alkyl sulfate salts in which the alkyl group has an average of from 16 to 22 carbo~ atoms, and linear all~yl carbo~ylate sAlts in which the alkyl group has an 2101 ~'~8 ,~o ~2/1379~ P~T/USg2/(~0664 average of from 16 to 24 carbon atorns. l'he alkyl groups for both types of sur~actant are preferably derived ~om natural sources such as tallow fat and marine oils.

The level of anionic surfactant iYl the spray dried powder ~rming the first compo~ent is from 0.75~ to 40% by weight, more usually 2.5% to 25% preferably from 3~; to 20% aIld most pre~erably ~om ~% to 15% by weigh~. Water-soluble sur~ac~nts such as liIlear alkyl be~æ~e sulphonate or C~4-C1s alkyl sulphates call be included or alternatively may be applied subseque~tly to the spray dried powder by spray o~.

~-~The o~er ma3or ingtedient of the spraS~ dned powder is one or more inorg~c or organic salts ~hat proYide the crys~alline structure for the graIIules. The inorganic alld/or org~c salts may be water-soluble or wa~er-i~soluble, the laKer tg~e being comprised by the, or the ma~or part of the, water-insoluble ~lilders where ~ese ~orm part of the builder ing~edient. Sui~ble wate,r soluble ino~a~ic salts include the alkali metal carbonates and ljicarbonates. Allcali metal silicates other than crystalline layered silic~tes can also be present in the spray dri~d gr~ule provided that ~luminosilicate does not ~rm part of the spray dried component.

HoweYer, in ~oIlcentrated deterge~t compositio~s it is preferred that water-soluble sulphate, particularly sodium sulphate, should not be present at a level of more than 2.5% by weight of the composition.
Pre~rably no sodium sulphate is added as a separate ingredient and its incorpolratio~ as a by-product e.g. with sulph(on)ated sllrfactants7 should be ~mised.

Where an aluminosilicate zeolite forms the, or part of the, builder ingredie~, it is preferred that it is not added directly by dry-mixing to the other components, but is incorporated into the multi~ gredient compoIlent~s). Where incorporation of the zeolite ~kes place in the spray~ried granule, any silicate present should not form part of the spray~ried granule. In these circumstances, incorporatioll of the silicate can be achieved in several ways, e.g. by producing a separate .... ,, .. . , .. . . ~... ... .. . . . . . . .

WO92/137~8 Z~ 3 PCI`/US92/aO664 ' silicate-contail~ling spray-dried particulate, by incorporating the silicate i~to an agglomerate of otlher ingredie~ts, or more pre~erably by adding the silicate as a dry mixed solid i~gredient.

The first component ca~ also include up to 15% by weight of miscellaneous ingredie~ts such as brighteners, a~ti-redeposition agents, photoactivated bleaches ~such as tctrasulfonated zinc phthalocyani~e) and heavy metal sequeste~ing ag~nts. Where the first compo~ent is a spray dried powdgr it will no~ally be dried to a moisture conteIIt of from 7 ~ to 11 æ by weiglht, more preferably from 8% to 10% by weight of the spray dried powder. Mois~re co~teIl~ of powders produced by other processes such as ~~ agglomeration may be lower and c~ be ~ the range 1~10% by weight.

The particle size oP ~e first c~ponerlt is co~ventianal and preferably not more than 5~o lby weight should be above 1.4mm, while not more than 10~ by weight should be less than û.15 mm in maxi~um dimension. Preferably at least 6Q~ d most preferably at least 80%, by weight of the powder lies between 0.7 mm a~ 0.25 mm in size. Por spray dried powders, tlhe bulk derlsity of the par~icles ~rom the spray drying tower is co~ventio~ally in the r~ge from 54() to 6()0 g/li~e and this is then enhanced by fur~her processing steps such as size reduction in a high speed cutter/mixer ~llowed by compactiorl. Alternatively7 processes other than spray dryi~g may be used to ~rm a high density particulate directly.

A second compotlerlt of a preferred compositiorl in accordance with the inventio~ is another r~ulti-ingredient particulate containing a water soluble sur~actant.

