AU661681B2 - Peroxyacid bleach precursor compositions - Google Patents

Description

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OPI DATE 07/09/92 AOJP DATE 15/10/92 APPLN. In 14199 92 PCT NUMBER PCT/l1S92/nn664

INTER,

TREATY (PCT) (51) International Patent Classification 5 International Publication Number: WO 92/13798 C01B 15/00 Al C B 1500 Al. (43) International Publication Date: 20 August 1992 (20.08.92) (21) International Application Number: PCT/US92/00664 (81) Designated States: AT, AT (European patent), AU, BB, BE (European patent), BF (OAPI patent), BG, BJ (OAPI (22) International Filing Date: 28 January 1992 (28.01.92) patent), BR, CA, CF (OAPI patent), CG (OAPI patent), CH, CH (European patent), CI (OAPI patent), CM (OAPI patent), CS, DE, DE (European patent), DK, Priority data: DK (European patent), ES, ES (European patent), FI, 9102507.2 6 February 1991 (06.02.91) GB FR (European patent), GA (OAPI patent), GB, GB (European patent), GN (OA-I patent), GR (European patent), HU, IT (European patent), JP, KP, KR, LK, LU, (71) Applicant (for all designated States except US): THE PROC- LU (European patent), MC (European patent), MG, ML TER GAMBLE COMPANY [US/US]; One Procter (OAPI patent), MN, MR (OAPI patent), MW, NL, NL Gamble Plaza, Cincinnati, OH 45202 (European patent), NO, PL, RO, RU, SD, SE, SE (European patent), SN (OAPI patent), TD (OAPI patent), TG (72) Inventors; and (OAPI patent), US.

Inventors/Applicants (for US only) AGAR, Joseph, Thomas, Henry [GB/US]; 9 Severs Terrace, Callerton, Newcastle upon Tyne NE5 IPB FRASER, Douglas, Published Gilbert [GB/US]; 63 Bayswater Road, West Jesmond, With international search report.

Newcastle upon Tyne NE2 3HR Before the expiration of the time limit for amending the claims and to be republished in event of the receipt of (74) Agent: REED, David; The Procter Gamble Com- amendments.

pany, Ivorydale Technical Ctr., 5299 Spring Grove Avenue, Cincinnati, OH 45217-1087 (54) Title: PEROXYACID BLEACH PRECURSOR COMPOSITIONS (57) Abstract 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 The bleach precursor material, when so treated, perhydrolyses after 3 minutes in a standard test at 20 OC, 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.

jL.' j m I- 1:-I WO 92/13798 PCT/US92/00664 2 can give rise to significant localised peroxycarboxylate bleach concentrations.

The development of so-called concentrated products and their delivery via dispensing devices placed in the machine drum together with the fabric load has merely served to exacerbate these problems.

Accordingly a need exists to provide detergent compositions in which the bleach activator is incorporated in a form that minimises and preferably eliminates damage to fabric colours and materials during its dissolution and perhydrolysis in the wash liquor.

The prior art contains numerous examples of bleach activators coated or agglomerated so as to increase their stability on storage in detergent compositions and/or to influence their solution behaviour.

EP-A-0070474 discloses granulate bleach activators prepared by spray drying an aqueous pumpable dispersion containing an N-acyl or O-acyl compound together with at least one water soluble cellulose ether, starch or starch derivative in a weight ratio of activator to coating of from 98:2 to 90:10.

GB-A-1507312 discloses the coating of bleach activators with a mixture of alkali metal Cg C22 fatty acid salts in admixture with the corresponding fatty acids. GB-A-1381121 employs a molten coating of inter alia C14 C18 fatty acid mixtures to protect solid bleach activators. GB-A-1441416 discloses a similar process employing a mixture of C12 C14 fatty acids and C 1 0 aliphatic alcohols. EP-A-0375241 describes stabilised bleach activator extrudates in which C5- C18 alkyl peroxy carboxylic acid precursors are mixed with a binder selected from anionic and nonionic surfactants, film forming polymers fatty acids or mixtures I of such binders.

i EP-A-0356700 discloses compositions comprising a bleach activator, a water soluble film forming polymer and 2-15% of a C 3

-C

6 polyvalent carboxylic acid or hydroxycarboxylic acid for enhanced stability and ease of dispersion/solubility. The carboxylic acid, of WO 92/13798 PCT/US92/00664 which a preferred example is citric acid, is dry mixed with the bleach activator and then granulated with the film forming polymer.

The citric acid is asserted to provide an enhanced rate of dissolution of the bleach activator granules.

EP-A-0382464 concerns a process for coating or encapsulation of solid particles including bleaching compounds and bleach activators in which a melt is formed of coating material in which the particles 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 in the continuous (coating) phase. A variety of coating materials are disclosed and certain materials such as polyacrylic acid and cellulose acetate phthalate are taught as being useful where release of the coated material is dependent on pH.

The overall emphasis in the prior art has thus been on the protection of the bleach activator against a hostile environment during storage and relatively little attention has been paid to the dissolution characteristics of the coated or agglomerated material in use. Where coating and/or agglomeration has been proposed with poorly soluble materials such as fatty acids, this has resulted in a rate of perhydrolysis of the bleach activator which is slower than that which would occur if it had not been so protected. Any use of more rapidly soluble materials such as citric acid has been in the context of an agglomerate component in which more rapid solution of the bleach activator has been the objective. In both instances, because perhydrolysis commences as soon as the detergent product starts to dissolve and form an alkaline hydrogen peroxide solution the problem of localised peroxy acid bleach concentrations has remained unsolved.

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One solution to this problem wou perhydrolysis in order to avoid ti associated with the dissolution be components. However it is impo bleach precursor and subsequent ld be to delay the start of he fabric colour damage problems :haviour of other detergent product ,rtant that perhydrolysis of the dispersion of the peroxycarboxylate WO 92/13798 PCT/US92/00664 4 bleach is as rapid as possible when it commences because of the short wash times of moder 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 known that the rate of perhydrolysis of a percarboxylic acid bleach precursor in an aqueous oxidising medium is progressively reduced as the pH of the medium is reduced, particularly when the pH falls below the pKa of the parent acid of the precursor leaving group. However the fatty acids taught as coating agents in the prior art are not useful as a means of providing a low pH environment in an aqueous wash liquor because of their insolubility. Moreover fatty acids used as coating and/or agglomerating agents for peroxy acid bleach precursors have been found to reduce the rate of perhydrolysis of the latter, thereby reducing the effectiveness of the resultant peroxycarboxylic acid bleach.

The Applicant has now surprisingly found that acidic materials having certain specified characteristics can be used to provide a surface treatment to particulate peroxy acid bleach precursors, that delays the onset of perhydrolysis during dissolution of the product under the constrained agitation conditions of a loaded washing machine drum without adversely hindering perhydrolysis when it occurs.

According to the present invention there is provided a solid peroxyacid bleach precursor composition comprising a p culate peroxyacid bleach precursor material, said precurs containing one or more N- or 0- acyl groups and having a M 30 0 C, the external surfaces of said particulate per y acid bleach precursor material being treated with an ornic acid compound so as to adhere said compound to said exte surfaces, said compound being present in an amount rom 2% to 20% by weight of the treated Sparticulate, sai rganic acid compound having an aqueous solubility S of at leas g/100g of water at 20 0 C and a Mpt >30"C wherein sai eated particulate bleach precursor material produces, after 3 il N i Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives or components or integers.

According to the present invention there is provided a solid peroxyacid bleach precursor composition comprising a particulate peroxyacid bleach precursor material, said precursor containing one or more N- or 0- acyl groups and having a 0 C, 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 surfaces, said ccmpound being present in an amount of from 2% to 20% by weight of the treated particulate, said organic acid compound having an aqueous solubility of at least 5g/100g of water at 20 0 C and a Mpt>30 0

C,

wherein said treated particulate bleach precursor material produces, after 3

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i 11 _i WO 92/13798 PCT/US92/00664 minutes in a Beaker Perhydrolysis Test at 20°C, at least 90% of the peroxy acid that is produced under the same conditions by said particulate bleach precursor material in untreated form.

Preferably the organic acid compound is a monomeric or oligomeric carboxylate that has an aqueous solubility of at least 20g/100g of water at 20 0 C. Most preferably the compound is a monomeric aliphatic carboxylic acid of very high solubility and Mpt 40° C.

It is important for the purposes of the present invention that the external surfaces of the peroxy bleach precursor particulate, whether in the form of individual particles or agglomerates, are treated so that the organic acid compound is adhered thereto. The treatment can be such as to provide the compound in the form of a continuous or discontinuous coating or as masses of the acid compound dispersed on the particulate surface or as individual particles disposed at random on the surface. The requirement is that the surface treatment material be immediately available, on exposure to an aqueous medium, to dissolve rapidly and provide an acid pH environment around the exterior of the bleach precursor particulate.

For this reason, incorporation of the organic acid compound as an agglomerating agent dispersed within the peroxyacid bleach precursor particle does not provide the benefit of the invention. This is because, under the conditions of dissolution of a concentrated granular laundry product, particularly when delivered to washing machine drum by a dispensing device, an agglomerated but non surface treated peroxyacid bleach precursor perhydrolyses to a significant extent and generates high bleach concentrations that give i rise to localised fabric damage.

