SEPARATE FROM THE BLEACH.

The present invention concerns the improved stability of certain bleaching agents in detergent compositions. In particular it relates to the improved stability of percarbonate bleach particles.

Percarbonate bleach is currently being proposed as an alternative to perborate bleach which has commonly been used in detergent compositions in the past. Sodium percarbonate is an attractive perhydrate for use in detergent compositions because it dissolves readily in water, is weight efficient and, after giving up its available oxygen, provides a useful source of carbonate ions for detergency purposes.

However, the inclusion of percarbonate salts in detergent compositions has been restricted hitherto by the relative instability of the bleach both as is and in use, Sodium percarbonate loses its available oxygen at a significant rate in the presence of moisture, the effect being accelerated at temperatures in excess of about 30°C.

There has therefore been much activity by workers in the field to increase percarbonate stability so as to make it a viable component of detergent formulations. This

activity has tended to concentrate on the protection of the percarbonate by coating the crystalline product or by inclusion of stabilising agents during its manufacture, or both. Thus, while it has proved possible to incorporate percarbonate salts in conventional detergent compositions so as to have acceptable percarbonate stability over periods reflecting normal shelf life, the percarbonate salts have proved complex and expensive to manufacture. This has restricted their broadscale utilisation, as evidenced by the relatively small number of commercially available products containing percarbonate.

Inorganic perhydrate bleaches are invariably incorporated into detergent compositions by dry addition of the crystalline bleach to the remainder of the particulate components towards the end of the detergent manufacturing process. In conventional detergent processing the bulk of these components are in the form of spray-dried granules.

W092/6163, published on 16th April, 1992, discloses detergent compositions in which percarbonate stability is improved by controlling levels of both moisture and heavy metal ions in the composition. This is considered as the closest known prior art.

In the examples a densified, spray-dried component is admixed with a surfactant agglomerate, as well as citrate, silicate, percarbonate and bleach activator. Perfume and suds suppressor (incorporating low levels of paraffin oil and wax) are then sprayed on to the whole composition.

However, the problem remains that if one or more of the components absorb water too readily, then percarbonate degradation may still take place after the finished product has been exposed to atmospheric humidity and the components have absorbed moisture.

It is an object of the present invention to provide a granular detergent composition which has a greatly reduced tendency to absorb water and consequently provides longer term stability of the percarbonate bleach.

It is a further object of the invention to provide a granular detergent incorporating an alkali metal percarbonate bleach displaying acceptable storage stability, in which the percarbonate bleach, for example by surface coating of the percarbonate particles, can be minimised (or avoided completely) thereby maintaining

the rapid solubility rate of percarbonate particles in water.

According to the present invention there is provided at least one granular component comprising paraffin oil and/or wax. The paraffin oil and/or wax, which is water- insoluble and hydrophobic, reduces the tendency of the component to absorb water.

Summary of the Invention

The invention relates to a granular detergent composition comprising at least two particulate components: a) a first particulate component comprising a bleaching agent chosen from the group comprising alkalimetal percarbonate, peroxyacid, perimidic acid or combinations of these, said first particulate component being substantially free of wax; b) a second particulate component comprising from 0.05% to 20% by weight of a water-insoluble paraffin oil and/or wax.

Preferably the second particulate comprises 1 to 5% by weight of paraffin oil and/or wax; and more preferably the paraffin oil has a pour point of from about -40 to

5°C. In an alternative embodiment the wax has a melting point between about 35 and about 110 °C; most preferably it is a microcrystalline wax having a melting point from 60 to 93°C.

It is further preferred that the second particulate component comprises at least 2%, and preferably at least 5% by weight of anionic surfactant. The second particulate component may be advantageously prepared by spray drying. The finished product may comprise at least 40% by weight of the second particulate component.

In another embodiment of the invention the second particulate component further comprises a fabric softening clay.

It is most preferred that the first particulate component, which is substantially free of paraffin oil and wax, comprises less than 0.5% by weight of paraffin oil and wax.