This may be anionic, noniorlic, cationic or semipolar in type or a mi~ture of any of these. Suitable surfactants are listed hereinbefore but pre~rred surfactants are C14-Cls alkyl sulphates, linear Cll-C~s alkyl benzeIle sulphonates and fatty C14-Clg methyl ester sulphonates.

wo s2Jl37s~ 2 i O 1 ~ ~ 8 ~cr/uss2/00664 The seco:nd component may have any suitable physical ~orm, i.e. it may take the form of flak~s, prills, marumes, noodles, ribbo~s~ or granules which may be spray~ried or non spray~ried agglomerates.
Although the seco~d component could in theory comprise the water soluble surfactant on its ow~ in practice at least one organic or inorg~c salt is includ~ to facilitate processi~g. This provides a degree of crystalli~ he~ce acceptable flow characteristics~ to the particula~e and may be any o~e or more of the organic or inorganic salts present in the first component.

The par~icle size range of the seco~d compo~e~ should be such as tn obvia~e segre atio~ from the pa~icles of the first eomponent when .~blended therewith. Thus not more than 5% by weight should be above 1.4 mm while not more than 10% should be less th~ O.lS mm in maximum dimensio~.

The bulk dgrlsity of the second component will be a ~unction of its mode of preparation. However, the pre~erred form of the secorld component is a mech~cally mi~ed agglomerate which may be made by addi~g the ingredients dry or with arl agglomerati~g agent ~o a pan agglomerator, Z blade mixer or more preferably an in-line mixer such as those manufactured by Schugi (HollaIld) BV, 29 Chroomstraat 8211 AS, Lelystad, Netherlands and Gebruder Lodige Maschi~enbau GmbH9 D~790 PaderborD 1, ElseIlerstrasse 7-9, Postfaeh 2050 ~.R.G. By this mea~s the second componeIlt can be given a bulk density ~ the range from 650 g/litre to 1190 g/litre more preferably from 750 g/litre to 850 g/litre.

Preferred compositions include a level of alkali metal carbonate in the second compo~ent corresponding to an amount of from 3 % to lS~o by weight of t~e composition, more pre~rably *om 5% to 12%
by weigh~. This will provide a level of carbonate in the second eompo~ent of from 20% to 40% by weight.

A highly preferred ingredient of the second component is also a hydrated water insoluble aluminosilieate ion e~change material of the synthetic zeolite type, de~cribed hereinbe~re, present at from 10~o 2101~8 wo 92/1379g Pcr/uss~/oo664 :

to 35% by weight of the second component. The amount of water insoluble alu~osilicate material incorporated in this way is ~rom 1 ~Zo to 10% by weigh~ of the Gomposition~ more pre~erably from 2%
to 8~o by weight.

In one process ~or prepari~g ~he seco~d compone~t, the sur~ac~t salt is formed in situ in a~ ~line mi~er. The liquid acid ~rm af the surfac~t is added to a mi~cture of par~culate ~hydrous sodiunn carbos~e and hydrated sodium aluminosilicate in a contin~ou~ high speed blender, such as a Lodige KM mi~er, and neu~:ralised to form the surfac~t salt whilst ma~ta~ the particulate sature OI the mixture. The resultant agglomerated mi~cture ~orms the second ~-~ compone~t which is ~en added to other components of the product.
In a vanant of this p~ocess, the surfacta~t salt is pre-neu~alised and added as a viscous paste to the mi~h~re of the other L~gredients. In the variant, ~he m~cer serves m.erely to agglomerate ~he ~gredie~ts to ~orm the second compo~ent.

In a particularly preferred ~rocess ~or malcing detergent compositions incorporating the coated peroxyacid bleach precursor particulates of ~he inYention, par~ of the spray dried product comprising the first granular component is diverted a~d subjected to a low level of nonionic su~acta~t spray o~ before be~ng reblended with the remai~der. The second gra~ular compohent is made using the pre~err~d process described above. The first and second components together wtth the coated bleach precursor particulate and the perhydrate bleach, other dry mi~ i~gredients such as any carbo~ylate chelati~g agent, soil-release polymer, silicate of co~ventio~al or crys~all~ne layered type, and e~yme are then ~ed to a conveyor belt, fro rn which they are transferred to a horizontally rotating dNm in which perfume and silico~e suds suppressor are sprayed on to the product. In highly pre~erred composi~ions, a further drum mixi~g step is employed in which a low (approx. 2% by weight) ievel of finely divided crystalline material is introduced to i~crease density and improve grallular flow characteristics.