The solid peroxyacid bleach precursor compositions of the present invention incorporate precursors containing one or more N- or 0acyl groups, which precursors can be selected from a wide range of classes. Suitable classes include anhydrides, esters, imides and acylated derivatives of imidazoles and oximes, and examples of useful materials within these classes are disclosed in GB-A-1586789.

The most preferred classes are esters such as are disclosed in _i WO 92/13798 PCT/US92i00664 6 GB-A-836988, 864,798, 1147871 and 2143231 and imides such as are disclosed in GB-A-855735 1246338.

Specific O-acylated precursor compounds include 2,3,3-tri-methyl hexanoyl oxybenzene sulfonates, benzyl oxybenzene sulfonates and penta acetyl glucose.

Particularly preferred precursor compounds are the N-,N,N1N 1 tetra acetylated compounds of formula O O I I I CH3-C

C-CH

3 N-(CH2)x-N CH3.. C C-CH 3 O O wherein x can be O or an integer between 1 6.

Examples include tetra acetyl methylene diamine (TAMD) in which x= 1, tetra acetyl ethylene diamine (TAED) in which x =2 and tetraacetyl hexylene diamine (TAHD) in which x=6. These and analogous compounds are described in GB-A-907356. The most preferred peroxyacid bleach precursor is TAED.

Solid peroxyacid bleach precursors useful in the present invention have a Mpt 30 C and preferably 40 0 C. Such precursors will normally be in fine powder or crystalline form in which at least 90% by weight of the powder has a particle size 150 micrometers.

This powder can be surface treated directly but is more usually agglomerated, prior to surface treatment, to form particulate material, at Sleast 85% of which has a particle size between 400 and 1700 micrometers. Suitable agglomerating agents include C12-C1 8 fatty Iacids, C12-C18 aliphatic alcohols condensed with from 10 to 80 moles of ethylene oxide per mole of alcohol, cellulose derivatives such as methyl, I carboxymethyl and hydroxyethyl cellulose, polyethylene glycols of MWt 4,000 10,000 and polymeric materials such as polyvinyl pyrrolidone.

-r WO 92/13798 PCT/US92/00664 Agglomerated particulate precursor material does not itself provide the benefits of the invention but is a preferred form of the precursor to which the organic acid compound is applied as a surface treatment.

The organic acid compound must satisfy several criteria. Firstly it must be a solid at ambient temperatures and so must have a Melting Point of at least 30°C and preferably of at least 40°C. Preferred organic acid compounds will have a Melting Point in excess of 50 0

C.

Secondly the organic acid compound must be highly soluble in water at ambient temperatures, highly soluble being defined for the purposes of the present invention as at least 5g of the acid dissolving in 100g of distilled water at 20°C. Preferably the organic acid compound has a solubility of at least 20g/100g of water at 20 0 C and most preferably the organic acid compound will dissolve in its own weight of water at Thirdly the organic acid compound should have no more than a minor effect, and preferably substantially no effect, on the rate of perhydrolysis of the peroxyacid bleach precursor under well agitated unconstrained conditions. Unconstrained, well agitated conditions are defined for the purposes of the present invention as those existing in the Beaker Perhydrolysis Test described in detail hereinafter. A treatment material that has 'no more than a minor effect' on the rate of perhydrolysis of the precursor is defined, for the purposes of the present invention, as that which after 3 minutes in the Beaker Perhydrolysis Test at 20 0 C, permits the production of at least of the peroxyacid that is produced under the same conditions by the untreated bleach precursor material. Preferably the rates of perhydrolysis of treated and untreated material are substantially identical.

Organic acid compounds suitable as treating agents for the purposes of the present invention comprise aliphatic or aromatic monomeric or Soligomeric carboxylates and preferably comprise monomeric aliphatic carboxylic acids. Examples of such aliphatic acid

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i WO 92/13798 PCT/US92/00664 8 compounds are glycolic, glutamic, citraconic, succinic, 1-lactic and citric acids. The acids are applied at levels of from 2% to 20% by weight of the treated particulate, more preferably from 2% to and most preferably from 3 to 10% by weight of the treated particulate. Glycolic acid at a level of approximately 5 by weight of the treated particulate is a particularly preferred surface treating agent: The surface treatment of the bleach precursor particulate with the organic acid compound can be carried out in several ways and the process itself is not critical to the present invention.

The organic acid compound may be sprayed on as a molten material or as a solution or dispersion in a solvent/carrier liquid which is subsequently removed by evaporation. The organic acid compound can also be applied as a powder coating e.g. by electrostatic techniques although this is less preferred as the adherence of powdered coating material is more difficult to achieve and can be more expensive.

Molten coating is a preferred technique for organic acid compounds of Mpt 80'C such as glycolic and -lactic acids but is less convenient for higher Melting Point acids 100°C) such as citric acid. For organic acid compounds of Mpt> 80'C, spray on as a solution or dispersion is preferred. Organic solvents such as ethyl and isopropyl alcohol can be used to form the solutions or dispersions, although this will necessitate a solvent recovery stage in order to make their use economic. However, the use of organic 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 i acid compound has a high aqueous solubility citric acid) and the solution has a sufficiently low viscosity to enable it to be handled.

Preferably a concentration of at least 25% by weight of the organic acid compound in the solvent is used in order to reduce the -4 i WO 92/13798 PCT/US92/00664 9 drying/evaporation load after surface treatment has taken place. The treatment apparatus can be any of those normally used for this purpose, such as inclined rotary pans, rotary drums and fluidised beds.

Solid peroxyacid bleach precursor compositions in accordance with the invention can take a variety of physical forms. Thus the surface treated peroxyacid bleach precursor particles may themselves be incorporated into other solid compositions such as tablets, extrudates and agglomerates. The particulates can also be suspended in nonaqueous liquid compositions in which the organic acid surface treating material is insoluble and inert. However, the preferred application for the solid peroxybleach precursor compositions of the invention is as particulate components of granular detergent compositions, particularly the so-called concentrated detergent compositions that are added to a washing machine by means of a dosing device placed in the machine drum with the soiled fabric load.

Concentrated granular detergent compositions dispensed into the wash liquor via a dosing device are more subject to dissolution problems than compositions added via the dispensing compartment of a washing machine because, in the initial stages of a wash cycle, the agitation in the immediate environment of the product is inhibited by I the presence of the fabric load. Whilst this can constitute a benefit in permitting the development of high transient concentrations of builder and surfactant, the development of high transient peroxyacid concentrations can, as noted previously, lead to fabric and colour damage. The coated peroxyacid bleach precursor particulates of the present invention, when incorporated into concenti :Ated detergent products delivered to the wash liquor via a dispensing device, mitigate if not eliminate this problem.

Detergent compositions incorporating the surface treated peroxy acid bleach precursor particulates will normally contain from 0.5% to of the precursor, more frequeLtly from 1% to 8% and most preferably from 2% to on a composition weight basis.

11 ft WO 92/13798 PCT/US92/00664 Such detergent compositions will, of course, contain a source of alkaline hydrogen peroxide necessary to form a peroxyacid bleaching species in hst wash solution and preferably will also contain other components conventional in detergent compositions. Thus preferred detergent compositions will incorporate one of more of surfactants, organic and inorganic builders, soil suspending and anti-redeposition agents, suds suppressors, enzymes, fluorescent whitening agents photo activated bleaches, perfumes and colours.

Detergent compositions incorporating the surface treated particulate peroxyacid precursors of the present invention will include an inorganic perhydrate bleach, normally in the form of the sodium salt, as the source of alkaline hydrogen peroxide in the wash liquor. This perhydrate is normally incorporated at a level of from 3 to 22% by weight, more preferably from 5% to 20% by weight and most preferably from 8% to 18% by weight of the composition.

The perhydrate may be any of the inorganic salts such as perborate percarbonate, perphosphate and persilicate salts but is conventionally an alkali metal perborate or percarbonate. Whilst fabric colour damage arising from compositions in accordance with the invention is low, irrespective of whether a perborate or percarbonate salt is employed, the improvement in comparison with uncoated precursor particulates is more noticeable with percarbonate bleach as this causes greater fabric colour damage in the absence of any coating on the bleach precursor.

Sodium percarbonate, which is the preferred perhydrate, is an addition compound having a formula corresponding to 2Na2CO3.3H202, and is available commercially as a crystalline solid. Most commercially available material includes a low level of a heavy metal seques rant such as EDTA, 1-hydroxyethylidene 1, 1diphosphonic acid IEDP) or an amino-phosphonate, that is incorporated during .he manufacturing process. For the purposes of the detergent composition aspect of the present invention, the percarbonate can be incorporated into detergent compositions without additional protection, but preferred executions of such compositions c. WO 92/13798 PCT/US92/00664 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, preferably 2.8:1, applied as an aqueous solution to give a level of from 2% to 10%, (normally from 3 to of silicate solids y weight of the percarbonate. Magnesium silicate can also be included in the coating.

The particle size range of the crystalline percarbonate is from 350 micrometers to 450 micrometers with a mean of approximately 400 micrometers. When coated, the crystals have a size in the range from 400 to 600 micrometers.