The invention also relates to process for making a granular detergent composition comprising the steps of: (a) preparing an aqueous solution or slurry of detergent ingredients, said solution or slurry further comprising paraffin oil and/or wax;

(b) spray drying said solution or slurry to form a powder; and

(c) admixing said powder with other granular components, said granular components comprising a bleaching agent chosen from the group comprising alkalimetal percarbonate, peroxyacid, peri idic acid or combinations of these, said granular component being substantially free of paraffin oil and wax.

The invention also relates to a process for making a granular detergent composition comprising the steps of:

(a) preparing an aqueous solution or slurry of detergent ingredients;

(b) spray drying said solution or slurry to form a powder;

(c) spraying a liquid onto said powder, said liquid comprising paraffin oil and/or wax; and

(d) admixing said powder with other granular components, said granular component comprising a bleaching agent chosen from the group comprising alkalimetal percarbonate, peroxyacid, perimidic acid or combinations of these, said granular component being substantially free of paraffin oil and of wax.

Detailed Description of the Invention

The essential components of the present invention are parffin oil and/or wax and percarbonate bleach. Suitable paraffin oils, waxes, percarbonates and other bleach precursors will now be described in more detail.

Paraffin Oil and Wax

Paraffin oils are hydrocarbons which may be any aliphatic, alicyclic, aromatic or heterocyclic saturated or unsaturated hydrocarbons having generally from about 12 to about 70 carbon atoms. Paraffins are generally obtained from petroleum by various methods inclusive of fractionation distillation, solvent extraction, cracking, reforming or polymerization of lower olefines or diolefines. Paraffin can also be synthesized from coal thereby using the Fischer-Tropsch process, or by hydrogenation of unsaturated hydrocarbons. Paraffins are-preferably obtained by distillation or solvent extracting the solid residus of petroleum distillation.

The liquid, at room temperature and atmospheric pressure, hydrocarbon herein has normally a pour point in the range of -40°C to 5°C and usually contains from 12 to 40 carbon atoms. The liquid hydrocarbon should normally have a minimum boiling point of not less than

8

110°C (at atmospheric pressure) . Liquid paraffins, preferably of the naphthenic or paraffinic type, also known as mineral white oil are preffered.

Waxes are hydrocarbons which are typically derived from petroleum. Three types of wax may be distinguished (see Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Edition, Wiley,Vol. 24, pages 473 and 474): paraffin wax, microcrystalline wax and semicrystalline wax.

Paraffin wax consists principally of normal alkanes. It is composed of 40-90% normal paraffins and the remainder is C18-C36 isoalkanes and cycloalkanes. The melting point of the wax determines the actual grade and it varies between about 46°C and 71°C. Average molecular weight is between about 350 and 420. A suitable paraffin wax for use in the present invention is BDH Pastillated Paraffin Wax, having a melting point of 51-55 °C

Semicrystalline and microcrystalline waxes contain substantial proportions of hydrocarbons other than normal alkanes. Microcrystalline waxes typically have a melting point between 60°C and 93°C. Average molecular weight is between about 600 and 800.

A particularly preferred microcrystalline wax for use in the present invention is MMP ® , supplied by Shell.

Other waxes suitable for use in the present invention are :

Beeswax;

Vegetable Wax, including Candelilla; Carnauba;

Japan Wax; Ouricury Wax; Douglas-Fir Bark Wax; Rice

Bran Wax; Jojoba; Castor Wax; Bayberry Wax;

Mineral Wax, including Montan Wax and Peat Waxes;

Synthetic Wax, including Polyethylene Waxes;

Fischer-Tropsch Waxes (polymethylene) (45-106 °C) ;

Chemically Modified Hydrocarbon Waxes (86-125 °C) and Substituted Amide Waxes (very high melting point ca 140 °C)

The amount of paraffin oil and wax used in the second particulate component should be from 0.005% to 20% by weight, preferably from 0.5% to 10% by weight and most preferably from 1% to 5% by weight of the second particulate component.

Percarbonate bleach

The granular compositions of the present invention further comprise a granular component comprising a bleaching agent chosen from the group comprising alkalimetal percarbonate, peroxyacid, perimidic acid or

combinations of these. (This component is described herein as the "first particulate component")

Percarbonate will generally be solid and granular in nature. It may be added to granular detergent compositions without additional protection. However, such granular compositions may utilise a coated form of the material which provides better storage stability for the percarbonate in the granular product.