2101~48 NO 92/13798 P~/US92/00664 In preferred co~centrated detergent products incorporatin~g a~ alkali metal percarbo~a~e as the perhydrate salt it bas bgen ~ou~ necessary to co~erol several aspects of the product such as its heavy metal io~
co~te~t and its equilibrium relative humidi~ Sodium percarbo~ate-co~tainî~g compositio~s of this type having enh~ced stabili~ are disclosed in the commonly assigned British ~pplicatio~ No.
9021761.3 filed October 6 1990 Attorney's Doclcet No. (:~M343~

Compositions ~ accordance with the illvention caD also benefit from delivery systems that provide tra~ient lo- alised high concelltrations of produc~ in the drum of ~ ~ut~matic washing machine at the s~are of the wash cycle~ thereby also avoiding problems associated with 31OSS of product ~ the pipework or sump of the mach~e.

DeliYery to the drum ca~ most easily be achieved by incorporation of t~e composition in a bag or coIltainer from which it is rapidly releasable a~ the start of ~e wash cycle i~ response to agitation, a rise in te~perature or immersio~ e wash water in the drum.
AlternatiYely the washi~g mach~rle itself may be adapted to permit direct addition of the composition to the drum e.g. by a dispensi~g arrangeme~t in the access door.

Produc~ comprising a detergent composition enclosed i~ a bag or cont~iner are usually designed in such a way that co~ er i~tegrity is maintained i~ the dry state to prevent egress of the contents whe~
dry, l~ut are adapted f~)r release of the container contents on exposure to a wa~ g environment, ~ormally on i~nersio~ in an ~queous solution.

Usually the contaiDer will be flexible, sl~ch as a bag or pouch. The bag may be of fibrous construction coated with a water impermeable protecitive material so as to retain the contents, ~uch as is disclosed in E~uropean published Pate~t Application No. 0018678. AlternatiYely it may be formed of a water-insoluble synthetic polymeric material provided with an edge seal or closure designed to rupture i~ aqueous media as disclosed in l~uropean published Patent Application Nos.
0()11500, 01)11501, 0011502, and 0011968. A convenient form of 2 ~
WO 92/1379~ PCI/US92/006~i4 wa~er ~ra~gible closure eomprises a water soluble adhesive dispo~ed along and seal~g one edge of a pouch formed of a w~ter impermeable polymeric film such as polyethyle~g or polypropylene.
In a variant of the bag or container form, la~ted sheet produets can be employed in which a central fle~ible layer is impregllated and/or coated with a composition and then one or more outer layers are applied to produce a fabric-like aesthetie effect. The layers may be sealed together so as to remain attached during use or may separate o~ contact wi~h water to ~acilitate the release of the coated or impregnated material.

An alternative laminate form comprises one layer embossed or ~deformed to provide a series of p~llch-like co~ta~ers i~to each of which the deter~nt somponeIlts are deposited in measured amounts~
with a second layer overlyi~g tlhe first layer and sealed thereto in those areas beteen the pouch-like contai~ners where the two layers are in co~tact. The compo~ents may be deposited in particulate, paste or molten ~orm and the lami~ate layers should preveIlt e~ress of the contents of the pouch-like containers prior to their additio~ to water.
The layers may separate or may remain attaehed together on co~tact with water, the only re~uiremen~ being that ~he struc~ure should permit rapid release of the contents o~ the pouch-like contairlers into ~olution. The ~umber of pouch-like containers per unit area of substrate is a matter of choice but will normally vary between 500 and 25,000 per s~are metre.

Suitable materials which can be used ~or the fle~cible laminate layers in this aspect of the invention include, among others9 sponges, paper and wove~ a~d non-woveIl fabries.