Whilst heavy metals present in the sodium carbonate used to manufacture the percarbonate can be controlled by the inclusion of sequestrants in the reaction mixture, the percarbonate still requires protection from heavy metals present as impurities in other ingredients of the product. Accordingly, in detergent compositions utilising percarbonate as the perhydrate salt, the total level of Iron, Copper and Manganese ions in the product should not exceed ppm and preferably should be less than 20 ppm in order to avoid an unacceptably adverse effect on percarbonate stability. Detergent compositions in which alkali metal percarbonate bleach has enhanced stability are disclosed in the Applicants copending British Patent Application No. 9021761.3 (Attorney's Docket No. CM343).

A wide range of surfactants can be used in the detergent compositions. A typical listing of anionic, nonionic, ampholytic and zwitterionic classes, and species of these surfactants, is given in U.S.P. 3,929,678 issued to Laughlin and Heuring on December, 1975. A list of suitable cationic surfactants is given in U.S.P.

4,259,217 issued to Murphy on March 31, 1981.

Mixtures of anionic surfactants are suitable herein, particularly blends of sulphate, sulphonate and/or carboxylate surfactants.

Mixtures of sulphonate and sulphate surfactants are normally employed in a sulphonate to sulphate weight ratio of from 5:1 to 1:2, preferably from 3:1 to 2:3, more preferably from 3:1 to 1:1.

i 1 Our Ref: 335800 1925x

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WO 92/13798 PCIT/US92/00664 Preferred sulphonates include alkyl benzene sulphonates having from 9 to 15, especially 11 to 13 carbon atoms in the alkyl radical, and alpha-sulphonated methyl fatty acid esters in which the fatty acid is derived from a C12-C18 fatty source, preferably from a C16-C18 fatty source. In each instance the cation is an alkali metal, preferably sodium. Preferred sulphate surfactants in such sulphonate sulphate mixtures are alkyl sulphates having from 12 to 22, preferably 16 to 18 carbon atoms in the alkyl radical. Another useful surfactant system comprises a mixture of two alkyl sulphate materials whose respective mean chain lengths differ from each other. One such system comprises a mixture of C1 4 -C15 alkyl sulphate and C16-C18 alkyl sulphate in a weight ratio of C1 4 -C1 5 C16-C18 of from 3:1 to 1:1. The alkyl sulphates may also be combined with alkyl ethoxy sulphates having from 10 to 20, preferably 10 to 16 carbon atoms in the alkyl radical and an average degree of ethoxylation of 1 to 6. The cation in each instance is again an alkali metal, preferably sodium.

Other anionic surfactants suitable for the purposes of the invention are the alkali metal sarcosinates of formula R-CON CH2 COOM wherin R is.a C9-C17 linear or branched alkyl or alkenyl group, R' is a C 1

-C

4 alkyl group and M is an alkali metal ion. Preferred examples are the lauroyl, Cocoyl (C12-C14), myristyl and oleyl methyl sarcosinates in the form of their sodium salts.

One class of nonionic surfactants useful in the present invention comprises condensates of ethylene oxide with a hydrophobic moiety, providing surfactants having an average hydrophilic-lipophilic balance (HLB) in the range from 8 to 17, preferably from 9.5 to 13.5, more preferably from 10 to 12.5. The hydrophobic (lipophilic) moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

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=I Il l i i i .i i WO 92/13798 PCT/US92/00664 13 Especially preferred nonionic surfactants of this type are the C9-C primary alcohol ethoxylates containing 3-8 moles of ethylene oxide per mole of alcohol, particularly the C 14-C15 primary alcohols containing 6-8 moles of ethylene oxide per mole of alcohol and the C 12-C14 primary alcohols containing 3-5 moles of ethylene oxide per mole of alcohol.

Another class of nonionic surfactants comprises alkyl polyglucoside compounds of general formula RO (CnH2nO)tZx wherein Z is a moiety derived from glucose; R is a saturated hydrophobic alkyl group that contains from 12 to 18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.3 to 4, the compounds including less than 10% unreacted fatty alcohol and less than short chain alkyl polyglucosides. Compounds of this type and their use in detergent compositions are disclosed in EP-B 0070074, 0070077, 0075996 and 0094118.

A further class of surfactants are the semi-polar surfactants such as amine oxides. Suitable amine oxides are selected from mono preferably C10-C14 N-alkyl or alkenyl amine oxides and propylene-1,3-diamine dioxides wherein the remaining N positions are substituted by methyl, hydroxyethyl or hydroxpropyl groups.

Cationic surfactants can also be used in the detergent compositions herein and suitable quaternary ammonium surfactants are selected A. from mono C8-C16, preferably C10-C14 N-alkyl or alkenyl ammonium surfactants wherein remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

The detergent compositions comprise from 5% to 20% of surfactant but more usually comprise from 7% to 20%, more preferably from to 15 surfactant by weight of the compositions.

I c WO 92/13798 PCT/US92/00664 14 Combinations of surfactant types are preferred, more especially anionic-nonionic and also anionic-nonionic-cationic blends.

Particularly preferred combinations are described in GB-A-2040987 and EP-A-0087914. Although the surfactants can be incorporated into the compositions as mixtures, it is preferable to control the point of addition of each surfactant in order to optimise the physical characteristics of the composition and avoid processing problems.

Preferred modes and orders of surfactant addition are described hereinafter.

Another highly preferred component of detergent compositions incorporating the coated peroxy acid precursor particulates of the invention is a detergent builder system comprising one or more nonphosphate detergent builders. These can include, but are not restricted to alkali metal carbonates, bicarbonates, silicates, aluminosilicates, monomeric polycarboxylates, homo or copolymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxylic radicals separated from each other by not more than two carbon atoms, organic phosphonates and aminoalkylene poly (alkylene phosphonates) and mixtures of any of the foregoing. The builder system is present in an amount of from to 60% by weight of the composition, more preferably from to 60% by weight.

Preferred builder systems are free of boron compounds and any polymeric organic materials are preferably biodegradable.

Suitaile silicates are those having an SiO2:Na20 ratio in the range from 1.6 to 3.4, the so-called amorphous silicates of SiO2 ratios from 2.0 to 2.8 being preferred. These materials can be added at various points of the manufacturing process, such as in a slurry of components that are spray dried or in the form of an aqueous solution serving as an agglomerating agent for other solid components, or, where the silicates are themselves in particulate form, as solids to the other particulate components of the compositon. However, for compositions in which the percentage of compositon. However, for compositions in which the percentage of

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I EP-A-035670 0 discloses compositions comprising a bleach activator, I a water soluble film forming polymer and 2-15% of a C3-C6 polyvalent carboxylic acid or hydroxycarboxylic acid for enhanced stability and ease of dispersion/solubility. The carboxylic acid, of WO 92/13798 PCT/US92/00664 spray dried components is low i.e. 30%, it is preferred to include the amorphous silicate in the spray-dried components.

Within the silicate class, highly preferred materials are crystalline layered sodium silicates of general formula NaMSixO2x+ 1.yH20 wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20. Crystalline layered sodium silicates of this type are disclosed in EP-A-0164514 and methods for their preparation are disclosed in DE-A-3417649 and DE-A-3742043. For the purposes of the present invention, x in the general formule above has a value of 2, 3 or 4 and is preferably 2. More preferably M is sodium and y is 0 and preferred examples of this formula comprise the and b forms of Na2Si205. These materials are available from Hoechst AG FRG as respectively NaSKS-11 and NaSKS-6.

The most preferred material is -Na2Si205, (NaSKS-6).

Crystalline layered silicates are incorporated either as dry mixed solids, or as solid components of agglomerates with other components.

Whilst a range of aluminosilicate ion exchange materials can be used, preferred sodium aluminosilicate zeolites have the unit cell formula Naz [(A102 z (SiO2 )y xH wherein z and y are at least 6; the molar ratio of z to y is from 1.0 to and x is at least 5, preferably from 7.5 to 276, more preferably t from 10 to 264. The aluminosilicate materials are in hydrated form and are pr rably crystalline, containing from 10% to 28%, more preferably irom 18% to 22% water in bound form.

The above aluminosilicate ion exchange materials are further characterised by a particle size diameter of from 0.1 to micrometers, preferably from 0.2 to 4 micrometers. The term "particle size diameter" herein represents the average particle size diameter of a given ion exchange material as determined by conventional analytical techniques such as, for example, microscopic 1 associated with the dissolution behaviour of other detergent product components. However it is important that perhydrolysis of the i bleach precursor and subsequent dispersion of the peroxycarboxylate

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WO 92/13798 PCT/US92/00664 16 determination utilizing a scanning electron microscope or by means of a laser granulometer. The aluminosilicate ion exchange materials are further characterised by their calcium ion exchange capacity, which is at least 200 mg equivalent of CaCO3 water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which generally is in the range of from 300 mg eq./g to 352 mg eq./g. The aluminosilicate ion exchange materials herein are still further characterised by their calcium ion exchange rate which is at least 130 mg equivalent of CACO3/litre/minute/(g/litre) [2 grains Ca gallon/minute/gram/gallon)] of aluminosilicate (anhydrous basis), and which generally lies within the range of from 130 mg equivalent of CaCO3/litre/minute/(gram/litre) [2 grains/gallon/minute/ (gram/gallon)] to 390 mg equivalent of CaCO3/litre/minute/ (gram/litre) [6 grains/gallon/minute/(gram/gallon)], based on calcium ion hardness.