The sodium salt of percarbonate is preferred for use in the present invention. Sodium percarbonate is an addition compound having a formula corresponding to 2Na2C03.3H202, and is available commercially as a crystalline solid. Most commercially available material includes a low level of a heavy metal sequestrant such as EDTA, 1-hydroxyethylidene 1, 1-diphosphonic acid (HEDP) or an a ino-phosphonate, that is incorporated during the manufacturing process. For the purposes of the present invention, the percarbonate may be incorporated into detergent compositions without additional protection, but preferred embodiments of the invention utilise a coated form of the material. Suitable coating materials include the alkali and alkaline earth metal carbonates and sulphates or chlorides. The most preferred coating material comprises a mixed salt of alkali metal sulphate and carbonate. Such coatings together with coating processes have

previously been described in GB 1 466 799, granted to Interox on 9th March, 1977. The weight ratio of the mixed salt coating material to percarbonate lies in the range from 1:200 to 1:4, more preferably from 1:100 to 1:10, and most preferably from 1:50 to 1:20. Preferably, the mixed salt is of sodium sulphate and sodium carbonate which has the general formula Na2S04.n.Na2C03 wherein n is from 0.1 to 3, preferably n is from 0.3 to 1.0 and most preferably n is from 0.2 to 0.5.

Another suitable coating material is sodium silicate of Si02:Na20 ratio from 1.6:1 to 3.4:1, preferably 2.8:1, applied as an aqueous solution to give a level of less than 2% of silicate solids by weight of percarbonate. Magnesium silicate can also be included in the coating.

This percarbonate, when present, is normally incorporated at a level of from 3% to 35% by weight, more preferably from 5% to 30% by weight and most preferably from 8% to 25% by weight of the total composition.

Where the bleaching processes utilising the compositions of the invention are carried out at least in part at temperatures lower than about 60°C, the compositions of the invention may contain bleaching agents more suited to low temperature bleaching. These will include, for example, preformed organic peracids and perimidic acids.

The following are examples of preformed peroxy acids or perimidic acids which are useful in the present invention:

PAP; N,N phthaloylaminoperoxy caproic acid

C-PAP: 2-carboxy-phthaloylaminoperoxy caproic acid

PAPV: N,N phthaloylaminoperoxy valeric acid

NAPAA: Nonyl amide of peroxy adipic acid

H O O N I C II (CH ₂ ) C IIOOH

DPDA: 1 , 12 diperoxydodecanedioic acid

Peroxybenzoic acid and ring substituted peroxybenzoic acid

Monoperoxyphtalic acid (magnesium salt, hexahydrate)

Diperoxybrassylic acid Other detergent ingredients may optionally be incorporated into the compositions of the present invention. Various suitable ingredients will now be described in more detail.

Peroxyacid Bleach Precursor

In a preferred embodiment of the present invention, the composition comprises peroxyacid bleach precursor. The solid peroxyacid bleach precursors of the present invention comprise precursors containing one or more N- or 0- acyl 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 GB-A-836988, 864,798, 1147871 and 2143231 and imides such as are disclosed in GB-A-855735 & 1246338.

Particularly preferred precursor compounds are the N- , ,N ¹ N ¹ tetra acetylated compounds of formula

0 O

1 I

CH ₃ - C C - CH ₃

N - (CH ₂ ) _X - N

CH ₃ - C C - CH ₃

I I

0 0 wherein x can be 0 or an integer between 1 & 6.

Examples include tetra acetyl methylene diamine (TAMD) in which x=l, 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.

Other preferred bleach precursors are the perbenzoic acid precursors such as benzoyloxybenzene sulphonate (BOBS), benzoylcaprolactam, acyloxybenzene sulphonates (NOBS, iso-NOBS) , sugar derivatives (PAG, TAG, and those described in EP 257039) , malonate derivatives (described in EP 517482), cationic precursors (described in EP 512533, EP 508623 and EP 405152), glycolate esters (described in EP507475) and 2-phenyl 4h-3 1-benzoxazin-

4-one, a ino derived bleach activators, benzoxazin-type activators and acyl lactam activators.