However the preferred means of carrying out the process of the mven~ioIl is to introduce the composition into the liquid surrourlding the fabrics that are in the drum via a reusable dispensi~g device having walls that are permeable to liquid but impermeable to ~he solid composition.

2 1 01~8 VO 92/1379~ PCl/IJS92/00664 Devices of this kind are disclosed in European Patent Application Publication Nos. 0343069 & û343070. The latter Applicatio~
discloses a device comprising a fle~cible sheath in the form of a bag extending ~rom a support ring def~ing an orifice9 the orifice being adapted to admit to the bag su~fice~t product or one washing cycle in a washing cycle. A portioIl of the washi~g medi~m flows through the orifice into the bag, dissolves the product, ~d the s~lutioIl then passes outwardly through the orifice into the washing medium. The suppQrt ring is provided wi~h a masking arraIlgement to preve~t egress of wet~ed, Imdissolved, product, ~is arrangement typically comprising radially extendi~g walls extending ~rom a ceneral boss in a spoked wheel configuration, or a similar stmcture in which the walls have a helical form.

The inventioll is illusgrated in the following non limiting Examples, in which all percentages are on a weight basis u~less otherwise stated.

WV ~2/13792 i ~ P~r/US92100664 .

In the detergent compositions, the abbreviated component identifications have the ~llowing meanings:

C12LAS : Sodium linear C12 alkyl benzene sulphonate TAS : Sodium ~llow alcohol sulphate C14115A~ : Sodium C14-( 15 allcyl sulphate TAE~ : Tallow alcohol etho~sylated with n moles of ethylene o~ide per mole of alcohol 45E7 : A Cl~ls p~onu~tly linear primary alcohol _. condensed with an-average of 7 moles of ethylene oxide CnAFE6 S : A C12-C13 pnmary alcohol condensed with 6.5 moles of ethylene oxide.
PEG : Polyethyleneglycol (MWtnonnally follows) TAED : Tet~aacetyl ethylene diamine Silicate : Amorphous Sodium Silicate (SiO2:Na2O ratio norrnally follows) NaSKS-6 : Crys¢¢Lalline layer~d silica¢~e of formula Na2Si20s Carbon~¢e : Anhydrous sodium carbonate CMC : Sodium carboxyme¢thyl cellulose Zeolite A : Hydrated Sodium AlumiQosilica¢te of formula Nal2(Al~SiO2)l2- 27~20 haYing a primary par~icle size in the ~nge from 1 to 10 micrometer~
PQlyacrylate : Homopolymer of acrylic acid of MWt 4000 Ci¢tra¢te : Tn-~dium ci¢¢~rate dihydra¢~e 2 1 ~
~VO 92~1~798 PCI~,~US92/00664 Photoactivated : Tetra sulphonated Zinc Bleach phthalocyanine MA/AA : Copolymer of 1:4 maleic/acrylic acid, average molecular weight ab~ut 80,000.
MYEMA : Maleic anhydride/vi~yl methyl ether copolymer, belieYed to have an average molecular weight of 2409000. This material was prehydrolysed wi~ NaOH before addition.
Perborate : Sodiumperborate tetrahydrate of nominal - ~or~ula NaB~.3~2o.~2o2 Perborate : Anhydrous sodium perbora~e bleach ~-~ Monohydrate empiri~al for~ula NaB02.EI20~
Percarbonate : Sodium Percarbonate of no~al formula 2Na2C03.3~1202 Enzyme : Mixed proteolytic a~d amylolytic enzyme sold by Novo I~dus~ries AS.
l3rightener : Disodium 4,4'-bis(2-morpholiIlo~a~ilino-s-triazin-~ylamino~ s~ilbene-2:2'-disulphonate.
DETPMP : Dieth~ene triamine penta (Methylene phosphonic acid), marke~ed by Monsanto under ~he Trade l~ame Dequest 206 Mi~ed Suds : 25% para~f~ waxMptSOC, 17~
Suppressor hydrophobic silica, 58~o paraffin oil.