Optimum aluminosilicates for builder purposes exhibit a calcium ion exchange rate of at least 260 mg equivalent of CaCO3/litre/ minute/ (gram/litre) [4 grains/gallon/minute/(gram/gallon)].

Aluminosilicate ion exchange materials useful in the practice of this invention are commercially available and can be naturally occurring materials, but are preferably synthetically derived. A method for producing aluminosilicate ion exchange materials is discussed in US Patent No. 3,985,669. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material is Zeolite A and has the formula Na 12 [(A102 12 (Si02)12 xH2 0 wherein x is from 20 to 30, especially 27. Zeolite X of formula 1 Na86 [(A102)86(SiO2)106]. 276 H20 is also suitable, as well as SZeolite HS of formula Na6 [(A102)6(SiO2)6] 7.5 H2 O0).

i WO 92/13798 PCT/US92/00664 17 Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic acidity/constant (pK 1 of less than 9, preferably of between 2 and more preferably of between 4 and The logarithmic acidity constant is defined by reference to the equilibrium H+ A, 'H+A where A is the fully ionized carboxylate anion of the builder salt.

The equilibrium constant is therefore K1 A)

(A)

and pK 1 logl0K.

For the purposes of this specification, acidity constants are defined at C and at zero ionic strength. Literature values are taken where possible (see Stability Constants of Metal-Ion Complexex, Special Publication No. 25, The Chemical Society, London): where doubt arises they are determined by potentiometric titration using a glass electrode.

Preferred carboxylates can also be defined in terms of theic calcium ion stability constant (pKCa+ defined, analogously to pK1, by the equations pKCa++ loglOKCa++ Swhere KCa++ A)

(A)

Preferably, the polycarboxylate has a pK Ca+ in the range from about 2 to about 7 especially from about 3 to about 6. Once again iIi- WO 92/13798 PCT/US92/00664 18 literature values of stability constant are taken where possible. The stability constant is defined at 25 0 C and at zero ionic strength using a glass electrode method of measurement as described in Complexation in Analytical Chemistry by Anders Ringbom (1963).

The carboxylate or polycarboxylate builder can be momomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance.

Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates having the general formulae

Y

R

1 X C R 2 Z m

Y

Z

or Y Zq wherein R 1 represents H,C1-30 alkyl or alkenyl optionally substituted by hydroxy, carboxy, sulfo or phosphono groups or attached to a polyethylenoxy moiety containing up to 20 ethyleneoxy groups; R2 represents H,C1-4 alkyl, alkenyl or hydroxy alkyl, or alkaryl, sulfo, or phosphono groups; X represents a single bond; 0; S; SO; SO2; or NR 1 Y represents H; carboxy;hydroxy; carboxymethyloxy; or C1-30 alkyl or alkenyl optionally substituted by hydroxy or carboxy groups; Z represents H; or carboxy;

I

WO 92/13798 PCT/US92/00664 19 m is an integer from 1 to n is an integer from 3 to 6; p, q are integers from 0 to 6, p q being from 1 to 6; and wherein, X, Y, and Z each have the same or different representations when repeated in a given molecular formula, and wherein at least one Y or Z in a molecule contain a carboxyl group.

Suitable carboxylates containing one carboxy group include lactic acid, glycolic acid and ether derivatives thereof as disclosed in Belgian Patent Nos. 831,368, 821,369 and 821,370.

Polycarboxylates containing two carboxy groups include the watersoluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as the ether carboxylates described in German Offenlegenschrift 2,446,686, and 2,446,687 and U.S. Patent No.

3,935,257 and the sulfinyl carboxylates described in Belgian Patent No. 840,623. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates described in British Patent No.

1,379,241, lactoxysuccinates described in British Patent No.

1,389,732, and aminosuccinates described in Netherlands Application 7205873, and the oxypolycarboxylate materials such as 2-oxa-1,1,3-propane tricarboxylates described in British Patent No.

1,387,447.

Polycarboxylates containing four carboxy groups incldue oxydisuccinates disclosed in British Patent No. 1,261,829, 1,1,2,2ethane tetracarboxylates, 1,1,3,3-propane tetracarboxylates and 1,1,2,3-propane tetracarboxylates. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives disclosed in British Patent Nos. 1,398,421 and 1,398,422 and in U.S. Patent No.

3,936,448, and the sulfonated pyrolysed citrates described in British Patent No. 1,439,000.

Alicyclic and heterocyclic polycarboxylates include cyclopentanecis,cis,cis-tetracarboxylates, cyclopentadienide pentacarboxylates, i I WO 92/13798 PCT/US92/00664 2,3,4,5-tetrahydrofuran cis, cis, cis-tetracarboxylates, tetrahydrofuran cis dicarboxylates, 2,2,5,5-tetrahydrofuran tetracarboxylates, 1,2,3,4,5,6-hexane hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1,425,343.

Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, more particularly citrates.

The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as components of builder systems of detergent compositions in accordance with the present invention.

Other suitable water soluble organic salts are the homo- or copolymeric polycarboxylic 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-1,596,756.

Examples of such salts are polyacrylates of MWt 2000-5000 and their copolymers with maleic anhydride, such copolymers having a molecular weight of from 20,000 to 70,000, especially about 40,000.

These materials are normally used at levels of from 0.5% to 10% by weight more preferably from 0.75% to most preferably from 1% to 6% by weight of the composition.

Organic phosphonates and amino alkylene poly (alkylene phosphonates) include alkali metal ethane 1-hydroxy diphosphonates, nitrilo trimethylene phosphonates, ethylene diamine tetra methylene j phosphonates and diethylene triamine penta methylene phosphonates, although these materials are less preferred where the minimisation of I phosphorus compounds in the compositions is desired.

WO 92/13798 PCT/US92/00664 21 For the purposes of detergent compositions embodying the surface treated bleach precursor particulates of the invention the nonphosphate builder ingredient will comprise from 25% to 60% by weight of the compositions, 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 from 10% to 30% by weight of the total amount of builder and a crystalline layered silicate will comprise from 10% to 65% by weight of the total amount of builder. In such compositions the builder ingredient preferably also incorporates a combination of auxiliary inorganic and organic builders such as sodium carbonate and maleic anhydride/acrylic acid copolymers in amounts of up to by weight of the total builder.

Anti-redeposition and soil-suspension agents suitable herein include cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethycellulose, and homo-or co-polymeric polycarboxylic acids or their salts. Polymers of this type include copolymers of maleic anhydride with ethylene, methylvinyl ether or methacrylic acid, the maleic anhydride constituting at least 20 mole percent of the copolymer. These materials are normally used at levels of from to 10% by weight, more preferably from 0.75% to most preferably from 1% to 6% by weight of the composition.

Other useful polymeric materials are the polyethylene glycols, particularly those of molecular weight 1000-10000, 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 Sby weight. These polymers and the previously mentioned homo- or t co-polymeric polycarboxylate salts are valuable for improving whiteness maintenance, fabric ash deposition, and cleaning performance on clay, proteinaceous and oxidizable soils in the t presence of transition metal impurities.

Preferred optical brighteners are anionic in character, examples of which are disodium 4,4 1 -bis-(2-diethanolamino-4-anilino triazin- 1 WO 92/13798 PCT/US92/00664 22 6- ylamino)stilbene-2:2 1 disuiphonate, disodium 4,4 1 -bis-(2morpholino -4anilino-2-tr azin-6-ylaminostilbene-2 :21 disulphonate,di~odiumn 4, 41L ,4-dianilino-s-triazin-6ylamino)stilbene-2 :21 disuiphonate, monosodium. 41,411 -bis-(2,Adianilino-s-triazin-6 ylamino)stilbene-2- suiphonate, disodium 4,41 bis-(2-anilino-4-(N-methyl-N-2-hydroxyethylamino)-2-triazin-6ylamino)stilbene-2,2 1 disuiphonate, disodium 4,4 1 -bis-(4-phenyl- 2,1 ,3-triazol-2-yl)stilbene-2 ,2 1 disuiphonate, disodium 4 ,41bis(2anilino-4-(1-methyl-2-hydroxyethylamino)-s-triazin-6ylamino)stilbene-2 ,2 idisuiphonate and sodium 2(stilbyl4l 4:(naphtho-1l 1,2,3 triazole-2 1 sulphonate.

Soil-release agents useful in compositions of the present invention are conventionally copolymers or terpolymers of terephthalic acid with ethylene glycol and/or propylene glycol units in various arrangements. Examples of such polymers are disclosed in the commonly assigned US Patent Nos. 4116885 and 4711730 and European Published Patent Application No. 0272033. A particular I preferred polymer in accordance with EP-A-0272033 has the formula (cH 3 (PEG) 43 0 75

(PO)

0 25 CT-PO) 2 8(T-430.

4 T(PO-) 0 25 (EG) 43 CH 3 )0.75 where PEG in -(OC K)O-'PO Es (OC a 0) and T is (VCOC ECO).

Certain polymeric materials such as polyvinyl pyrrolidones typically of MWt 5000-20000, preferably 10000-15000, also form useful agents in preventing the transfer of labile dyestuffs between fabrics during the washing process.

Another optional detergent composition ingredient is a suds suppressor, exemplified by silicones, and silica-silicone mixtures.