Amido Derived Bleach Activators - The amido derived bleach activators which can be employed in the present invention are amide substituted compounds of the general formulas:

or mixtures thereof, wherein R is an alkyl, aryl, or alkaryl group containing from about 1 to about 14

2 carbon atoms, R is an alkylene, arylene or alkarylene group containing from about 1 to about 14 carbon atoms, R is H or an alkyl, aryl, or alkaryl group containing from about 1 to about 10 carbon atoms, and L is essentially any suitable leaving group. A leaving group is any group that is displaced from the bleaching activator as a consequence of the nucleophilic attack on the bleach activator by the perhydroxide anion. This, the perhydrolysis reaction, results in the formation of the peroxycarboxylic acid. Generally, for a group to be a suitable leaving group it must exert an electron attracting effect. It should also form a stable entity so that the rate of the back reaction is negligible. This facilitates the nucleophilic attack by the perhydroxide anion.

The L group must be sufficiently reactive for the reaction to occur within the optimum time frame (e.g., a wash cycle) . However, if L is too reactive, this activator will be difficult to stabilize for use in a bleaching composition. These characteristics are generally paralleled by the pKa of the conjugate acid of the leaving group, although exceptions to this convention are known. Ordinarily, leaving groups that exhibit such behavior are those in which their conjugate acid has a pKa in the range of from about 4 to about 13, preferably from about 6 to about 11 and most preferably from about 8 to about 11.

Preferred bleach activators are those of the above general formula wherein L is selected from the group consisting of:

wherein R is as defined above and Y is -S0 ₃ M or -CO-, M wherein M is an alkali metal, ammonium or substituted ammonium cation, with sodium and potassium being most preferred

Preferred examples of bleach activators of the above formulae include (6-octanamido- caproyl)oxybenzenesulfonate, (6- nonanamidocaproyl)oxybenzenesulfonate, (6-decanamido- caproyl) oxybenzenesulfonate, and mixtures thereof as

described in U.S. Patent 4,634,551, incorporated herein by reference.

- Benzoxazin-type activators, such as disclosed by Hodge et al in U.S. Patent 4,966,723, issued October 30, 1990. A highly preferred activator of the benzoxazin- type is:

- Acyl lactam activators, especially acyl caprolactams and acyl valerolactams of the formulae:

wherein R^ is H, an alkyl, aryl, alkoxyaryl, or alkaryl group containing from 1 to about 12 carbon atoms, or a substituted phenyl group containing from about 6 to about 18 carbons. See copending U.S. applications 08/064,562 and 08/082,270, which disclose substituted benzoyl lactams. Highly preferred lactam activators include benzoyl caprolactam, octanoyl caprolactam, 3, 5, 5-trimethylhexanoyl caprolactam, nonanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam, benzoyl valerolactam, octanoyl valerolactam, decanoyl valerolactam, undecenoyl

valerolactam, nonanoyl valerolactam, 3,5,5- trimethylhexanoyl valerolactam and mixtures thereof. See also U.S. Patent 4,545,784, issued to Sanderson, October 8, 1985, incorporated herein by reference, which discloses acyl caprolactams, including benzoyl caprolactam, adsorbed into sodium perborate.

Bleach precursors will normally be in fine powder or crystalline form in which at least 90% by weight of the powder has a particle size of less than 150 micrometers. However such solid bleach precursors are generally reagglomerated, granulated, encapsulated or spray dried with other components. Such peroxyacid bleach precursor granules are dry blended in the detergent composition and generally have a particle size range of from 300 micrometers to 1500 micrometers. Some bleach precursors are pasty or liquid at room temperature and have to be granulated with porous substrates such as zeolite or silica.

It is_most preferred that a peroxyacid bleach precursor is present at a level of at least 0.5% by weight of the composition. These peroxyacid bleach precursors can be partially replaced by preformed peracids such as N,N phthaloylaminoperoxy acid (PAP), nonyl amide of peroxyadipic acid (NAPAA) , 1,2 diperoxydodecanedioic acid (DPDA) and trimethyl ammonium propenyl imidoperoxy mellitic acid (TAPIMA) .