21(JlllL~3 WO 92/1379X PCI/U~;9~0066q For the purpose of the presen~ invention, unrestrained dissolution conditions are defined as those existing in the Beaker Perhydrolysis Test as carried out USillg a Sotax Dissolution Tes~er ~odel AT6 supplied by So~x AG CH 4008 BASEL Switzerland. This Apparatus comprises an array of polycarbonate beakers, each capable of hold~g 1 litre of wa~er, supported in a thermostatically controlled water ba~. Each beaker is provided with a padclle stirrer whose xpeed can be controllled.

Two beakers in the Sotax Tester are employed in the perhydrolysis procedure using the ~ollowing method:

1. Set water bath to re~uir~d te~perature ~20C).
2. Add 1 litre distilled water to each Sota~ beaker ~nd allow to equilibrate ~o required ~e~perature.
3. Sample accurately 2 x l.Og samples of detergent and precursor.

4. Prepare a number of titratio~ beakers by adding:
25 ml 3:2 glacial acetic acid distilled water solution together with 2 ice cubes

5. Set the stirfing speed of the SC)tZlX to 150 rpm.

6. Add ~he first sample to Sotax beaker No. 1 and start the clock (t=C) ~utes). Add S ml potassium iodide solution to the first titration beaker.

7. Take a 10 ml ~lig.uot from Sota~ beaker No. 1 and discharge into the first titration beaker at t = 1 rniIlute.

8. Add the second sample to Sotax beaker No. 2- at t = 1 minute a~d add S ml potassium iodide ~o a second titration beaker.

9. Titrate the first aliquot against 0.005 m sodium thiosulphate svlution until the solution is first decolourised (The colour is slowly regenerated as the solu~ion warms and the perhydratei reacts wi~h the iodide).

10. Take a 10 ml aliquot from Sotax beaker No. 2 at t = 2 minutes and discharge into the seeond titration beaker and r t t 9 epea s ep

11. Take further aliquots at the following times (t--minutes) 2 i ~
~VO 92/13798 PCI`/US~2~Q06M

~Ç~ÇL~ Beaker No. 2 (t) (t) ~ 21 Tlhe aliquots from Beakgr No. 1 at 1 miDute and ~om ~eaker Mo. 2 at 2 minutes constitute replicates and the results are aver~ged to give a figure from which the ~o perhydrolysis is calcula~d.

Exa~nple 1 TAED in ~ e powder fonn (particle size 90% by weight ~150 micrometer~" was agglomerated with TAE25 to give particles in which 85~; by weight was betwee~ D micrometers and 1700 micrometers. This material was divided into five ~actions identified as A-F, of which fraction A was untreated a~d the remaiIlder were :-treated as follows Su~ce Treating Material B 5% octanoic acid C 5 % polyacrylic acid (MWt 2,000) ~:~
D 5% glycolic acid :E~ S~a ci~ric acid The treatments were all applied by ha~d spraying into a small coating ::
drum. The octaIIoic acid was applied as a melt at 60C whilst the remainder were applied as aqueous solutions at ambient temperature (20C). The citric acid solution was S0~ by weight, the glycolic acid solution was 66% by weight and the polyacrylic acid solution was 50% by weight.

2 1 ~
wo 92/13798 Pc~ Jss2/0 Material frvm each fraction was then inGorpora~ed into a model detergent formulation h~ving the composition iIl parts by weight.
.
C 12LAS - 9.0 :
TAS 2.8 Dobanol 45E7 3.8 Zeolite A 23.5 Citrate 7.5 MA/AA 3.75 Carbo~ate 17.0 Silicate 4.2 (SiO2:~a2O=2:1~
DE~TPMP 0.4 CM(: 0 S
Percarbo~a~e 18.7 TAED . 5~85 Miscellaneous 3.00 The five formulations were then subjected to a Bealcer Perhydrolysis Test as hereinbefore described and gave the perv~yacid yields shown in Table 1 . Results are given for 1,3,5,10 lS & 20 minutes elapsed time and are expressed in percent of the thevretically available w~ight of per acid.