Silicones can be generally represented by alkcylated polysiloxane materials while silica is normally used in finely divided forms, exemplified by silica aerogels and xerogels and hydrophobic silicas( of various types. These materials can be incorporated as particulates j in which the suds suppressor is advantageously releasably incorporated in a water-soluble or water-dispersible, substantiallyI WO 92/13798 PCT/US92/00664 23 non-surface-active detergent-impermeable carrier. Alternatively the suds suppressor can be dissolved or dispersed in a liquid carrier and applied by spraying on to one or more of the other components.

As mentioned above, useful silicone suds controlling agents can comprise a mixture of an alkylated siloxane, of the type referred to hereinbefore, and solid silica. Such mixtures are prepared by affixing the silicone to the surface of the solid silica. A preferred silicone suds controlling agent is represented by a hydrophobic silanated (most preferably trimethyl-silanated) silica having a particle size in the range from 10 nanometers to 20 nanometers and a specific surface area above 50 m 2 intimately admixed with dimethyl silicone fluid having a molecular weight in the range from about 500 to about 200,000 at a weight ratio of silicone to silanated silica of from about 1:1 to about 1:2.

A preferred silicone suds controlling agent is disclosed in Bartollota et al. US Patent 3,933,672. Other particularly useful suds suppressors are the self-emulsifying silicone suds suppressors, described in German Patent Application DTOS 2,646,126 published April 28, 1977. An example of such a compound is DC0544, commercially available from Dow Coming, which is a siloxane/glycol copolymer.

The suds suppressors described above are normally employed at levels of from 0.001% to 0.5% by weight of the composition, preferably from 0.01% to 0.1% by weight.

The preferred methods of incorporation comprise either application of the suds suppressors in liquid form by spray-on to one or more of the major components of the composition or alternatively the formation of the suds suppressors into separate particulates that can then be mixed with the other solid components of the composition.

The incorporation of the suds modifiers as separate particulates also permits the inclusion therein of other suds controlling materials such as C20-C24 fatty acids, microcrystalline waxes and high MWt copolymers of ethylene oxide and propylene oxide which would WO 92/13798 PCT/US92/00664 24 otherwise adversely affect the dispersibility of the matrix.

Techniques for forming such suds modifying particulates are disclosed in the previously mentioned Bartolotta et al US Patent No.

3,933,672.

Another optional ingredient useful in the present invention is one or more enzymes.

Preferred enzymatic materials include the commercially available amylases, neutral and alkaline proteases, lipases, esterases and cellulases conventionally incorporated into detergent compositions.

Suitable enzymes are discussed in US Patents 3,519,570 and 3,533,139.

Fabric softening agents can also be incorporated into detergent compositions in accordance with the present invention. These agents may be inorganic or organic in type. Inorganic softening agents are examplified by the smectite clays disclosed in GB-A-1,400,898.

Organic fabric softening agents include the water insoluble tertiary amines as disclosed in GB-A-1514276 and EP-B-0011340.

Their combination with mono C12-C1 4 quaternary ammonium salts is disclosed in EP-B-0026527 528. Other useful organ r r 'jric softening agents are the dilong chain amides as disclr -J in EP-B- 0242919. Additional organic ingredients of fabric softening systems include high molecular weight polyethylene oxide materials as disclosed in EP-A-0299575 and 0313146.

Levels of smectite clay are normally in the range from 5% to 15 more preferably from 8 to 12% by weight, with the material being added as a dry mixed component to the remainder of the formulation.

Organic fabric softening agents such as the water-insoluble tertiary amines or dilong chain amide materials are incorporated at levels of from 0.5% to 5% by weight, normally from 1% to 3 by weight, whilst the high molecular weight polyethylene oxide materials and the water soluble cationic materials are added at levels of from 0.1% to normally from 0.15% to 1.5% by weight. Where a portion i. WO 92/13798 PCT/US92/00664 of the composition is spray dried, these materials can be added to the aqueous slurry fed to the spray drying tower, although in some instances it may be more convenient to add them as a dry mixed particulate, or spray them as a molten liquid on to other solid components of the composition.

The surface treated peroxyacid bleach precursor particulates of the present invention are particularly useful in concentrated granular detergent compositions that are characterised by a relatively high density in comparison with conventional laundry detergent compositions. Such high density compositions have a bulk density of at least 650 g/litre, more usually at least 700 g/litre and more preferably in excess of 800 g/litre.

Bulk density is measured by means of a simple funnel and cup device consisting of a conical funnel moulded rigidly on a base and provided with a flap valve at its lower extremity to allow the contents of the funnel to be emptied into an axially aligned cylindrical cup disposed below the funnel. The funnel is 130 mm and 40 mm at its respective upper and lower extremities. It is mounted so that the lower extremity is 140 mm above the upper surface of the base. The cup has an overall height of 90 mm, an internal height of 87 mm and an internal diameter of 84 mm. Its nominal volume is 500 ml.

To carry out a measurement, the hand pouring, the flap valve is o overfill the cup. The filled cup i excess powder removed from th implement e.g. a knife, across it weighed and the value obtained f provide the bulk density in g/litr as required.

Concentrated detergent composit least one multi-ingredient compo compositions formed merely by Compositions in which each indi funnel is filled with powder by pened and powder allowed to s removed from the frame and e cup by passing a straight edged s upper edge. The filled cup is then or the weight of powder doubled to e. Replicate measurements are made ions also normally incorporate at nent i.e. they do not comprise dry-mixing individual ingredients.

vidual ingredient is dry-mixed are WO 92/13798 PCT/US92/00664 26 generally dusty, slow to dissolve and also tend to cake and develop poor particle flow characteristics in storage.

Subject to the above bulk density and component content limitations, the compositions of the invention can be made via a variety of methods including dry mixing, spray drying, agglomeration and granulation and preferred methods involve combinations of these techniques. A preferred method of making the compositions involves a combination of spray drying, agglomeration in a high speed mixer and dry mixing.

Preferred detergent compositions in accordance with the invention comprise at least two particulate multi-ingredient components. The first component comprises at least 15 conventionally from 25 to but more preferably no more than 35 by weight of the composition and the second component from 1 to 50%, more preferably 10% to 40% by weight of the composition.

The first component comprises a particulate incorporating an anionic surfactant ii an amount of from 0.75% to 40% by weight of the powder and one or more inorganic and/or organic salts in an amount of from 99.25% to 60% by weight of the powder. The particulate can have any suitable form such as granules, flakes, prills, marumes or noodles but is preferably granular. The granules themselves may be agglomerates formed by pan or drum agglomeration or by in-line mixers but are customarily spray dried particles produced by a atomising an aqueous slurry of the ingredients in a hot air stream which removes most of the water. The spray dried granules are then subjected to densification steps, e.g. by high speed cutter mixers and/or compacting mills, to increase density before being reagglomerated. For illustrative purposes, the first component is described hereinafter as a spray dried powder.

Suitable anionic surfactants for the purposes of the first component have been found to be slowly dissolving linear alkyl sulfate salts in which the alkyl group has an average of from 16 to 22 carbon atoms, and linear alkyl carboxylate salts in which the alkyl group has an c I- WO 92/13798 PCT/US92/00664 27 average of from 16 to 24 carbon atoms. The alkyl groups for both types of surfactant are preferably derived from natural sources such as tallow fat and marine oils.

The level of anionic surfactant in the spray dried powder forming the first component is from 0.75% to 40% by weight, more usually to 25% preferably from 3% to 20% and most preferably from to 15 by weight. Water-soluble surfactants such as linear alkyl benzene sulphonates or C 14 -C15 alkyl sulphates can be included or alternatively may be applied subsequently to the spray dried powder by spray on.

The other major ingredient of the spray dried powder is one or more inorganic or organic salts that provide the crystalline structure for the granules. The inorganic and/or organic salts may be watersoluble or water-insoluble, the latter type being comprised by the, or the major part of the, water-insoluble builders where these form part of the builder ingredient. Suitable water soluble inorganic salts include the alkali metal carbonates and bicarbonates. Alkali metal silicates other than crystalline layered silicates can also be present in the spray dried granule provided that aluminosilicate does not form part of the spray dried component.

However, in concentrated detergent compositions 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.

Preferably no sodium sulphate is added as a separate ingredient and its incorporation as a by-product e.g. with sulph(on)ated surfactants, should be minimised.

Where an aluminosilicate zeolite forms the, or part of the, builder ingredient, it is preferred that it is not added directly by dry-mixing to the other components, but is incorporated into the multi-ingredient component(s). Where incorporation of the zeolite takes place in the Sspray-dried granule, any silicate present should not form part of the Sspray-dried granule. In these circumstances, incorporation of the silicate can be achieved in several ways, e.g. by producing a separate 1 ij WO 92/13798 PCT/US92/00664 28 silicate-containing spray-dried particulate, by incorporating the silicate into an agglomerate of other ingredients, or more preferably by adding the silicate as a dry mixed solid ingredient.

The first component can also include up to 15% by weight of miscellaneous ingredients such as brighteners, anti-redeposition agents, photoactivated bleaches (such as tetrasulfonated zinc phthalocyanine) and heavy metal sequestering agents. Where the first component is a spray dried powder it will normally be dried to a moisture content of from 7% to 11% by weight, more preferably from 8% to 10% by weight of the spray dried powder. Moisture contents of powders produced by other processes such as agglomeration may bc lower and can be in the range 1-10% by weight.