Photosensitive bleaching agents such as zinc phthalocyanine trisulphonate may also be incorporated into the compositions of the present invention.

Surfactants and Builders

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, 30, 1975. A list of suitable cationic surfactants is given in U.S.P. 4,259,217 issued to Murphy on March 31, 1981.

The finished compositions of the present invention will preferably contain from 2% by weight to 30% by weight, and preferably from 5% to 25% by weight of anionic surfactant.

Water-soluble salts of the higher fatty acids, i.e., "soaps", are useful anionic surfactants in the compositions herein. This includes alkali metal soaps such as the sodium, potassium, ammonium, and alkylammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 12 to about 18 carbon atoms. Soaps can be made by direct saponification of fats and oils or by the

neutralization of free fatty acids. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

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. Preferred sulphonates include alkyl benzene sulphonates having from 9 to 15, most preferably from 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 Ci2 ^-C 18 fatty source, preferably from a C^g-C^g 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 C14-C15 alkyl sulphate and C_β- C _] _g alkyl sulphate in a weight ratio of C14-C1 _. 5: Cιg-C]_g 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 (R) CH ₂ COOM wherein R is a C9-C17 linear or branched alkyl or alkenyl group, R' is a C1-C 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.

Also useful are the sulphonation products of fatty acid methyl esters containing a alkyl group with from 10 to 20 carbon atoms. Preferred are the C16-18 methyl ester sulphonates (MES), or mixtures of C16-18 and C12-14 methyl ester sulphonates.

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.

Especially preferred nonionic surfactants of this type are the C9-C15 primary alcohol ethoxylates containing 3- 9 moles of ethylene oxide per mole of alcohol, particularly the C]_ ₃ -C_5 primary alcohols containing 6-9 moles of ethylene oxide per mole of alcohol and the Cτ_τ_- C15 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 (C _n H _2n O) _t Z _x 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 50% short chain alkyl polyglucosides. Compounds of this type and their use in detergent compositions are disclosed in EP-B 0070074, 0070077, 0075996 and 0094118.

Still another class of nonionic surfactants comprises polyhydroxy fatty acid amides which may be produced by

reacting a fatty acid ester and an N-alkyl polyhydroxy amine. The preferred amine for use in the present invention is N- (Rl) -CH2 (CH20H) -CH2-OH and the preferred ester is a C12-C20 fatty acid methyl ester. Most preferred is the reaction product of N-methyl glucamine with C12-C20 fatty acid methyl ester.

Methods of manufacturing polyhydroxy fatty acid amides have been described in WO 92 6073, published on 16th April, 1992. This application describes the preparation of polyhydroxy fatty acid amides in the presence of solvents. In a highly preferred embodiment of the invention N-methyl glucamine is reacted with a C12-C20 methyl ester. It also says that the formulator of granular detergent compositions may find it convenient to run the amidation reaction in the presence of solvents which comprise alkoxylated, especially ethoxylated (EO 3-8) C12-C14 alcohols.

A further class of surfactants are the semi-polar surfactants such as amine oxides. Suitable amine oxides are selected from mono C _C2 ₀ preferably Cιo~ i4 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 from mono Cg-C _] _ , preferably ^c 10~ ^c 14 N-alkyl or alkenyl ammonium surfactants wherein remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

The surfactant containing particles will further comprise components selected from a wide range of possible ingredients which are commonly used in laundry detergents. Preferably the particles will contain some detergent builder:

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 25% to 60% by weight of the composition, more preferably from 30% to 60% by weight.