Table I
minutes ~om s~a~t of perhydrolysis Product withTAE:D fraction 1 3 5 10 15 20 A 37.3 74.2 86.0 93.9 97.8 97.2 B 23.2 60.1 75.9 90.8 97.4 96.5 ~9.0 67.2 77.2 ~8.2 90.8 90.0 D 37.6 73.7 85.1 94.9 97.5 98.6 E 36.8 74.5 87.2 92.5 96.8 97.6 It can be seen that formulations containing ~e fractions D & E give subst~ntially the same peroxyacid yield as that conta~ning fraction A, (both after 3 minutes and throughout the perhydrolysis reaction), WO 92/1379B 2101~ 4 8 PCI/IJS9~/00664 indicating that the perhydrolysis under uncons~ra~necl dissolution coIlditio~s was substantially unaffected by the treatment . By contrast formulatio~s containing ~ractions B & C ShQWed a lower pero~y acid yield, particularly in the in~ial peri~ of the perhydrolysis.

E~a~
The ~ormulations contai~g TAED fractions A ~ D of E~ample 1 ~;
were subjected to a filll scale washing machine test using Miele au~omatic washing machines (Model W7543 set to the Short Wash cycle at 40C. E~ach machirle was loaded with ~ur cotto~ bedsheets : `
(3.3 kg) and lOOg of the for~ulation was added go the fabrics iIl the ::
. machine drum via an Arielator (~TM) dispe~si~g device. 12 litres of water of 150 ppm hard~ess (e~pressed as CaC033 with a Ca:M~
ratio of 3:1 was fed ~o each machi~e.
Two machines, adapted to allow openi~lg of the loading door during the cycle for sampling purposes, were used to carry ou~ the same procedure as employed in the Beaker Perhydrolysis Test . The Results are shown in Table II and are expressed in the same manner as for Table I

~able II
minutes from start of wash cycle Prsduc~
wi~h TAED fraction 1 3 5 10 15 20 A 31.5 56.1 82.1 92.1 89.4 89.4 :
1~ 9. 1 50.6 68.~) 99.5 9~.5 96.7 It can be seen that, u~der the eo~strai~ed dissolutio~ conditions of a loaded washing machi~e, the product contai~ g fracgion D (the glycolic acid-sur~ace treated TAED), perhydrolyses more slowly thaIl the product containing fractio~ A (the ulltreated material)9 duri~g the initial stages of the wash cyele. This shows that the glycolic acid surface treatment of the TAE13 inhibits perhydrolysis during the period of high localised product co~centration existing at the star~ of the wash cycle, where the high aqueous solubility of the acid is believed to create a low pH environment around the TAED

WO 92/1379X 2 i ~ 8 Pcr/~JS~2/00664 ~o particles. Nevertheless, in the later stages of the wash cycle, the yield of peroxy acid from the treated TAED is Ibetter than from the untreated material, indicating that delayed release of the TAED
results in its more effective conversion in~ pero~y aeid.

xam~ 3 A full scale washing machine test was ca~ried out compariIIg three formulations co~ta~g fractions B, C & D of ~he surface treated precursor of Example 1. The ~ractions were added respectively to a modified form of the detergen~ ~or~ulatio~ of E~sample 1 irl vvhich the sodium percarbonate was replaced by the same weight of sodium perbora~e moIlohydrate.

The washing machi~e comparison employed the same technigue as that used in Example 29 save that the wash tempçrature was 20C.
This temperature is typical of Ihat foun~d during the initial cold fill stage of European wash cycles. Results are sh~wn below in Table III

Table III
minutes fro~ start of wash cycle iE;ormulation with ~ac~ion 1 3 5 10 15 20 B 4.6 33.6 54.7 74.8 78.0 80.3 C: 4.6 32.6 54.3 80.7 84.8 8~.0 D 3.65 54.8 70.8 83.0 88.5 85.0 This shows that a peroxy acid bleach precursor sur~ace treated in accordance with the inve~tion provides superior yields of pero~y acid under realistic washi~g conditio~s, compared to sur~ace trea~ment precursors that are not in accordance with the invention.