The particle size of the first component is conventional and preferably not more than 5% by weight should be above 1.4mm, while not more than 10% by weight should be less than 0.15 mm in maximum dimension. Preferably at least 60%, and most preferably at least 80%, by weight of the powder lies between 0.7 mm and 0.25 mm in size. For spray dried powders, the bulk density of the particles from the spray drying tower is conventionally in the range from 540 to 600 g/litre and this is then enhanced by further processing steps such as size reduction in a high speed cutter/mixer followed by compaction. Alternatively, processes other than spray drying may be used to form a high density particulate directly.

A second component of a preferred composition in accordance with the invention is another multi-ingredient particulate containing a water soluble surfactant.

This may be anionic, nonionic, cationic or semipolar in type or a mixture of any of these. Suitable surfactants are listed hereinbefore but preferred surfactants are C14-C15 alkyl sulphates, linear C11alkyl benzene sulphonates and fatty C14-C18 methyl ester sulphonates.

J"

1 i_ c i. l WO 92/13798 PCT/US92/00664 29 The second component may have any suitable physical form, i.e. it may take the form of flakes, prills, marumes, noodles, ribbons, or granules which may be spray-dried or non spray-dried agglomerates.

Although the second component could in theory comprise the water soluble surfactant on its own, in practice at least one organic or inorganic salt is included to facilitate processing. This provides a degree of crystallinity, and hence acceptable flow characteristics, to the particulate and may be any one or more of the organic or inorganic salts present in the first component.

The particle size range of the second component should be such as to obviate segregation from the particles of the first component when blended therewith. Thus not more than 5% by weight should be above 1.4 mm while not more than 10% should be less than 0.15 mm in maximum dimension.

The bulk density of the second component will be a function of its mode of preparation. However, the preferred form of the second component is a mechanically mixed agglomerate which may be made by adding the ingredients dry or with an agglomerating agent to a pan agglomerator, Z blade mixer or more preferably an in-line mixer such as those manufactured by Schugi (Holland) BV, 29 Chroomstraat 8211 AS, Lelystad, Netherlands and Gebruder Lodige Maschinenbau GmbH, D-4790 Paderborn 1, Elsenerstrasse 7-9, Postfach 2050 F.R.G. By this means the second component can be given a bulk density in 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 component corresponding to an amount of from 3 to by weight of the composition, more preferably from 5% to 12% I by weight. This will provide a level of carbonate in the second j component of from 20% to 40% by weight.

t A highly preferred ingredient of the second component is also a 7 hydrated water insoluble aluminosilicate ion exchange material of the 1 synthetic zeolite type, described hereinbefore, present at from WO 92/13798 PCT/US92/00664 to 35% by weight of the second component. The amount of water insoluble aluminosilicate material incorporated in this way is from 1% to 10% by weight of the composition, more preferably from 2% to 8% by weight.

In one process for preparing the second component, the surfactant salt is formed in situ in an inline mixer. The liquid acid form of the surfactant is added to a mixture of particulate anhydrous sodium carbonate and hydrated sodium aluminosilicate in a continuous high speed blender, such as a Lodige KM mixer, and neutralised to form the surfactant salt whilst maintaining the particulate nature of the mixture. The resultant agglomerated mixture forms the second component which is then added to other components of the product.

In a variant of this process, the surfactant salt is pre-neutralised and added as a viscous paste to the mixture of the other ingredients. In the variant, the mixer serves merely to agglomerate the ingredients to form the second component.

In a particularly preferred process for making detergent compositions incorporating the coated peroxyacid bleach precursor particulates of the invention, part of the spray dried product comprising the first granular component is diverted and subjected to a low level of nonionic surfactant spray on before being reblended with the remainder. The second granular component is made using the preferred process described above. The first and second components together with the coated bleach precursor particulate and the r.3 perhydrate bleach, other dry mix ingredients such as any carboxylate chelating agent, soil-release polymer, silicate of conventional or crystalline layered type, and enzyme are then fed to a conveyor belt, i from which they are transferred to a horizontally rotating drum in which perfume and silicone suds suppressor are sprayed on to the product. In highly preferred compositions, a further drum mixing step is employed in which a low (approx. 2% by weight) level of finely divided crystalline material is introduced to increase density and improve granular flow characteristics.

WO 92/13798 PCT/US92/00664 31 In preferred concentrated detergent products incorporating an alkali metal percarbonate as the perhydrate salt it has been found necessary to control several aspects of the product such as its heavy metal ion content and its equilibrium relative humidity. Sodium percarbonatecontaining compositions of this type having enhanced stability are disclosed in the commonly assigned British Application No.

9021761.3 filed October 6 1990 Attorney's Docket No. CM343.

Compositions in accordance with the invention can also benefit from delivery systems that provide transient localised high concentrations of product in the drum of an automatic washing machine at the start of the wash cycle, thereby also avoiding problems associated with loss of product in the pipework or sump of the machine.

Delivery to the drum can most easily be achieved by incorporation of the composition in a bag or container from which it is rapidly releasable at the start of the wash cycle in response to agitation, a rise in temperature or immersion in the wash water in the drum.

Alternatively the washing machine itself may be adapted to permit direct addition of the composition to the drum e.g. by a dispensing arrangement in the access door.

Products comprising a detergent composition enclosed in a bag or container are usually designed in such a way that container integrity is maintained in the dry state to prevent egress of the contents when dry, but are adapted for release of the container contents on exposure to a washing environment, normally on immersion in an aqueous solution.

Usually the container will be flexible, such as a bag or pouch. The bag may be of fibrous construction coated with a water impermeable protective material so as to retain the contents, such as is disclosed in European published Patent Application No. 0018678. Alternatively it may be formed of a water-insoluble synthetic polymeric material provided with an edge seal or closure designed to rupture in aqueous media as disclosed in European published Patent Application Nos.

0011500, 0011501, 0011502, and 0011968. A convenient form of N WO 92/13798 PCT/US92/00664 32 water frangible closure comprises a water soluble adhesive disposed along and sealing one edge of a pouch formed of a water impermeable polymeric film such as polyethylene or polypropylene.

In a variant of the bag or container form, laminated sheet piroducts can be employed in which a central flexible layer is impregnated and/or coated with a composition and then one or more outer layers are applied to produce a fabric-like aesthetic effect. The layers may be sealed together so as to remain attacked during use or may separate on contact with water to facilitate the release of the coated or impregnated material.

An alternative laminate form comprises one layer embossed or deformed to provide a series of pouch-like containers into each of which the detergent components are deposited in measured amounts, with a second layer overlying the first layer and sealed thereto in those areas beteen the pouch-like containers where the two layers are in contact. The components may be deposited in particulate, paste or molten form and the laminate layers should prevent egress of the contents of the pouch-like containers prior to their addition to water.

The layers may separate or may remain attached together on contact with water, the only requirement being that the structure should permit rapid release of th1e contents of the pouch-like containers into solution. The number of pouch-like containers per unit area of substrate is a matter of choice but will normally vary between 500 and 25,000 per square metre.

Suitable materials which can be used for the flexible laminate layers in this aspect of the invention include, among others, sponges, paper and woven and non-woven fabrics.

However the preferred means of carrying out the process of the invention is to introduce the composition into the liquid surrounding the fabrics that are in the drum via a reusable dispensing device having walls that are permeable to liquid but impermeable to the solid composition.

i_ WO 92/13798 PCT/US92/00664 33 Devices of this kind are disclosed in European Patent Application Publication Nos. 0343069 0343070. The latter Application discloses a device comprising a flexible sheath in the form of a bag extending from a support ring defining an orifice, the orifice being adapted to admit to the bag sufficent product for one washing cycle in a washing cycle. A portion of the washing medium flows through the orifice into the bag, dissolves the product, and the solution then passes outwardly through the orifice into the washing medium. The support ring is provided with a masking arrangement to prevent egress of wetted, undissolved, product, this arrangement typically comprising radially extending walls extending from a central boss in a spoked wheel configuration, or a similar structure in which the walls have a helical form.

The invention is illustrated in the following non limiting Examples, in which all percentages are on a weight basis unless otherwise stated.

I

i I

-I

WO 92/13798 PCT/US92/00664 34 In the detergent compositions, the abbreviated component identifications have the following meanings:

C

12 LAS Sodium linear C 12 alkyl benzene sulphonate TAS Sodium tallow alcohol sulphate C14/15AS Sodium C 14

-C

15 alkyl sulphate TAEn Tallow alcohol ethoxylated with n moles of ethylene oxide per mole of alcohol 45E7 A C 14 -1 5 predominantly linear primary alcohol condensed with an average of 7 moles of ethylene oxide A C 1 2-C 13 primary alcohol condensed with moles of ethylene oxide.