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

Whilst a range of aluminosilicate ion exchange materials can be used, preferred sodium aluminosilicate zeolites have the unit cell formula

Na _z [ (A10 ₂ ) _z (Si0 ₂ ) _y ] xH ₂ 0 wherein z and y are at least 6; the molar ratio of z to y is from 1.0 to 0.5 and x is at least 5, preferably from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate materials are in hydrated form and are preferably crystalline, containing from 10% to 28%, more preferably from 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 10 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 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 CaC0 ₃ 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 CaC0 /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 CaC0 ₃ /litre/minute/ (gram/litre) [2 grains/gallon/minute/ (gram/gallon) ] to 390 mg equivalent of CaC0 /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 CaC0 ₃ /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, Zeolite MAP and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material is Zeolite A and has the formula

Na ₁₂ [ (A10 ₂ ) 12 (Si0 ₂ ) ₁₂ ]. xH ₂ 0 wherein x is from 20 to 30, especially 27. Zeolite X of formula Na ₈ 6 t (A10 ₂ ) gg (Si0 ₂ ) ₁₀₆ ] • ^{276 H} 2° ^{is also} suitable, as well as Zeolite HS of formula Nag [ (AL0 ₂ ) ₆ (Si0 ₂ ) ₆ ] 7.5 H ₂ 0) .

Suitable water-soluble monomeric or oligomeric carboxylate builders 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 water-soluble 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 or citric acid, 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-l, 1, 3-propane tricarboxylates described in British Patent No. 1,387,447.

Polycarboxylates containing four carboxy groups include oxydisuccinates disclosed in British Patent No. 1,261,829, 1, 1,2,2-ethane 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.

Another preferred polycarboxylate builder is ethylenediamine-N,N'-disuccinic acid (EDDS) or the alkali metal, alkaline earth metal, ammonium, or substituted ammonium salts thereof, or mixtures thereof.

Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis,cis,cis-tetracarboxylates, cyclopentadienide pentacarboxylates, 2,3,4,5- tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5- 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 co-polymeric 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 maleie anhydride, such copolymers having a molecular weight of from 20,000 to 70,000, especially about 40,000. Such builder polymeric materials may be identical to the polymeric materials as binder materials and coating materials, as described hereinabove. These materials are normally used at levels of from 0.5% to 10% by weight more preferably from 0.75% to 8%, 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 phosphonates and diethylene triamine penta methylene phosphonates, although these materials are less preferred where the minimisation of phosphorus compounds in the compositions is desired.

Water-soluble silicates which are suitable for use in compositions of the present invention may be amorphous or layered.

Such silicates may be characterised by the ratio of Si0 ₂ to Na 0 in their structure. In the present invention, this ratio may typically lie in the range of from 3.3:1 to 2.0:1, preferably 3.3:1 to 2.4:1, more preferably 3.3:1 to 2.8:1, most preferably 3.3:1 to 3.0:1.

Crystalline layered sodium silicates have the general formula

NaMSi _x 0 _2x+ ι . yH ₂ 0 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 164 514 and methods for their prearation are disclosed in DE-A 34 17 649 and DE-A 37 42 043. For the purposs of

31

the present invention, x in the general formula above has a value of 2, 3 or 4 and is preferably 2. More preferably M is sodium and y is ) and preferred examples of this formula comprise the α-, β-,γ-,δ- forms of Na ₂ Si ₂ θ5- These materials are available from Hoechst AG, Germany, as, respectively, NaSKS-5, NaSkS-7, NaSKS-11 and NaSKS-6. The most preferred material is δ- Na ₂ Si ₂ θ5, NaSKS-6.

The particulate component or components which contain the surfactant and builder may be made by any convenient process. Examples of useful processing routes include spray drying, agglomeration, extrusion, prilling etc. One particularly preferred processing route is to spray dry some or all of the surfactant and builder with the paraffin oil and/or wax. Typically spray dried powders have a porosity of greater than 25% and consequently a high tendency to absorb water. The presence of the paraffin oil or wax helps to reduce this.

Another processing route is to spray paraffin oil or molten wax onto a base particle so that it is adsorbed and/or coats the surface of the base particle. Paraffin oil or wax may be sprayed on as a single component, or premixed with other liquid components such as nonionic surfactant.

Still another processing route, suitable for making high bulk density, high detergent active particles is by agglomerating detergent powders and highly viscous surfactant pastes in a high shear mixer. Paraffin oil or wax may also be incorporated into this type of agglomerated component. A more detailed description of such a process is given in the Applicants' co-pending application EP510746, published on 28th October, 1992.