A washiIlg machine comparison of ~ormulations similar to tha~
carried out in Example III and incorporati~g precursor ~ractions A,B, C & E was carried out to include bleach sensitive coloured fabric swatches in the fabric load. These swatches were made of 2101fl~
WO 92/13798 PCl`/U~92/00664 100æ lambswool woven fabric with purple 48 dye (Design No.
W3970) supplied by Borval Fabrics, Albert Street, Huddersfield, West Yorkshire, England. 24 replicates of each treatment were performed and ~he swatches were then graded visually for fabric colour damage by an expert panel USillg the ~ollowing grading ~:
system.

Three c~loured swatches demonstrati~g di~fenng degrees of eolour damage are used as standards to establish a 4 point scale in which 1 represents 'virtually no damage' and 4 represen~s 'very damaged'.
The ~hree standards are used to define the mid points betweeIl the various descriptions of colour damage viz virb~ally no damage 2 slight damage 3 damage 4 verydamaged Two expe~ parlellists are used and their results are averaged.

Using this technique to compare colour damage resulting from use of ~rmulatiolls contaLning precursor fractio~s A,B,C & E the following results were ob~ained % oif swatches having grade formulation wi~h Overall precursor ~raction 1 2 3 4 Grade A S0 29.2 8.33 12.5 1.83 B 52.2 26.1 21.7 0 1.70 C 47.8 3~.4 17.4 4.4 1.7~
E 66.6 16.6 10.5 6.2 1.56 It can be seen that a formulation incorporating fraction E i~
accordance with the inverltion produces appreciably less ~abric colour damage than noIl surface treated precursor or surface trea~ed precursors not in accordance with the inven~iorl.

2 1 ~
WO 92/1379X PCl /U~i9~/00664 .
x~m~le V
The washing machine comparison of Example IV was repeated using formulations containing TAED fractioIls A & D of Example 1, as well as an additional TAED fraction ~ compnsing fraction A further agglomerated with 10% by weight of glycolic aeid (on total agglomerate weight basis). The formulatio~s were subjected to a coloured swatch degradation test as described in E~ample IV and gave the following results % of swatches having grade Overall 2 3 4 Grade A16 20 25 38 2.83 D29 38 29 4 2.08 9 35 35 22 2.70 It can be seen that fraction D, incorporatiIlg 5% glyeolic acid sur~ace treated precursor particulates in accordance with the inventio~, has a markedly lower overall damage grade than the untreated fraction A.
By contrast, the use of 10%, i.e. double the level, of glycolic acid as an agglomerating agent results in little decrease in damage grade relative to the Imtreated materi~l. This confirms the importance of sur~ace treatment of the bleach precursor particulates in obtaining the fabric damage reduction benefit of the inYentlon~

.,

Claims (22)

1. A solid peroxyacid bleach precursor composition comprising a particulate peroxyacid bleach precursor material, said precursor having a Mpt> 30°C and being selected from the group consisting of compounds containing at least one N-acyl group and compounds containing at least one O-acyl group, the external surfaces of said particulate bleach precursor material being treated with an organic acid compound so as to adhere said compound to said external surfaces, said acid compound being present in an amount of from about 2% to about 20% by weight of the treated particulate, said organic acid compound having an aqueous solubility of at least about 5g/100g of water at 20°C and a Mpt greater than about 30°C, wherein said treated particulate bleach precursor material produces, after 3 minutes in a Beaker Perhydrolysis Test at 20°C, at least about 90% of the peroxy acid that is produced under the same conditions by said particulate bleach precursor material in untreated form.

2. A solid peroxyacid bleach precursor composition according to claim 1 wherein the organic acid compound has an aqueous solubility of at least about 20g/100g of water at 20°C.

3. A solid peroxyacid bleach precursor composition according to claim 1 wherein the organic acid compound is selected from the group consisting of monomeric or oligomeric carboxylates.

4. A solid peroxyacid bleach precursor composition according to claim 3 wherein the organic acid compound is a monomeric aliphatic carboxylic acid having a MPt greater than about 40°C.

5. A solid peroxyacid bleach precursor composition according to claim 4 wherein the organic acid compound is selected from the group consisting of glycolic, 1-lactic and and citric acids and mixtures thereof.