PEG Polyethylene glycol (MWt normally follows) TAED Tetraacetyl ethylene diamine Silicate Amorphous Sodium Silicate (SiO 2 :Na20 ratio normally follows) NaSKS-6 Crystalline layered silicate of formula Na 2 Si 2 Carbonate Anhydrous sodium carbonate CMC Sodium carboxymethyl cellulose Zeolite A Hydrated Sodium Aluminosilicate of formula Nal 2 (A10 2 SiO 2 12 27H 2 0 having a primary particle size in the range from 1 to 10 micrometers Polyacrylate Homopolymer of acrylic acid of MWt 4000 Citrate Tri-sodium citrate dihydrate WO 92/13798 PCT/US92/00664 Photoactivated Bleach

MA/AA

MVEMA

Perborate Perborate Monohydrate Percarbonate Enzyme Brightener

DETPMP

Mixed Suds Suppressor Tetra sulphonated Zinc phthalocyanine Copolymer of 1:4 maleic/acrylic acid, average molecular weight about 80,000.

Maleic anhydride/vinyl methyl ether copolymer, believed to have an average molecular weight of 240,000. This material was prehydrolysed with NaOH before addition.

Sodium perborate tetrahydrate of nominal formula NaBO2.3H20.H 2 0 2 Anhydrous sodium perborate bleach empirical formula NaBO2.H202 Sodium Percarbonate of nominal formula 2Na2CO3.3H202 Mixed proteolytic and amylolytic enzyme sold by Novo Industries AS.

Disodium 4,4'-bis(2-morpholino-4-anilinos-triazin-6-ylamino) stilbene-2:2'disulphonate.

Diethylene triamine penta (Methylene phosphonic acid), marketed by Monsanto under the Trade name Dequest 2060 25% paraffin wax Mpt 50 0 C, 17% hydrophobic silica, 58% paraffin oil.

WO 92/13798 PCT/US92/00664 36 For the purpose of the present invention, unrestrained dissolution conditions are defined as those existing in the Beaker Perhydrolysis Test as carried out using a Sotax Dissolution Tester Model AT6 supplied by Sotax AG CH-4008 BASEL Switzerland. This Apparatus comprises an array of polycarbonate beakers, each capable of holding 1 litre of water, supported in a thermostatically controlled water bath. Each beaker is provided with a paddle stirrer whose speed can be controlled.

Two beakers in the Sotax Tester are employed in the perhydrolysis procedure using the following method: 1. Set water bath to required temperature 2. Add I litre distilled water to each Sotax beaker and allow to equilibrate to required temperature.

3. Sample accurately 2 x 10g samples of detergent and precursor.

4. Prepare a number of titration beakers by adding: ml 3:2 glacial acetic acid distilled water solution together with 2 ice cubes Set the stirring speed of the Sotax to 150 rpm.

6. Add the first sample to Sotax beaker No. 1 and start the clock (t=O minutes). Add 5 ml potassium iodide solution to the first titration beaker.

7. Take a 10 ml aliquot from Sotax beaker No. 1 and discharge into the first titration beaker at t 1 minute.

8. Add the second sample to Sotax beaker No. 2 at t 1 minute and add 5 ml potassium iodide to a second titration beaker.

9. Titrate the first aliquot against 0.005 m sodium thiosulphate solution until the solution is first decolourised (The colour is slowly regenerated as the solution warms and the perhydrate reacts with the iodide).

Take a 10 ml aliquot from Sotax beaker No. 2 at t 2 minutes and discharge into the second titration beaker and repeat step 9.

11. Take further aliquots at the following times (t minutes) i I A WO 92/13798 PCr/US92/00664 Beaker No. 1 (t) 3 Beaker No. 2 (t) 4 6 11 16 21 The aliquots from Beaker No. 1 at 1 minute and from Beaker No. 2 at 2 minutes constitute replicates and the results are averaged to give a figure from which the perhydrolysis is calculated.

Example 1 TAED in fine powder form (particle size 90% by weight 150 micrometers), was agglomerated with TAE25 to give particles in which 85% by weight was between 400 micrometers and 1700 micrometers. This material was divided into five fractions identified as A-F, of which fraction A was untreated and the remainder were treated as follows Surface Treating Material octanoic acid polyacrylic acid (MWt 2,000) glycolic acid citric acid The treatments were all applied by hand spraying into a small coating drum. The octanoic acid was applied as a melt at 60 0 C whilst the remainder were applied as aqueous solutions at ambient temperature 0 The citric acid solution was 50% by weight, the glycolic acid solution was 66% by weight and the polyacrylic acid solution was 50% by weight.

i WO 92/13798 PCT/US92/00664 38 Material from each fraction was then incorporated into a model detergent formulation having the composition in parts by weight.

C12LAS TAS Z.8 Dobanol 45E7 3.8 Zeolite A 23.5 Citrate MA/AA 3.75 Carbonate 17.0 Silicate 4.2 (SiO2:Na20=2:1) DETPMP 0.4 CMC Percarbonate 18.7 TAED 5.85 Miscellaneous 3.00 The five formulations were then subjected to a Beaker Perhydrolysis Test as hereinbefore described and gave the peroxyacid yields shown in Table 1 Results are given for 1,3,5,10 15 20 minutes elapsed time and are expressed in percent of the theoretically available weight of per acid.

Table I minutes from start of perhydrolysis Product with TAED fraction 1 3 5 10 15 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 C 29.0 67.2 77.2 88.2 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 the fractions D E give substantially the same peroxyacid yield as that containing fraction A, (both after 3 minutes and throughout the perhydrolysis reaction), 39 indicating that the perhydrolysis under unconstrained dissolution conditions was suVbtantially unaffected by the treatment By contrast formulations containing fractions B C showed a lower peroxy acid yield, particularly in the initial period of the perhydrolysis.

Exanile2 The formulations containg TAED fractions A D of Example 1 were subjected to a full scale washing machine test using Miele automatic washing machines (Model W754) set to the Short Wash cycle at 40 0 C. Each machine was loaded with four cotton bedsheets (3.3 kg) and 100g of the formulation was added to the fabrics in the machine drum via an Arielator (RTM) dispensing device. 12 litres of water of 150 ppm hardness (expressed as CCO 3 with a Ca:Mg ratio of 3:1 was fed to each machine.

Two machines, adapted to allow cpening of the loading door during the cycle for sampling purposes, were used to carry out 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 Table II minutes from start of wash cycle Product with TAED fraction 1 3 5 10 15 A 31.5 56.1 82.1 92.1 89.4 89.4 D 9.1 50.6 68.0 99.5 98.5 96.7 It can be seen that, under the constrained dissolution conditions of a loaded washing machine, the product containing fraction D (the glycolic acid-surface treated TAED), perhydrolyses more slowly than the product containing fraction A (the untreated material), during the initial stages of the wash cycle. This shows that the glycolic acid surface treatment of the TAED inhibits perhydrolysis during the period of high localised product concentration existing at the start of the wash cycle, where the high aqueous solubility of the acid is believed to create a low pH environment around the TAED WO 92/13798 PCT/US92/00664 particles. Nevertheless, in the later stages of the wash cycle, the yield of peroxy acid from the treated TAED is better than from the untreated material, indicating that delayed release of the TAED results in its more effective conversion into peroxy acid.

Example 3 A full scale washing machine test was carried out comparing three formulations containing fractions B, C D of the surface treated precursor of Example 1. The fractions were added respectively to a modified form of the detergent formulation of Example 1 in which the sodium percarbonate was replaced by the same weight of sodium perborate monohydrate.

The washing machine comparison employed the same technique as that used in Example 2, save that the wash temperature was This temperature is typical of that found during the initial cold fill stage of European wash cycles. Results are shown below in Table

III

Table III minutes from start of wash cycle Formulation with fraction 1 3 5 10 15 B 4.6 33.6 54.7 74.8 78.0 80.3 C 4.6 32.6 54.3 80.7 84.8 88.0 D 3.65 54.8 70.8 83.0 88.5 85.0 This shows that a peroxy acid bleach precursor surface treated in AN accordance with the invention provides superior yields of peroxy acid under realistic washing conditions, compared to surface treatment precursors that are not in accordance with the invention.

Example IV A washing machine comparison of formulations similar to that carried out in Example III and incorporating precursor fractions A,B, C E was carried out to include bleach-sensitive coloured fabric swatches in the fabric load. These swatches were made of ij WO 92/13798 PCT/US92/00664 41 100% lambswool woven fabric with purple 48 dye (Design No.

W3970) supplied by Borval Fabrics, Albert Street, Huddersfield, West Yorkshire, England. 24 repi:cates of each treatment were performed and the swatches were then graded visually for fabric colour damage by an expert panel using the following grading system.

Three coloured swatches demonstrating differing degrees of colour damage are used as standards to establish a 4 point scale in which 1 represents 'virtually no damage' and 4 represents 'very damaged'.

The three standards are used to define the mid points between the various descriptions of colour damage viz 1 virtually no damage 2 slight damage 3 damage 4 very damaged Two expert panellists are used and their results are averaged.

Using this technique to compare colour damage resulting from use of formulations containing precursor fractions A,B,C E the following results were obtained of swatches having grade formulation with Overall precursor fraction 1 2 3 4 Grade A 50 29.2 8.33 12.5 1.83 B 52.2 26.1 21.7 0 1.70 C 47.8 30.4 17.4 4.4 1.78 E 66.6 16.6 10.5 6.2 1.56 It can be seen that a formulation incorporating fraction E in accordance with the invention produces appreciably less fabric colour damage than non surface treated precursor or surface treated precursors not in accordance with the invention.