Examples of other components which may be used in laundry detergents, and which may be incorporated into the surfactant particles are described below under "Optional Ingredients"

Optional Ingredients

Detergent compositions of the present invention may, optionally, include anti-redeposition and soil suspension agents, bleach activators, optical brighfeeners, soil release agents, suds suppressors, enzymes, fabric softening agents, perfumes and colours, as well as other ingredients known to be useful in laundry detergents.

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 0.5% to 10% by weight, more preferably from 0.75% to 8%, 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% by weight. These polymers and the previously mentioned homo- or co-polymeric polycarboxylate salts are valuable for improving whiteness maintenance, fabric ash deposition, and cleaning performance on clay, proteinaceous and oxidizable soils in the 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 -s- triazin-6- ylamino) stilbene-2:2 ¹ disulphonate, disodium 4,4 ¹ -bis- (2-morpholino -4-anilino-2-triazin-6-ylaminostilbene-

2:2 ¹ -disulphonate,disodium 4, 4 ¹ -bis- (2, -dianilino-s- triazin-6-ylamino) stilbene-2:2^ - disulphonate, monosodium 4 ¹ ' U-bis- (2, 4-dianilino-s-triazin-6 ylamino) stilbene-2- sulphonate, disodium 4,4 ¹ -bis-(2- anilino-4- (N-methyl-N-2-hydroxyethylamino) -2-triazin-6- ylamino) stilbene-2,2 ¹ - disulphonate, disodium 4,4 ¹ -bis- (4-phenyl-2, 1, 3-triazol-2-yl) stilbene-2,2 ¹ disulphonate, disodium 4, 4 ¹ bis (2-anilino-4- (l-methyl-2- hydroxyethylamino) -s-triazin-6-ylamino) stilbene- 2, 2 ¹ disulphonate and sodium 2 (stilbyl-4 ¹¹ - (naphtho- l ¹ ,2 ¹ :4,5)-l _/ 2,3 - triazole-2 ¹¹ - 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 preferred polymer in accordance with EP-A-0272033 has the formula

< ^CH 3 ^(PBG, 43 ^, 0.75 ^(POK, 0.25 ^(T - ^PO, 2.β ^(T - ^PBG, 0.4 ^{,T PO} - ^H, 0.25 ^{( (PBS,} 43 ^CH 3 ^, 0.75 where PEG is -(OC ₂ H ₄ )0-, PO is (OC ₃ H ₆ 0) and T is (pCOC ₆ H ₄ CO) .

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 alkylated 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 in which the suds suppressor is advantageously releasably incorporated in a water-soluble or water-dispersible, substantially 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^/g, 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 Corning, 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 applieation 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 C _2Q -C ₂ 4

fatty acids, microcrystalline waxes and high MWt copolymers of ethylene oxide and propylene oxide which would 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.

Where microcrystalline waxes are used in the second particulate component of the present invention, it may be possible to reduce or even eliminate other suds suppressors due to the suds suppressing effect of the microcrystalline wax itself.

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, upases, esterases and cellulases conventionally incorporated into detergent compositions. Suitable enzymes are discussed in US Patents 3,519,570 and 3,533,139.

It is a further advantage of the present invention that stability improvements may be obtained for other moisture sensitive components (as well as the bleaching agent) due to the presence of the paraffin oil or wax. Of the optional ingredients listed above, this may be

important for bleach activators, enzymes, soil release polymers and perfume.

Fabric Softening Agents

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 exemplified 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 C]_ ₂ -Ci4 quaternary ammonium salts is disclosed in EP-B-0026527 & 528. Other useful organic fabric softening agents are the dilong chain amides as disclosed 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 25%, more preferably from 8% to 20% 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° ₀ 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 2%, normally from 0.15% to 1.5% by weight. Where a portion 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.

In one highly preferred embodiment of the present invention the wax is incorporated into the same particulate component as the fabric sofening clay. A suitable process for such a composition is described in the Applicants co-pending application number EP634479 published on 18th January, 1995. In that application the benefits of co-agglomerating insoluble silicates such as clays with soluble silicates are described. The present invention encompasses particulate components wherein wax is used as an agglomerating agent either instead of, or in addition to, the soluble silicate (or other binders) . Additionally or alternatively the molten wax may be sprayed onto a base particle which comprises the clay.