6. A solid bleach peroxyacid precursor composition according to claim 4 wherein the amount of treating material is from about 2%
to about 15% by weight of the composition.

7. A solid peroxyacid bleach precursor composition according to claim 6 wherein the amount of treating material is from about 3%
to about 10% by weight of the composition.

8. A solid peroxyacid bleach precursor composition according to claim 7 wherein particulate peroxyacid bleach precursor material is treated with a molten organic acid compound selected from glycolic and 1-lactic acids to provide a coating to the external surfaces of the particulate bleach precursor material.

9. A solid peroxyacid bleach precursor composition according to claim 7 wherein the external surfaces of the particulate peroxyacid bleach precursor material are treated with a solution or dispersion of citric acid.

10. A solid peroxyacid bleach precursor composition according to either one of claims 8 & 9 wherein the organic acid compound is applied as a finely divided spray.

11. A solid peroxyacid bleach precursor composition according to claim 1 wherein the precursor is selected from the group consisting of esters and imides.

12. A solid peroxyacid bleach precursor composition comprising a particulate peroxyacid bleach precursor material, said precursor having a Mpt> 30°C and being selected from the group consisting of compounds containing at least one N-acyl group and compounds containing at least one O-acyl group, the external surfaces of said particulate bleach precursor material being treated with an organic acid compound selected from the group consisting of glycolic, 1-lactic and citric acids and mixtures thereof so as to adhere said compound to said external surfaces, said acid compound being present in an amount of from about 2%
to about 20% by weight of the treated particulate, wherein said treated particulate bleach precursor material produces, after 3 minutes in a Beaker Perhydrolysis Test at 20°C, substantially the same amount of peroxy acid as is produced under the same conditions by the particulate bleach precursor material in untreated form.

13. A solid peroxyacid bleach precursor composition according to claim 12 wherein the peroxyacid bleach precursor contains at least one N-diacyl moiety.

14. A solid peroxyacid bleach precursor composition according to claim 13 wherein the peroxyacid bleach precursor is a tetraacylated alkylenediamine.

15. A solid peroxyacid bleach precursor composition according to claim 14 wherein the peroxyacid bleach precursor is tetraacetyl ethylenediamine.

16. A solid peroxyacid bleach precursor composition according to claim 15 wherein the particulate precursor material comprises agglomerated particles of the precursor, the agglomerated particles being treated with the organic acid compound.

17. A solid peroxyacid bleach precursor composition according to claim 16 wherein the agglomerating agent is selected from the group consisting of ethoxylated fatty alcohols, polyethylene glycols, cellulose derivatives and mixtures thereof.

18. A bleaching composition incorporating a solid peroxyacid bleach precursor composition comprising a) particulate peroxyacid bleach precursor material, said precursor having a Mpt> 30°C and being selected from the group consisting of compounds containing at least one N-acyl group and compounds containing at least one O-acyl group, the external surfaces of said particulate bleach precursor material being treated with an organic acid compound so as to adhere said compound to said external surfaces, said acid compound being present in an amount of from about 2% to about 20% by weight of the treated particulate, said organic acid compound having an aqueous solubility of at least about 5g/100g of water at 20°C and a Mpt greater than about 30°C, wherein said treated particulate bleach precursor material produces, after 3 minutes in a Beaker Perhydrolysis Test at 20°C, at least about 90% of the peroxy acid that is produced under the same conditions by said particulate bleach precursor material in untreated form; and b) a granular inorganic perhydrate salt bleach.

19. A granular bleaching composition according to claim 18 wherein the perhydrate bleach is sodium perborate or sodium percarbonate, present as a dry-added granular material.

20. A granular bleaching detergent composition according to claim 19 further incorporating an organic surfactant selected from the group consisting of anionic, nonionic, cationic and ampholytic surfactants and mixtures thereof.

21. A granular bleaching detergent composition according to claim 20 wherein said surfactant is present as a component separate from said solid peroxyacid bleach precursor composition and said inorganic perhydrate, said component comprising particles of which no more than about 5% by weight have a particle size less than about 250 micro-meters.

22. A granular detergent bleaching composition according to claim 21 and having a bulk density of at least 650g/litre.