WO 92/13798 PCT/US92/00664 42 Example V The washing machine comparison of Example IV was repeated using formulations containing TAED fractions A D of Example 1, as well as an additional TAED fraction F comprising fraction A further agglomerated with 10% by weight of glycolic acid (on total agglomerate weight basis). The formulations were subjected to a coloured swatch degradation test as described in Example IV and gave the following results of swatches having grade Overall 1 2 3 4 Grade A 16 20 25 38 2.83 D 29 38 29 4 2.08 F 9 35 35 22 2.70 It can be seen that fraction D, incorporating 5% glycolic acid surface treated precursor particulates in accordance with the invention, has a markedly lower overall damage grade thain 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 untreated material. This confirms the importance of surface treatment of the bleach precursor particulates in obtaining the fabric damage reduction benefit of the invention.

i i

A

Claims (18)

1. A solid peroxyacid bleach precursor composition comprising a particulate peroxyacid bleach precursor material, said precursor containing one or more N- or 0- acyl groups and having a Mpt> 30 0 C, 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 2% to 20% by weight of the treated particulate, said organic acid compound having an aqueous solubility of at least 5g/100g of water at 20°C and a Mpt> 30 0 C wherein said treated particulate bleach precursor material produces, after 3 minutes in a Beaker Perhydrolysis Test at 20 0 C, at least 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 20g/100g of water at

3. A solid peroxyacid bleach precursor composition according to either one of claims 1 2 wherein the organic acid compound is a monomeric or oligomeric carboxyjlate.

4. A solid peroxyacid bleach precursor composition according to any one of claims 1-3 wherein the organic acid compound is a monomeric aliphatic carboxylic acid having a MPt >40 0 C. A solid peroxyacid bleach precursor composition according to any one of claims 1-4 wherein the organic acid compound is selected from glycolic, I-lactic and and citric acids.

6. A solid bleach peroxyacid precursor composition according to J any one of claims 1-5 wherein the amount of treating material is from 2% to 15% by weight of the composition. I I WO 92/13798 PCT/US92/00664

7. A solid peroxyacid bleach precursor composition according to any one of claims 1-6 wherein the amount of treating material is from 3% to 10% by weight of the composition.

8. A solid peroxyacid bleach precursor composition according to any one of claims 5-7 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.

9. A solid peroxyacid bleach precursor composition according to any one of claims 1-8 wherein the peroxyacid bleach precursor contains at least one N-diacyl moiety. A solid peroxyacid bleach precursor composition according to any one of claims 1-9 wherein the peroxyacid bleach precursor is a tetraacylated alkylenediamine.

11. A solid peroxyacid bleach precursor composition according to any one of claims 1-10 wherein the peroxyacid bleach precursor is tetraacetyl ethylenediamine.

12. A solid peroxyacid bleach precursor composition according to any one of claims 1-11 wherein the particulate precursor material comprises agglomerated particles of the precursor, the agglomerated particles being treated with the organic acid compound.

13. A solid peroxyacid bleach precursor composition according to claim 12 wherein the agglomerating agent is selected from ethoxylated fatty alcohols, polyethylene glycols and cellulose derivatives. WO 92/13798 PCT/US92/00664

14. A solid peroxyacid bleach precursor composition according to any one of claims 1-13 wherein particulate peroxyacid bleach precursor material is treated with a molten organic acid compound to provide a coating to the external surfaces of the particulate bleach precursor material. A solid peroxyacid bleach precursor composition according to any one of claims 1-13 wherein the external surfaces of the particulate peroxyacid bleach precursor material are treated with a solution or dispersion of the organic acid compound.

16. A solid peroxyacid bleach precursor composition according to either one of claims 14 15 wherein the organic acid compound is applied as a finely divided spray.

17. A bleaching composition incorporating a solid peroxyacid bleach precursor composition according to any one of claims 1-16 wherein said bleaching composition comprises an inorganic perhydrate bleach.

18. A granular bleaching composition according to any one of claims 1-17 wherein the perhydrate bleach is sodium perborate or sodium percarbonate, present as a dry-added granular material.

19. A granular bleaching composition according to either one of claims 17 18 further incorporating an anionic, nonionic, cationic or ampholytic surfactant or a mixture of any thereof. I K WO 92/13798 PCT/US92/00664 A granular bleaching composition according to claim 19 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 5 by weight have a particle size less than 250 micro-meters.

21. A concentrated granular detergent composition having a bulk density of at least 650g/litre and incorporating a granular bleaching composition according to any one of the preceding claims. AW~ A granular bleaching composition according to claim 19 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 5% by weight have a particle size less than 250 micro-meters. 21. A concentrated granular detergent composition having a bulk density of at least 650g/litre and incorporating a granular bleaching composition according to any one of the preceding claims.

22. A solid peroxyacid bleach precursor composition according to claim 1 substantially as hereinbefore described with reference to any one of the Examples. June, 1995 THE PROCTER GAMBLE COMPANY By their Patent Attorneys PHILLIPS ORMONDE FITZPATRICK 0440 a 00a So o or a o a aa o 0 0 a 0 0 o a .0 0 064 0 0 o~ s* 0 0 0 0 e+ 0 0 a a 0 o e ~-218 3 0 C ti 46 Ii INTERNATIONAL SEARCH REPORT International Application No. PCT/US92/00664i I. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, indicate alf) According to International Patent Clasasfictipn IPC) or to both National Classification and IPC INT. C. C01B 15 U.S. Cl. 252/186.25 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols U.S. 252/186.25, 186.27, 185.38, Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searched s Ill. DOCUMENTS CONSIDERED TO BE RELEVANT s Category Citation of Document, it with indication, where appropriate, of the relevant passages 12 Relevant to Claim No. 13 X US, A, 4,678,594 (PARFOMAK et al) 07 JULY 1987 1-11,14-19,21 Y Published 07/07/87 12-12,20 (Columns 2-8). A US, A, 4,422,950 (KEMPER et al) 27 DECEMBER 1983 1-21 Published 12/27/83 (column 1-4). A US, A, 4,486,327 (MURPHY et al) 04 DECEMBER 1984 1-21 Published 12/04/84 (ABSTRACT). A US, A, 4,853,143 (HARDY et al) 01 AUGUST 1989 1-21 Published 08/01/89 (Columns 6-7). A US, A, 4,444,674 (GRAY) 24 APRIL 1984 1-21 Published 04/24/84 (ABSTRACT). SSpecial categories of cited documents: 1 later document published after the international filing date document defining the general state of the art which is not or priorit date and not in conflct with the application but "A"cited to understand the principle or theory underlying the considered to be of particular relevance invention earlier document but published on or after the international document of particular relevance: the claimed invention filing date cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive step which is cited to establish-the publication date of another document of particular relevancea the claimed invention citation or other special reason (as specified) cannot be considered to involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other metns ments, such combination being obvious to a person skilled document published prior to the international filing date but in the art. later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mi'lg of t. 1 iW Search Report 19 MAY 1992_ International Searching Authority Signa re f Authorized Officer ISA/US J. HONY 1 1 B Z j i I FkmPCTLMO! d sluiQ (Rev.1147) Internatiornal Applica~on No. PCT/US92/00664 Ill. DOCUMENTS CONSIDERED TO BE RELEVANT (CONTINUED FROM SECOND SHEET) Category Citation of Document, with indication, where appropriate, of the relevant passages Relevant to Claim No US, A, 4,938,889 (WILSBERG et al) Published 07/03/9( US, k, 4,731,195 (OLSo&) Published 03/15/U~ (ABSTRACT). 03 JULY 1990 15 MARCH 1988 3 FEBRUARY 1988 3 14 MN.Y 1991 1 1-21 1-21 1-21 1-21 US, A, 4,726,908 (KLRUSE et al) 2: Published 02/23/8J (ABSTACT). us, A, 5,015,408 (REUJSS) Published 05/14/9: (AaSTRACT). J", Fum PCTiISA2IO l~aalmg) (AW.1147) I- 1 -s I International Application No. PT/Us32/OO664 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE This international search report has not been established In respect of certain claims under Article 17(2) for the following reasons: 1.Q Claim numbers because they relate to subject matter it not required to be searched by this Authority, namely: Claim numbers because they relate to parts of the international application that do not comply with the prescribed require- ments to such an extent that no meaningful International search can be carried out i3, specifically: 4-20 3.1 Claim numbnis because thy am dependent claims not dafd in accordnc with the second ad third sentences o PCT Rule6.4.The ove clai re rch ther dens ust be a U VI.Q OBSERaVATIONS WHERE UNITY OF INVENTION IS LACKING 2 1 i This International Searching Authority found multiple inventions in this international application as follows: 1. As all required additional search fees were timely paid by the applicant, this international search report covers all searchable claims of the international application. As only some of the required additional search fees were timely paid by the applicant, this international search report covers only those claims of the international application for which fees were paid, specifically claims: No required additional search fees were timely paid by the applicant. Consequently, this international search report is restricted to the invention first mentioned in the claims; it is covered by claim numbers: 4. As all searchable claims could be searched without effort justifying an additional fee, the international Searching Authority did not invite payment of any additional tee. Remark on Protest 0 The additional search fees were accompanied by applicants protest. Q No protest accompanied the payment of additional search fees. FrmPCtMtSAW210 (stiupwansM s 1147) I