EXAMPLES

In these examples the following abbreviations have been used :

LAS : C11-C13 linear alkyl benzene sulphonate TAS : C16-C18 alkyl sulphate Nonionic C45E7: C14-C15 alcohol ethoxylated with an average of 7 ethoxy groups per molecule Polymer : Co-polymer of acrylic and maleic acid, supplied by BASF as Sokolan CP5 ^m .

Che1ant : Diethylene triamine penta (methylene phosphonic acid) , supplied by

Monsanto as Dequest 2060 ™.

Wax : BDH Pastillated Paraffin Wax,

MP 51-55 °C

TAED: N,N,N,N-tetraacetylethylene diamine Percarbonate: Sodium percarbonate having 13 Av02, coated 2.5% Carbonate/Sulphate

All levels are % by weight of a finished detergent composition.

Spray-Dried Example 1 Example 2 Comp . Example

Powders A

LAS 5.9 5.9 5.9

TAS 2.5 2.5 2.5

Zeolite A 20.5 20.5 20.5

Polymer 3.8 3.8 3.8

Sulphate 5.6 5.6 5.6

Silicate 2.9 2.9 2.9

Chelant 0.3 0.3 0.3

Misc/water 7.3 7.4 7.3

Wax 1.0 2.0 —

49.8 50.9 48.8

In Examples 1 and 2 the wax was replaced by paraffin oil.

Dry-mixed

Powders

Percarbonate 20.0 20.0 20.0

TAED 2.5 2.5 2.5

Sodium 12.7 12.7 12.7

Carbonate

Sodium 7.0 5.9 8.0 sulphate

Nonionic C45E7 5.5 5.5 5.5

Minors 2.5 2.5 2.5

(perfume etc.)

100 100 100

Each of the finished products was tested by placing samples in an open dish at 32°C and 80% relative humidity for two days. It was found that the products of examples 1 and 2 both retained more than half of the available oxygen after storage under those conditions. However comparative example A lost more than half of its available oxygen in that time.

Example 3

The spray dried powder of comparative example A was further coated with 2 parts (i.e. 2% by weight of finished product composition) of wax. This was done by spraying wax directly onto a falling mass of the spray dried powder in a drum mixer.

Example 4

The spray dried powder of comparative example A was further coated with 7 parts (i.e. 7% by weight of finished product composition) of a mixture of wax (2 parts) and nonionic C45E7 (5 parts) . The mixture was sprayed onto the spray dried powder using the same process as example 3.

In both of examples 3 and 4 the percarbonate stability (measured as amount of amount of available oxygen retained) was improved compared to comparative example A (without wax) .

Example 5

The blown powder of example 1 was further coated with 2 parts (i.e. 2% by weight of finished product

composition) ^' of wax. This was done by spraying wax directly onto a falling mass of the spray dried powder in a drum mixer. The resulting percarbonate stability was even further improved over that of example 1.

Clay Containing Particles

All levels are % by weight of finished detergent

Example 6 Example 7

Bentonite Clay 15 . 2 15.3

Glycerol 0 . 8 0.8

Wax 1 . 1 1.1

Water

The clay agglomerate of Example 6 was made by agglomerating the bentonite clay together with glycerol wax and an excess of water. The resulting agglomerates were then dried in a fluidised bed to a moisture level of 5% by weight of the clay agglomerate.

In Example 7 the clay agglomerate similar to that in Example 6 was formed in the absence of the wax. Molten wax was then sprayed on to the surfaces of the

agglomerate in the fluid bed dryer which was maitained at a temperature below the melting point of the wax.

A finished product was made up using the clay agglomerates of Examples 6 and 7, together with 40% active anionic surfactant agglomerates (at 21 % by weight of the finished detergent product) , and the dry-mixed powders of Example 1 (total 50.2% by weight of the finished product) , and balanced to 100% with additional sodium sulphate.